Opioid analgesic Acetylfentanyl (acetyl fentanyl) is an opioid analgesic drug that is an analog of fentanyl. Studies have estimated acetylfentanyl to be 15 times more potent than morphine, which would mean that despite being somewhat weaker than fentanyl, it is nevertheless still several times stronger than pure heroin. It has never been licensed for medical use and instead has only been sold on the illicit drug market. Acetylfentanyl was discovered at the same time as fentanyl itself and had only rarely been encountered on the illicit market in the late 1980s. However, in 2013, Canadian police seized 3 kilograms of acetylfentanyl. As a μ-opioid receptor agonist, acetylfentanyl may serve as a direct substitute for oxycodone, heroin or other opioids. Common side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea, and potentially fatal respiratory depression. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.
Safety at a Glance
High Risk- Serotonin syndrome risk
- In 2016, acetylfentanyl was placed under international control, in Schedule I and Schedule IV of the 1961 UN Single C...
- Toxicity: Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most rece...
- Dangerous with: 3-Cl-PCP, 3-HO-PCE, 3-HO-PCP, 3-MeO-PCE (+43 more)
- Overdose risk: fatalities involving acetylfentanyl in the United States had occurred between 2013-2015. Ten fata...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Duration
insufflated
Total: 3 hrs – 4 hrssublingual
Total: 1 hrs – 4 hrsHow It Feels
The onset of acetylfentanyl is startlingly abrupt. Within seconds of administration, a tide of warmth crashes through the body with an urgency that catches even experienced opioid users off guard. There is no gentle preamble, no slow unfurling -- the compound announces itself with a full-body flush that radiates outward from the chest, as though someone has poured heated syrup directly into the bloodstream. The limbs grow impossibly heavy, and gravity itself seems to double, pressing you deeper into whatever surface supports you.
At the peak, consciousness narrows to a single luminous point. The world beyond your immediate sphere of sensation becomes distant, muffled, as though heard through thick glass. Pain -- physical, emotional, existential -- dissolves into a warm chemical silence. There is a euphoria here, but it is not the soaring, expansive joy of stimulants; it is a deep, subterranean contentment, a sense that nothing could possibly be wrong. Breathing slows to a shallow, languid rhythm. Your eyelids droop to half-mast, and the visual field softens at its edges, details smearing into a pleasant blur. Sounds reach you as if traveling through water, each one rounded and stripped of sharpness.
The body becomes a vessel of pure comfort. Muscles that held tension for years seem to release all at once. An itch may crawl across the nose or scalp -- a telltale signature of potent mu-opioid activation -- but even this mild irritation carries a paradoxically pleasant quality, something to scratch absent-mindedly while drifting in the warmth. Nausea can surface without warning, a sudden queasy lurch that reminds you the compound is profoundly pharmacologically active, though it often passes as quickly as it arrives.
What distinguishes acetylfentanyl from its parent compound and analogs is the compressed timeline. The entire arc -- onset to peak to decline -- plays out in a fraction of the time that classical opioids demand. The peak itself is intense but fleeting, lasting perhaps thirty to sixty minutes before the warmth begins to drain away, like bathwater cooling around you. The decline is not gradual; it falls off a cliff, leaving a hollow restlessness in its wake. The body remembers the warmth and immediately begins to miss it. Muscles that were liquid moments ago start to ache. A creeping anxiety replaces the serenity, and the world that was so comfortably distant now presses in with unwelcome sharpness.
The afterglow, such as it is, amounts to a lingering drowsiness and a vaguely unsettled stomach. Sleep may come, but it is shallow and fragmented, punctuated by vivid half-dreams that dissolve on waking. The brevity of the experience is its defining characteristic -- a thunderclap of opioid warmth that arrives and departs with almost surgical speed, leaving behind a body that feels slightly emptied, as though something vital has been borrowed and not quite returned.
Subjective Effects
The effects listed below are based on the Subjective Effect Index (SEI), an open research literature based on anecdotal reports and personal analyses. They should be viewed with a healthy degree of skepticism. These effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects.
Physical Effects
Physical(14)
- Constipation— A slowing or cessation of bowel movements resulting in difficulty passing stool, commonly caused by ...
