Comprehensive list of compounds structurally related to fentanyl
The following is a list of fentanyl analogues (sometimes referred to as fentalogs), and includes both compounds developed by pharmaceutical companies for legitimate medical use, and those which have been sold as designer drugs. The latter have been reported to national drug control agencies such as the DEA, and some to transnational agencies such as the EMCDDA and UNODC. This is not a comprehensive or exhaustive list of fentanyl analogues, as more than 1400 compounds from this family have been described in the scientific and patent literature. However, this list does include many notable compounds that have reached late-stage human clinical trials, and compounds which have been sold as designer drugs, as well as representative examples of significant structural variations reported in the scientific and patent literature. The structural variations among fentanyl analogues can impart profound pharmacological differences between each other, especially regarding potency and efficacy.
In the United States, the Drug Enforcement Administration (DEA) placed the class of "Fentanyl-Related Substances" on the list of Schedule I drugs in 2018, making it illegal to manufacture, distribute, or possess fentanyl analogs, with very broad terminology being used in its scheduling. Regarding the temporary control of fentanyl-related substances, Schedule I was extended through December 31, 2024 by Public Law 117-328.
Safety at a Glance
High Risk- General Principles
- Start low, go slow: Always begin with a low dose, especially with unfamiliar batches or new substances. Individual se...
- Toxicity: The toxicity and long-term health effects of N-(2C)-fentanyl have not been comprehensively studied in scientific lite...
- Overdose risk: Limited specific overdose data is available for N-(2C)-fentanyl. In the absence of compound-speci...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Duration
insufflated
Total: 1 hrs – 3 hrsHow It Feels
The onset of N-(2C)-fentanyl is rapid and forceful, arriving within minutes of administration with a dense, surging warmth that floods the body from center to periphery. Like other fentanyl analogues, its speed is one of its defining and most dangerous characteristics — the transition from baseline to full effect occurs in a window so narrow that the ability to judge dosage in real time is effectively eliminated. The warmth is immediate and engulfing, accompanied by a sudden heaviness in the limbs and an involuntary closing of the eyes as the first wave of euphoria crests.
The peak establishes itself within minutes and is characterized by an intense, almost narcotic sedation that drives the body toward immobility. The euphoria is dense and opaque — a thick, chemical satisfaction that leaves little room for nuance or reflection. Pain vanishes entirely. Anxiety is chemically silenced. The body lies still, heavy and warm, breathing at a rate that may become dangerously depressed. Nausea can be severe. The histamine response produces itching across the face, chest, and arms. The pupils constrict to points.
Cognitively, the state is one of near-total suspension. Thought does not flow or wander — it simply ceases to be necessary. There is no introspection, no insight, no emotional processing. There is only the warmth and the absence of everything that the warmth has displaced. This pharmacological simplicity — this reduction of consciousness to a single, overwhelming signal — is characteristic of the potent synthetic opioids.
The duration is brief, typically one to three hours, and the offset is steep. The warmth withdraws rapidly, leaving a cold, hollow restlessness and an immediate, visceral awareness of the comfort that has departed. The body begins to ache. The mind begins to race. The compulsion to redose arrives with a speed and intensity proportional to the compound's potency — which is to say, with frightening urgency. As with all fentanyl analogues, the margin between active dose and lethal dose is terrifyingly narrow, and the subjective experience offers no reliable warning of where that boundary lies.
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(6)
- Constipation— A slowing or cessation of bowel movements resulting in difficulty passing stool, commonly caused by ...
- 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...
- 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, ...
Cognitive & Perceptual Effects
Cognitive(3)
- Anxiety— Intense feelings of apprehension, worry, and dread that can range from a subtle background unease to...
- Depression— A persistent state of low mood, emotional numbness, hopelessness, and diminished interest or pleasur...
- Introspection— An enhanced state of self-reflective awareness in which one feels drawn to examine their own thought...
Pharmacology
As a fentanyl analogue, N-(2C)-fentanyl is expected to act as a potent agonist at mu-opioid receptors (MOR), with activity likely also at kappa and delta opioid receptor subtypes. The precise binding affinity, selectivity profile, and potency relative to fentanyl have not been comprehensively characterized in published literature, which is itself a significant safety concern. Fentanyl-class compounds generally exhibit rapid onset due to high lipophilicity enabling fast blood-brain barrier penetration. The 2C-phenethylamine structural modification may confer additional pharmacological properties at serotonin or other monoamine receptors, though this is speculative without definitive pharmacological data.
Detection Methods
Urine Detection
N-2C-Fentanyl is a novel fentanyl analog with limited published pharmacological and analytical data. Standard opiate immunoassays do NOT detect fentanyl analogs. Fentanyl-specific immunoassays may show variable cross-reactivity with N-2C-fentanyl depending on the structural similarity recognized by the antibody. The urine detection window by LC-MS/MS is estimated at 2 to 4 days, based on the general pharmacokinetics of fentanyl analogs.
