5-APB (5-(2-aminopropyl)benzofuran), also known by the street name "Benzofury," is a synthetic entactogen and stimulant belonging to the substituted benzofuran and substituted amphetamine chemical classes. It is structurally analogous to MDMA, with the methylenedioxy ring replaced by a benzofuran ring system, and is considered one of the more pharmacologically complex compounds in the novel psychoactive substance landscape. Users report an experience that blends empathogenic warmth, emotional openness, and mild psychedelic character — generally compared to a longer-lasting MDMA with gentler stimulation and more pronounced serotonergic depth.
5-APB emerged prominently in UK and European markets around 2010–2012 as part of the "legal high" wave. Its activity profile — triple monoamine reuptake inhibition combined with releasing-agent activity and direct 5-HT2A/5-HT2B agonism — produces effects qualitatively distinct from pure stimulants. Users describe pronounced emotional empathy, enhanced introspection, mild visual enhancement, and warm physical sensations with a softer comedown than MDMA. Community experience strongly emphasizes that the extended duration (6–9 hours) makes timing and planning important, and that the 5-HT2B agonism raises cardiac concerns with frequent use analogous to those documented for MDA and MDMA.
Neurotoxicity concerns parallel those of MDA — the unfluorinated benzofuran structure may expose the serotonin system to oxidative metabolites with repeated heavy use. While controlled studies on 5-APB neurotoxicity in humans are absent, the harm-reduction consensus urges infrequent use, adequate nutrition, and antioxidant preloading.
Safety at a Glance
High Risk- Test Your Substance
- Threshold: 40–60 mg | Common: 60–100 mg | Strong: 100–130 mg
- Toxicity: Acute Toxicity 5-APB's acute toxicity profile has not been formally characterized in humans. Based on its pharmacolog...
- Dangerous with: 25x-NBOH, 25x-NBOMe, Atropa belladonna, Datura, MDMA (+3 more)
- Overdose risk: Stimulant overdose from 5-APB is a medical emergency primarily involving cardiovascular and neuro...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Dosage
oral
Duration
oral
Total: 5 hrs – 8 hrsHow It Feels
The onset of 5-APB is slow and patient. An hour or more may pass after ingestion before the first signs appear: a gradual warming in the chest, a subtle softening of the edges between self and surroundings, and a dawning sense that emotional experience is becoming richer and more available. The slow build can be deceptive; those accustomed to faster-acting entactogens may be tempted to redose, a decision that the compound's long duration makes risky.
As the effects develop over the following one to two hours, 5-APB reveals a deeply empathogenic character. Emotional warmth expands steadily, filling conversations and silences alike with a quality of tender significance. Other people seem luminous in their humanity, and the desire to connect, to share, to understand feels genuine and important rather than chemically coerced. Touch becomes exquisitely pleasurable, and music acquires an emotional depth that can bring tears without warning. The body feels warm and heavy, grounded rather than energized. Unlike MDMA, which drives the user outward into activity, 5-APB tends to draw them inward, inviting contemplation and intimate connection rather than dancing and movement.
At the peak, three to four hours in, the empathogenic effects are at their fullest. There may be mild visual changes: enhanced color saturation, a slight waviness in the peripheral vision, a dreamlike quality to the light. The cognitive headspace is soft and introspective, less analytical than MDMA and more emotionally immersive. The jaw clenches, pupils dilate, and body temperature rises, but the physical side effects feel secondary to the emotional landscape. There is a quality of deep contentment and presence, a sense that this moment, this conversation, this piece of music is exactly where you need to be.
The decline of 5-APB is as gradual as its onset, unfolding over three to four hours as the empathogenic warmth slowly recedes. The long tail means the total experience can span six to ten hours, far longer than MDMA. The comedown is moderate, carrying the familiar serotonergic weight of lowered mood and emotional flatness in the following day or two. The body is tired, appetite is slow to return, and sleep may be shallow. But the memories of emotional connection formed during the peak tend to persist with unusual clarity, often described as among the warmest and most genuine of any empathogenic experience.
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(15)
- Abnormal heartbeat— Abnormal heartbeat (arrhythmia) is any deviation from the heart's normal rhythm — including beats th...
- Appetite suppression— A distinct decrease in hunger and desire to eat, ranging from reduced interest in food to complete d...
- Body load— A diffuse, heavy physical discomfort involving tension, pressure, and malaise in the torso and limbs...
- Dehydration— A state of insufficient bodily hydration manifesting as persistent thirst, dry mouth, and physical d...