- Diarrhea— Diarrhea is the occurrence of frequent, loose, or watery bowel movements as a side effect of certain...
- Headache— A painful sensation of pressure, throbbing, or aching in the head that can range from a dull backgro...
- Increased heart rate— A noticeable acceleration of heartbeat that can range from a subtle awareness of one's pulse to a fo...
- Motor control loss— A distinct decrease in the ability to control one's physical body with precision, balance, and coord...
- Nausea— An uncomfortable sensation of queasiness and stomach discomfort that may or may not lead to vomiting...
- Pain relief— A suppression of negative physical sensations such as aches and pains, ranging from dulled awareness...
- Physical euphoria— An intensely pleasurable bodily sensation that can manifest as waves of warmth, tingling electricity...
- Pupil constriction— A visible narrowing of the pupil diameter (miosis) that reduces the size of the dark center of the e...
- Respiratory depression— A dangerous slowing and shallowing of breathing that can progress from barely noticeable reductions ...
- Sedation— A state of deep physical and mental calming that manifests as a progressive desire to remain still, ...
- Seizure— Uncontrolled brain electrical activity causing convulsions and loss of consciousness -- a life-threa...
- Serotonin syndrome— Serotonin syndrome is a potentially fatal medical emergency caused by excessive serotonergic activit...
- Spontaneous physical movements— Spontaneous physical movements are involuntary, seemingly random yet patterned body movements — twit...
Cognitive & Perceptual Effects
Visual(1)
- Drifting— The visual experience of perceiving stationary objects, textures, and surfaces as appearing to flow,...
Cognitive(5)
- Amnesia— A complete or partial inability to form new memories or recall existing ones during and after substa...
- Anxiety— Intense feelings of apprehension, worry, and dread that can range from a subtle background unease to...
- Anxiety suppression— A partial to complete suppression of anxiety and general unease, producing a calm, relaxed mental st...
- Depression— A persistent state of low mood, emotional numbness, hopelessness, and diminished interest or pleasur...
- Sleepiness— A progressive onset of drowsiness, heaviness, and the desire to sleep that pulls the individual towa...
Pharmacology
The recreational effects of this compound occur because opioids structurally mimic endogenous endorphins which are naturally found within the body and also work upon the μ-opioid receptor set. The way in which opioids structurally mimic these natural endorphins results in their physical euphoria, pain relief and anxiolytic effects. This is because endorphins are responsible for reducing pain, causing sleepiness, and feelings of pleasure. They can be released in response to pain, strenuous exercise, orgasm, or general excitement.
Acetylfentanyl's strong potency in relation to that of morphine is largely due to its high lipophilicity, which is the ability of a chemical compound to dissolve in fats, oils, and lipids. Because of this, it can more easily penetrate the central nervous system in comparison to other opioids.
Acetylfentanyl, similar to fentanyl, possesses opioid-like in vitro binding affinity to µ-opioid receptors as well as produce µ-opioid receptor agonist effects. Acetylfentanyl has also been shown to inhibit the twitch response in electrically stimulated vas deferens preparation. Similarly, in another study using tail flick and phenylquinone writhing tests, acetylfentanyl produced analgesic response in mice. Acetylfentanyl has been shown to completely suppress the signs of withdrawal in morphine-dependent monkeys. Furthermore, acetylfentanyl produce morphine-like subjective effects in drug discrimination study. Besides analgesia, fentanyl-like substances, similar to other opioid analgesics, produce a variety of pharmacological effects including alteration in mood, euphoria, drowsiness, respiratory depression, suppression of cough reflex, constriction of pupils (miosis), and impaired gastrointestinal motility.
The United States Drug Enforcement Administration reported in July of 2015 that at least 52 confirmed fatalities involving acetylfentanyl in the United States had occurred between 2013-2015. Ten fatalities attributed to acetylfentanyl overdose were reported during March of 2013 alone in Rhode Island.potentially fatal at heavy dosages and even those with opiate tolerances are at high risk for overdoses. Once the acetylfentanyl is in the user's system, it is extremely difficult to stop its course because of the nature of absorption. Because of the extremely high strength of pure acetylfentanyl powder, it is very difficult to dilute appropriately, and often the resulting mixture may be far too strong and, therefore, very dangerous. It is also lethal when mixed with depressants like alcohol or benzodiazepines]].