Blood and Serum Detection
Very limited pharmacokinetic data exists for this compound. By analogy with other fentanyl analogs, the half-life is estimated at 3 to 12 hours. Blood detection by LC-MS/MS is estimated at 12 to 36 hours.
Hair Follicle Detection
Hair testing for N-2C-fentanyl has not been validated. Reference standards may not be commercially available from routine suppliers.
Standard Drug Panel Inclusion
N-2C-Fentanyl is NOT detected on any standard drug panel. Even fentanyl-specific immunoassays may not cross-react with this structural variant. Only LC-MS/MS methods that specifically target novel fentanyl analogs have any potential for detection.
Confirmatory Methods
LC-MS/MS at a laboratory with novel fentanyl analog capabilities is the only reliable identification method. High-resolution mass spectrometry (HRMS) may be necessary for identification if reference standards are unavailable.
Interactions
No documented interactions.
History
N-(2C)-fentanyl is a psychoactive substance whose history reflects the broader patterns of drug discovery, use, and regulation that characterize the modern era of psychopharmacology. Detailed historical documentation specific to N-(2C)-fentanyl may be limited, particularly for newer research chemicals or less commonly encountered compounds.
Harm Reduction
General Principles
- Start low, go slow: Always begin with a low dose, especially with unfamiliar batches or new substances. Individual sensitivity varies enormously.
- Test your substances: Use reagent test kits to verify identity and check for dangerous adulterants. Consider using drug checking services where available.
- Research thoroughly: Understand expected dose ranges, duration, potential interactions, and contraindications before use.
- Never use alone: Have a trusted, sober person present, especially with new substances or higher doses.
- Set and setting: Your mindset and environment profoundly influence the experience. Choose a safe, comfortable environment and ensure you're in a stable psychological state.
N-(2C)-fentanyl-Specific Considerations
As with any psychoactive substance, individual sensitivity to N-(2C)-fentanyl can vary significantly. Start with conservative doses, thoroughly research the compound's specific risk profile, and consider the broader context of your physical and mental health before use.
Toxicity & Safety
The toxicity and long-term health effects of N-(2C)-fentanyl have not been comprehensively studied in scientific literature. The absence of evidence of harm is not evidence of absence — novel or under-researched substances may carry undocumented risks.
General principles of toxicological concern apply: repeated exposure to any psychoactive substance can lead to neuroadaptive changes, potential organ toxicity, and psychological dependence. The risk profile is influenced by dose, frequency of use, route of administration, individual vulnerability factors, and co-ingested substances.
Given the limited safety data available, extra caution is warranted. Use the lowest effective dose, space sessions widely, and monitor for any adverse physical or psychological changes.
It is strongly recommended that one use harm reduction practices when using this substance.
Overdose Information
Limited specific overdose data is available for N-(2C)-fentanyl. In the absence of compound-specific information, general principles apply:
If someone exhibits signs of medical distress after using N-(2C)-fentanyl — difficulty breathing, severe confusion, seizures, chest pain, extremely elevated temperature, or loss of consciousness — treat it as a medical emergency. Call emergency services and be forthcoming about what was consumed. Medical professionals follow confidentiality protocols and their priority is saving lives.
Prevention remains the best approach: use the minimum effective dose, avoid combining with other substances, and always have a sober person present who can recognize signs of distress and call for help.
Tolerance
| Full | Develops rapidly with repeated use |
| Half | 3 - 7 days |
| Zero | 1 - 2 weeks |
Cross-tolerances
Legal Status
The legal status of N-(2C)-fentanyl varies by jurisdiction and is subject to change. This information is provided for educational purposes and may not reflect the most current legislation.
General patterns: Many psychoactive substances are controlled under national and international drug control frameworks, including the United Nations Single Convention on Narcotic Drugs (1961), the Convention on Psychotropic Substances (1971), and country-specific legislation such as the US Controlled Substances Act, UK Misuse of Drugs Act, and EU Framework Decisions.
Research chemicals and analogues: Novel psychoactive substances may be captured by analogue laws (e.g., the US Federal Analogue Act) or blanket bans on substance classes (e.g., the UK Psychoactive Substances Act 2016), even if the specific compound is not individually scheduled.
Important note: Possessing, distributing, or manufacturing controlled substances carries serious legal consequences in most jurisdictions. Legal status is not a reliable indicator of a substance's safety profile — some highly dangerous substances are legal, while some with favorable safety profiles are strictly controlled.
Users are strongly encouraged to research the specific legal status of N-(2C)-fentanyl in their jurisdiction before any involvement with this substance.
Experience Reports (2)
Tips (2)
Keep a usage log for N-(2C)-fentanyl including dose, time, effects, and side effects. This helps you identify patterns and prevent problematic escalation.
Always start with a low dose of N-(2C)-fentanyl and work your way up. Individual sensitivity varies, and you cannot undo a dose once taken.
See Also
References (2)
- N-(2C)-fentanyl - TripSit Factsheet
TripSit factsheet for N-(2C)-fentanyl
tripsit - N-(2C)-fentanyl - Wikipedia
Wikipedia article on N-(2C)-fentanyl
wikipedia