- Increased blood pressure— Increased blood pressure (hypertension) is an elevation of arterial pressure above the normal 120/80...
- Increased heart rate— A noticeable acceleration of heartbeat that can range from a subtle awareness of one's pulse to a fo...
- Nausea— An uncomfortable sensation of queasiness and stomach discomfort that may or may not lead to vomiting...
- 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...
- Stimulation— A state of heightened physical and mental energy characterized by increased wakefulness, elevated mo...
- Teeth chattering— Teeth chattering is an involuntary, rhythmic movement of the jaw that produces rapid clicking or cha...
- Teeth grinding— An involuntary clenching and rhythmic grinding of the jaw muscles, known clinically as bruxism, that...
- Temperature regulation disruption— Impaired thermoregulation causing unpredictable fluctuations between feeling hot and cold, with risk...
- Temporary erectile dysfunction— Temporary erectile dysfunction is the substance-induced inability to achieve or sustain a penile ere...
- Vasoconstriction— A narrowing of blood vessels throughout the body that produces sensations of cold extremities, tingl...
Cognitive & Perceptual Effects
Visual(1)
- Peripheral vision changes— Alterations in side vision ranging from enhanced peripheral awareness to tunnel vision, with charact...
Cognitive(17)
- Analysis enhancement— A perceived improvement in one's ability to logically deconstruct concepts, recognize patterns, and ...
- Anxiety— Intense feelings of apprehension, worry, and dread that can range from a subtle background unease to...
- Cognitive euphoria— A cognitive and emotional state of intense well-being, elation, happiness, and joy that manifests as...
- Cognitive fatigue— Mental exhaustion and difficulty sustaining thought after intense cognitive experiences, common duri...
- Compulsive redosing— An overwhelming, difficult-to-resist urge to continuously take more of a substance in order to maint...
- Depression— A persistent state of low mood, emotional numbness, hopelessness, and diminished interest or pleasur...
- Empathy enhancement— A state of intensified compassion and emotional openness in which one feels deeply connected to othe...
- Focus enhancement— An enhanced ability to direct and sustain attention on a single task or stimulus with unusual clarit...
- Introspection— An enhanced state of self-reflective awareness in which one feels drawn to examine their own thought...
- Irritability— Irritability is a sustained state of emotional reactivity in which the threshold for annoyance, frus...
- Memory enhancement— Memory enhancement is a state of improved mnemonic function in which past memories become unusually ...
- Motivation enhancement— A heightened sense of drive, ambition, and willingness to accomplish tasks, making productive effort...
- Motivation suppression— Motivation suppression is a state of diminished drive and willingness to engage in goal-directed beh...
- Paranoia— Irrational suspicion and belief that others are watching, plotting against, or intending harm toward...
- Thought acceleration— The experience of thoughts occurring at a dramatically increased rate, as if the mind has been shift...
- Thought deceleration— The experience of thoughts occurring at a markedly reduced pace, as if the mind has been placed into...
- Wakefulness— An increased ability to stay awake and alert without the desire to sleep. Distinct from stimulation ...
Pharmacology
Mechanism of Action
5-APB is a triple monoamine reuptake inhibitor (TMRI) and suspected releasing agent for serotonin, dopamine, and norepinephrine. Like MDMA, the predominant monoamine action is serotonergic, with substantial norepinephrine and more modest dopamine activity. This monoamine release cascade is responsible for the empathogenic warmth, emotional openness, and mild stimulant character.
Critically, 5-APB is also a direct agonist at 5-HT2A and5-HT2B receptors. The 5-HT2A agonism contributes mild psychedelic enhancement to the experience — visual brightening, increased pattern recognition, and introspective depth that distinguishes it from MDMA. The 5-HT2B agonism is a safety concern: chronic activation of cardiac 5-HT2B receptors is associated with valvular heart disease, as documented with MDMA, MDA, and serotonergic appetite suppressants such as fenfluramine.
Pharmacokinetics
5-APB is active orally at doses of 60–120 mg. Onset begins 45–90 minutes after ingestion, with peak effects at 2–4 hours and a total duration of 6–9 hours. The extended duration relative to MDMA reflects slower hepatic metabolism via the cytochrome P450 system. Active metabolites including 5-hydroxybenzofuran derivatives may contribute to pharmacological activity and oxidative metabolite generation. Redosing substantially extends duration and increases neurotoxic exposure without proportionally increasing desired effects.