Like most opioids, unadulterated acetylfentanyl at appropriate dosages does not cause many long-term complications other than extreme physical dependence and constipation. Outside of physical and psychological addiction, the harmful aspects of opioid usage are associated with not taking the necessary precautions in regards to its administration, overdosing on the substance and using impure products within the substance. It is important to consider that particular care must be taken with acetylfentanyl due to its extreme potency and ability to be absorbed through the skin.unintentionally spilling a very small amount of acetylfentanyl on one's skin could result in a fatal overdose.
Heavy dosages of acetylfentanyl can result in respiratory depression, leading onto fatal or dangerous levels of anoxia (oxygen deprivation). This occurs because the breathing reflex is suppressed by agonism of μ-opioid receptor proportional to the dosage consumed.
Acetylfentanyl can also cause nausea and vomiting; a significant number of deaths attributed to opioid overdose are caused by aspiration of vomit by an unconscious victim. This is when an unconscious or semi-conscious user who is lying on their back vomits into their mouth and unknowingly suffocates. It can be prevented by ensuring that one is lying on their side with their head tilted downwards so that the airways cannot be blocked in the event of vomiting while unconscious (also known as the recovery position). In case of overdose, it is advised to administer a dose of naloxone intravenously or intramuscularly to reverse the effects of opioid agonism.
It is strongly recommended that one use harm reduction practices when using this substance.
As with other opioids,extremely addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal symptoms may occur if a person suddenly stops their usage.develops with prolonged and repeated use. The rate at which this occurs develops at different rates for different effects, with tolerance to the constipation-inducing effects developing particularly slowly for instance. This results in users having to administer increasingly large doses to achieve the same effects. After that,3 - 71 - 2 weeks to be back at baseline (in the absence of further consumption). Acetylfentanyl presents cross-tolerance with Cross-all other opioids, meaning that after the consumption of acetylfentanyl all opioids will have a reduced effect.
The risk of fatal opioid overdoses rise sharply after a period of cessation and relapse, largely because of reduced tolerance. To account for this lack of tolerance, it is safer to only dose a fraction of one's usual dosage if relapsing. It has also been found that the environment one is in can play a role in opioid tolerance. In one scientific study, rats with the same history of heroin administration were significantly more likely to die after receiving their dose in an environment not associated with the drug in contrast to a familiar environment.
- Serotonin syndrome risk
In 2016, acetylfentanyl was placed under international control, in Schedule I and Schedule IV of the 1961 UN Single Convention on Narcotic Drugs.
Austria: Acetylfentanyl is a controlled substance under the SMG.
Canada: Acetylfentanyl is a Schedule 1 controlled substance as it is an analog of fentanyl.
China: Acetylfentanyl is a controlled substance as of October 1, 2015.
Cyprus: Acetylfentanyl is a controlled substance since 2013.
Estonia: Acetylfentanyl is a controlled substance as of June 8, 2015.
Finland: Acetylfentanyl is a Liite 4 (Annex 4) controlled substance as of September 28, 2015.
Germany: Acetylfentanyl is controlled under Anlage II BtMG (Narcotics Act, Schedule II) as of June 20, 2017. It is illegal to manufacture, possess, import, export, buy, sell, procure or dispense it without a license.
Ireland: Acetylfentanyl is listed in Schedule I of the Misuse of Drugs Regulation 1988.
Latvia: Acetylfentanyl is a List I controlled substance.
Lithuania: Acetylfentanyl is a controlled substance.
Norway: Acetylfentanyl is controlled by the Medicines Act.
Poland: Acetylfentanyl is controlled under new psychoactive substances control legislation.
Russia: Acetylfentanyl is a Schedule I controlled substance.
Sweden: Acetylfentanyl is a controlled substance as of August 18, 2015.
Switzerland: Acetylfentanyl is a controlled substance specifically named under Verzeichnis D.
Turkey: Acetylfentanyl is illegal in Turkey as of February 2016.
United Kingdom: Acetylfentanyl was made a Class A controlled substance as an analogue of fentanyl in 1986.
United States: Acetylfentanyl is a Schedule I controlled substance as of May 2015. The illegality of the drug has been supported by the charges against individuals for distribution of acetylfentanyl and possession with the intent to distribute acetylfentanyl. One individual was sentenced to 3 years in prison by a federal court.
Responsible use
Volumetric liquid dosing
Opioid
Fentanyl
Heroin
Morphine
Acetylfentanyl (Wikipedia)
Acetylfentanyl (Erowid Vault)
Acetylfentanyl (Isomer Design)
Detection Methods
Standard Drug Panel Inclusion
Acetylfentanyl is a fentanyl analogue that is not detected on standard 5-panel or 10-panel immunoassay drug screens. Standard opiate immunoassays target the morphine backbone and do not cross-react with the fentanyl scaffold. Detection requires a fentanyl-specific immunoassay channel, which is available on some expanded panels (typically 14-panel or custom clinical panels), or dedicated fentanyl test strips.
Urine Detection
Acetylfentanyl can be detected in urine for approximately 1 to 4 days after exposure, depending on the dose and the individual's metabolic rate. Fentanyl analogues are extensively metabolized by hepatic cytochrome P450 3A4 enzymes, producing norfentanyl-type metabolites and hydroxylated derivatives. These metabolites are the primary urinary markers. The potency of fentanyl analogues means that absolute quantities in urine may be very low, requiring sensitive analytical methods.
Blood and Saliva Detection
Blood concentrations of Acetylfentanyl are detectable for approximately 12 to 24 hours. Due to the extreme potency of fentanyl analogues, blood concentrations in the low nanogram-per-milliliter range are pharmacologically significant, and detection requires sensitive LC-MS/MS methods. Oral fluid testing for fentanyl analogues is possible but not widely deployed.
Hair Follicle Detection
Hair follicle testing can detect fentanyl analogues for up to 90 days. Some expanded hair testing panels include fentanyl and norfentanyl. Given the very low doses involved with potent fentanyl analogues, hair concentrations may be at or near the limit of detection, and a negative hair test does not necessarily exclude use.
Fentanyl Test Strips
Immunochromatographic fentanyl test strips (such as BTNX or DanceSafe strips) are widely used for harm reduction. These strips can detect fentanyl and many fentanyl analogues including Acetylfentanyl at concentrations above approximately 0.25 to 1 mcg/mL in solution. Cross-reactivity with specific analogues varies; some novel analogues may produce false negatives. Test strips are designed for point-of-use screening of drug supplies, not biological specimens.
Confirmatory Testing
LC-MS/MS is the gold standard for identifying Acetylfentanyl in biological matrices. This technique can detect and quantify fentanyl analogues at sub-nanogram-per-milliliter concentrations. Reference standards specific to Acetylfentanyl are required for positive identification. GC-MS can also detect fentanyl analogues but typically requires derivatization for optimal sensitivity.
Reagent Testing
Marquis reagent shows no reaction or a faint brown with most fentanyl analogues. Mecke reagent may produce a slight color change. Standard reagent kits cannot reliably detect or identify fentanyl analogues due to the very small quantities involved (often microgram-level doses). Fentanyl-specific test strips are far more appropriate than reagent kits for harm reduction screening of this substance class.
Interactions
| Substance | Status | Note |
|---|---|---|
| 3-Cl-PCP | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| 3-HO-PCE | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| 3-HO-PCP | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| 3-MeO-PCE | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| 3-MeO-PCMo | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| 3-MeO-PCP | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| 4-MeO-PCP | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Alcohol | Dangerous | — |
| Atropa belladonna | Dangerous | Compounding CNS depression with anticholinergic effects; risk of cardiac events and respiratory failure |
| Benzodiazepines | Dangerous | — |
| Cake | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| Datura | Dangerous | Compounding CNS depression with anticholinergic effects; risk of cardiac events and respiratory failure |
| Deschloroetizolam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Deschloroketamine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Desomorphine | Dangerous | Compounding respiratory depression and overdose risk |
| Diclazepam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Diphenhydramine | Dangerous | Compounding CNS depression with anticholinergic effects; risk of cardiac events and respiratory failure |
| Diphenidine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Ephenidine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Eszopiclone | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| Etizolam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Flubromazepam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Flubromazolam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Flunitrazepam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Flunitrazolam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Gaboxadol | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| GBL | Dangerous | — |
| GHB | Dangerous | — |
| Harmala alkaloid | Dangerous | Risk of serotonin syndrome and severe respiratory depression; potentially fatal |
| HXE | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Inhalants | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Ketamine | Dangerous | — |
| Lorazepam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Memantine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Mephenaqualone | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| Metizolam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| Midazolam | Dangerous | Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths |
| MXiPr | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Naloxone | Dangerous | Compounding respiratory depression and overdose risk |
| Nicotine | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| Nifoxipam | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| O-PCE | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| PCE | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Peganum harmala | Dangerous | Risk of serotonin syndrome and severe respiratory depression; potentially fatal |
| Pentobarbital | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| Phenobarbital | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| SAMe | Dangerous | Severe respiratory depression risk; leading cause of polydrug overdose |
| 3-FMA | Caution | Stimulants mask opioid sedation, increasing overdose risk when the stimulant wears off |
| 4-MMC | Caution | Stimulants mask opioid sedation, increasing overdose risk when the stimulant wears off |
| 8-Chlorotheophylline | Caution | Stimulants mask opioid sedation, increasing overdose risk when the stimulant wears off |
| Adrafinil | Caution | Stimulants mask opioid sedation, increasing overdose risk when the stimulant wears off |
| Benzydamine | Caution | Stimulants mask opioid sedation, increasing overdose risk when the stimulant wears off |
| Nitrous | Uncertain | — |
| PCP | Uncertain | — |
| 1,3-Butanediol | Low Risk & No Synergy | No significant pharmacological interaction; opioids may slightly dull the psychedelic experience |
| 25E-NBOH | Low Risk & No Synergy | No significant pharmacological interaction; opioids may slightly dull the psychedelic experience |
| 2C-T | Low Risk & No Synergy | No significant pharmacological interaction; opioids may slightly dull the psychedelic experience |
History
Acetylfentanyl belongs to the opioid class of substances, which has a history spanning thousands of years from the ancient use of opium poppy to modern synthetic and semi-synthetic analogues.
The isolation of morphine from opium in 1804 by Friedrich Sertürner marked the beginning of modern opioid pharmacology. Subsequent developments included the synthesis of heroin (diacetylmorphine) in 1874, the development of numerous semi-synthetic and fully synthetic opioids throughout the 20th century, and the identification of endogenous opioid receptors and peptides in the 1970s.
The opioid crisis of the early 21st century, driven largely by overprescription of pharmaceutical opioids and the subsequent emergence of illicit fentanyl and its analogues, represents one of the most significant public health challenges in modern history. This crisis has fundamentally reshaped discussions around opioid prescribing, addiction treatment, and harm reduction policy.
Acetylfentanyl exists within this complex pharmacological and social context, with its history shaped by its development, clinical utility, and the broader dynamics of opioid use and regulation.
Harm Reduction
As with other opioids,extremely addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal symptoms may occur if a person suddenly stops their usage.develops with prolonged and repeated use. The rate at which this occurs develops at different rates for different effects, with tolerance to the constipation-inducing effects developing particularly slowly for instance. This results in users having to administer increasingly large doses to achieve the same effects. After that,3 - 71 - 2 weeks to be back at baseline (in the absence of further consumption). Acetylfentanyl presents cross-tolerance with Cross-all other opioids, meaning that after the consumption of acetylfentanyl all opioids will have a reduced effect.
The risk of fatal opioid overdoses rise sharply after a period of cessation and relapse, largely because of reduced tolerance. To account for this lack of tolerance, it is safer to only dose a fraction of one's usual dosage if relapsing. It has also been found that the environment one is in can play a role in opioid tolerance. In one scientific study, rats with the same history of heroin administration were significantly more likely to die after receiving their dose in an environment not associated with the drug in contrast to a familiar environment.
- Serotonin syndrome risk
In 2016, acetylfentanyl was placed under international control, in Schedule I and Schedule IV of the 1961 UN Single Convention on Narcotic Drugs.
- Austria: A
Toxicity & Safety
Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.
The United States Drug Enforcement Administration reported in July of 2015 that at least 52 confirmed fatalities involving acetylfentanyl in the United States had occurred between 2013-2015. Ten fatalities attributed to acetylfentanyl overdose were reported during March of 2013 alone in Rhode Island.
Fentanyl is potentially fatal at heavy dosages and even those with opiate tolerances are at high risk for overdoses. Once the acetylfentanyl is in the user's system, it is extremely difficult to stop its course because of the nature of absorption. Because of the extremely high strength of pure acetylfentanyl powder, it is very difficult to dilute appropriately, and often the resulting mixture may be far too strong and, therefore, very dangerous. It is also potentially lethal when mixed with depressants like alcohol or benzodiazepines.
Like most opioids, unadulterated acetylfentanyl at appropriate dosages does not cause many long-term complications other than extreme physical dependence and constipation. Outside of physical and psychological addiction, the harmful aspects of opioid usage are associated with not taking the necessary precautions in regards to its administration, overdosing on the substance and using impure products within the substance. It is important to consider that particular care must be taken with acetylfentanyl due to its extreme potency and ability to be absorbed through the skin. This means that simply unintentionally spilling a very small amount of acetylfentanyl on one's skin could result in a fatal overdose.
Heavy dosages of acetylfentanyl can result in respiratory depression, leading onto fatal or dangerous levels of anoxia (oxygen deprivation). This occurs because the breathing reflex is suppressed by agonism of μ-opioid receptor proportional to the dosage consumed.
Acetylfentanyl can also cause nausea and vomiting; a significant number of deaths attributed to opioid overdose are caused by aspiration of vomit by an unconscious victim. This is when an unconscious or semi-conscious user who is lying on their back vomits into their mouth and unknowingly suffocates. It can be prevented by ensuring that one is lying on their side with their head tilted downwards so that the airways cannot be blocked in the event of vomiting while unconscious (also known as the recovery position). In case of overdose, it is advised to administer a dose of naloxone intravenously or intramuscularly to reverse the effects of opioid agonism.
It is strongly recommended that one use harm reduction practices when using this substance.
Tolerance and addiction potential
As with other opioids, the chronic use of acetylfentanyl can be considered extremely addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal symptoms may occur if a person suddenly stops their usage.
Tolerance to many of the effects of acetylfentanyl develops with prolonged and repeated use. The rate at which this occurs develops at different rates for different effects, with tolerance to the constipation-inducing effects developing particularly slowly for instance. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). Acetylfentanyl presents cross-tolerance with all other opioids, meaning that after the consumption of acetylfentanyl all opioids will have a reduced effect.
The risk of fatal opioid overdoses rise sharply after a period of cessation and relapse, largely because of reduced tolerance. To account for this lack of tolerance, it is safer to only dose a fraction of one's usual dosage if relapsing. It has also been found that the environment one is in can play a role in opioid tolerance. In one scientific study, rats with the same history of heroin administration were significantly more likely to die after receiving their dose in an environment not associated with the drug in contrast to a familiar environment.
Dangerous interactions
Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).
Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.
Alcohol - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. Place affected patients in the recovery position to prevent vomit aspiration from excess. Memory blackouts are likely
Stimulants - Stimulants increase respiration rate which allows for a higher dose of opiates than would otherwise be used. If the stimulant wears off first then the opiate may overcome the user and cause respiratory arrest.
Benzodiazepines - Central nervous system and/or respiratory-depressant effects may be additively or synergistically present. The two substances potentiate each other strongly and unpredictably, very rapidly leading to unconsciousness. While unconscious, vomit aspiration is a risk if not placed in the recovery position blackouts/memory loss likely.
DXM - Generally considered to be toxic. CNS depression, difficulty breathing, heart issues, and liver toxicity have been observed. Additionally if one takes DXM, their tolerance of opiates goes down slightly, thus causing additional synergistic effects.
GHB/GBL - The two substances potentiate each other strongly and unpredictably, very rapidly leading to unconsciousness. While unconscious, vomit aspiration is a risk if not placed in the recovery position
Ketamine - Both substances bring a risk of vomiting and unconsciousness. If the user falls unconscious while under the influence there is a severe risk of vomit aspiration if they are not placed in the recovery position.
MAOIs - Coadministration of monoamine oxidase inhibitors (MAOIs) with certain opioids has been associated with rare reports of severe adverse reactions. There appear to be two types of interaction, an excitatory and a depressive one. Symptoms of the excitatory reaction may include agitation, headache, diaphoresis, hyperpyrexia, flushing, shivering, myoclonus, rigidity, tremor, diarrhea, hypertension, tachycardia, seizures, and coma. Death has occurred in some cases.
MXE - MXE can potentiate the effects of opioids but also increases the risk of respiratory depression and organ toxicity.
Nitrous - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspiration is a risk if not placed in the recovery position. Memory blackouts are common.
PCP - PCP may reduce opioid tolerance, increasing the risk of overdose.
Tramadol - Increased risk of seizures. Tramadol itself is known to induce seizures and it may have additive effects on seizure threshold with other opioids. Central nervous system- and/or respiratory-depressant effects may be additively or synergistically present.
Grapefruit - While grapefruit is not psychoactive, it may affect the metabolism of certain opioids. Tramadol, oxycodone, and fentanyl are all primarily metabolized by the enzyme CYP3A4, which is potently inhibited by grapefruit juice. This may cause the drug to take longer to clear from the body. it may increase toxicity with repeated doses. Methadone may also be affected. Codeine and hydrocodone are metabolized by CYP2D6. People who are on medicines that inhibit CYP2D6, or that lack the enzyme due to a genetic mutation will not respond to codeine as it can not be metabolized into its active product: morphine.
Serotonin syndrome risk
Combinations with the following substances can cause dangerously high serotonin levels. Serotonin syndrome requires immediate medical attention and can be fatal if left untreated.
MAOIs - Such as banisteriopsis caapi, syrian rue, phenelzine, selegiline, and moclobemide.
Serotonin releasers - Such as MDMA, 4-FA, methamphetamine, methylone and αMT.
SSRIs - Such as citalopram and sertraline
SNRIs - Such as tramadol and venlafaxine
Addiction Potential
extremely addictive with a high potential for abuse
Overdose Information
fatalities involving acetylfentanyl in the United States had occurred between 2013-2015. Ten fatalities attributed to acetylfentanyl overdose were reported during March of 2013 alone in Rhode Island.potentially fatal at heavy dosages and even those with opiate tolerances are at high risk for overdoses. Once the acetylfentanyl is in the user's system, it is extremely difficult to stop its course because of the nature of absorption. Because of the extremely high strength of pure acetylfentanyl powder, it is very difficult to dilute appropriately, and often the resulting mixture may be far too strong and, therefore, very dangerous. It is also lethal when mixed with depressants like alcohol or benzodiazepines]].
Like most opioids, unadulterated acetylfentanyl at appropriate dosages does not cause many long-term complications other than extreme physical dependence and constipation. Outside of physical and psychological addiction, the harmful aspects of opioid usage are associated with not taking the necessary precautions in regards to its administration, overdosing on the substance and using impure products within the substance. It is important to consider that particular care must be taken with acetylfentanyl due to its extreme potency and ability to be absorbed through the skin.unintentionally spilling a very small amount of acetylfentanyl on one's skin could result in a fatal overdose.
Heavy dosages of acetylfentanyl can result in respiratory depression, leading onto fatal or dangerous levels of anoxia (oxygen deprivation). This occurs because the breathing reflex is suppressed by agonism of μ-opioid receptor proportional to the dosage consumed.
Acetylfentanyl can also cause nausea and vomiting; a significant number of deaths attributed to opioid overdose are caused by aspiration of vomit by an unconscious victim. This is when an unconscious or semi-conscious user who is lying on their back vomits into their mout
Dangerous Interactions
The combinations listed below may be life-threatening. Independent research should always be conducted to ensure safety when combining substances.
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Compounding CNS depression with anticholinergic effects; risk of cardiac events and respiratory failure
Severe respiratory depression risk; leading cause of polydrug overdose
Compounding CNS depression with anticholinergic effects; risk of cardiac events and respiratory failure
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Compounding respiratory depression and overdose risk
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Compounding CNS depression with anticholinergic effects; risk of cardiac events and respiratory failure
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Severe respiratory depression risk; leading cause of polydrug overdose
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Severe respiratory depression risk; leading cause of polydrug overdose
Risk of serotonin syndrome and severe respiratory depression; potentially fatal
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Severe respiratory depression risk; leading cause of polydrug overdose
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Severe respiratory depression; this combination is the leading cause of prescription drug overdose deaths
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Compounding respiratory depression and overdose risk
Severe respiratory depression risk; leading cause of polydrug overdose
Severe respiratory depression risk; leading cause of polydrug overdose
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Risk of serotonin syndrome and severe respiratory depression; potentially fatal
Severe respiratory depression risk; leading cause of polydrug overdose
Severe respiratory depression risk; leading cause of polydrug overdose
Severe respiratory depression risk; leading cause of polydrug overdose
Tolerance
| Full | develops with prolonged and repeated use |
| Half | 3 - 7 days |
| Zero | 1 - 2 weeks |
Cross-tolerances
Legal Status
In 2016, acetylfentanyl was placed under international control, in Schedule I and Schedule IV of the 1961 UN Single Convention on Narcotic Drugs.
Austria: Acetylfentanyl is a controlled substance under the SMG.
Canada: Acetylfentanyl is a Schedule 1 controlled substance as it is an analog of fentanyl.
China: Acetylfentanyl is a controlled substance as of October 1, 2015.
Cyprus: Acetylfentanyl is a controlled substance since 2013.
Estonia: Acetylfentanyl is a controlled substance as of June 8, 2015.
Finland: Acetylfentanyl is a Liite 4 (Annex 4) controlled substance as of September 28, 2015.
Germany: Acetylfentanyl is controlled under Anlage II BtMG (Narcotics Act, Schedule II) as of June 20, 2017. It is illegal to manufacture, possess, import, export, buy, sell, procure or dispense it without a license.
Ireland: Acetylfentanyl is listed in Schedule I of the Misuse of Drugs Regulation 1988.
Latvia: Acetylfentanyl is a List I controlled substance.
Lithuania: Acetylfentanyl is a controlled substance.
Norway: Acetylfentanyl is controlled by the Medicines Act.
Poland: Acetylfentanyl is controlled under new psychoactive substances control legislation.
Russia: Acetylfentanyl is a Schedule I controlled substance.
Sweden: Acetylfentanyl is a controlled substance as of August 18, 2015.
Switzerland: Acetylfentanyl is a controlled substance specifically named under Verzeichnis D.
Turkey: Acetylfentanyl is illegal in Turkey as of February 2016.
United Kingdom: Acetylfentanyl was made a Class A controlled substance as an analogue of fentanyl in 1986.
United States: Acetylfentanyl is a Schedule I controlled substance as of May 2015. The illegality of the drug has been supported by the charges against individuals for distribution of acetylfentanyl and possession with the intent to distribute acetylfentanyl. One individual was sentenced to 3 years in prison by a federal court.
Responsible use
Volumetric liquid dosing
Opioid
Fentanyl
Acetylfentanyl (Wikipedia)
Acetylfentanyl (Erowid Vault)
Acetylfentanyl (Isomer Design)
Experience Reports (2)
Tips (3)
Opioid tolerance and cross-tolerance are complex with Acetylfentanyl. Switching between different opioids requires careful dose conversion. Do not assume equivalent effects at standard conversion ratios; start lower than calculated.
The highest risk of fatal overdose from Acetylfentanyl comes after a tolerance break, whether from rehab, jail, hospital, or even a few days of abstinence. Your old dose can kill you. Always start at a fraction of your previous dose.
In most US states, Good Samaritan laws protect you from drug charges if you call 911 for an overdose. Never hesitate to call emergency services. A legal charge is infinitely preferable to a death.
See Also
References (4)
- Opioid receptors — Pasternak & Pan Annual Review of Pharmacology (2013)paper
- PubChem: Acetylfentanyl
PubChem compound page for Acetylfentanyl (CID: 527015)
pubchem - Acetylfentanyl - TripSit Factsheet
TripSit factsheet for Acetylfentanyl
tripsit - Acetylfentanyl - Wikipedia
Wikipedia article on Acetylfentanyl
wikipedia