Receptor Profile Summary
- SERT/NET/DAT — reuptake inhibition and likely release; serotonin predominates
- 5-HT2A — direct partial agonism; contributes psychedelic/empathogenic depth
- 5-HT2B — direct agonism; cardiac safety concern with repeated use
- α1/β-adrenergic — cardiovascular stimulation, vasoconstriction
Tolerance
Rapid serotonergic tolerance develops. Cross-tolerance with MDMA and other serotonergic entactogens is expected. A minimum of 4–6 weeks between sessions is recommended by the harm-reduction community to allow receptor recovery and reduce neurotoxic risk.
Detection Methods
Standard Drug Panel Inclusion
5-APB (5-(2-Aminopropyl)benzofuran) is a benzofuran-class entactogen that is not detected on standard 5-panel or 10-panel immunoassay drug screens. Some MDMA/amphetamine immunoassays may show partial cross-reactivity due to the aminopropyl side chain, but this varies by manufacturer and cannot be relied upon. Extended panels do not typically include benzofuran compounds.
Urine Detection
5-APB (5-(2-Aminopropyl)benzofuran) can be detected in urine for approximately 2 to 4 days after use. Metabolism involves hepatic oxidation, O-dealkylation, and conjugation. The metabolic pathway has some overlap with MDMA metabolism due to the structural analogy, but the benzofuran ring system produces distinct metabolites. Standard immunoassay screens are unreliable for detecting benzofuran compounds.
Blood and Saliva Detection
Blood detection windows for 5-APB (5-(2-Aminopropyl)benzofuran) are approximately 12 to 48 hours. Oral fluid detection is possible for 24 to 48 hours. These modalities are used primarily in emergency medicine and forensic toxicology settings rather than routine drug testing.
Hair Follicle Detection
Hair follicle testing for 5-APB (5-(2-Aminopropyl)benzofuran) requires specialized LC-MS/MS analysis and is not included in standard commercial hair testing panels. Detection in hair is possible for up to 90 days with appropriate analytical methods and reference standards.
Confirmatory Testing
LC-MS/MS is the gold standard for confirming the presence of 5-APB (5-(2-Aminopropyl)benzofuran). This method can distinguish benzofuran compounds from MDMA, MDA, and other entactogens based on molecular weight, fragmentation patterns, and retention time. GC-MS is also effective. Reference standards are essential for positive identification.
Reagent Testing
Marquis reagent typically produces a dark purple to black color with 5-APB (5-(2-Aminopropyl)benzofuran), similar to the reaction seen with MDMA and MDA (due to the oxygen-containing ring system). Mecke reagent produces a blue-green to dark blue reaction. Simon's reagent helps differentiate primary amines (5-APB, 6-APDB: negative) from secondary amines (5-MAPB: positive). Mandelin may show an orange-brown color. The combination of reagent responses can narrow identification but cannot conclusively distinguish benzofurans from methylenedioxy compounds.
Interactions
| Substance | Status | Note |
|---|---|---|
| 25x-NBOH | Dangerous | — |
| 25x-NBOMe | Dangerous | — |
| Atropa belladonna | Dangerous | Extreme cardiovascular strain from anticholinergic and stimulant effects combined |
| Datura | Dangerous | Extreme cardiovascular strain from anticholinergic and stimulant effects combined |
| Diphenhydramine | Dangerous | Extreme cardiovascular strain from anticholinergic and stimulant effects combined |
| Harmala alkaloid | Dangerous | Risk of hypertensive crisis and serotonin syndrome; potentially fatal combination |
| Peganum harmala | Dangerous | Risk of hypertensive crisis and serotonin syndrome; potentially fatal combination |
| MDMA | Unsafe | — |
| 1,3-Butanediol | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 25E-NBOH | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 2C-T | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 2C-T-2 | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 2C-T-21 | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| Alcohol | Uncertain | — |
| Dissociatives | Uncertain | — |
History
Origins and Chemical Development
5-APB was first synthesized in the context of designer drug research as a structural analog of MDMA exploring the pharmacological consequences of replacing the 3,4-methylenedioxy ring with a benzofuran scaffold. The structural modification shifts the compound from the phenethylamine to the benzofuran class while retaining the core 2-aminopropyl side chain responsible for monoamine transporter interaction.
Rise as a Novel Psychoactive Substance
5-APB achieved its widest market presence in the United Kingdom during 2010–2012, sold openly under the brand name "Benzofury" while exploiting temporary gaps in analogue legislation. It became one of the most commercially successful "legal highs" of that era, with a distinct following among MDMA users seeking a legally available alternative with a more introspective, empathogenic character.
Legal Control
The UK Psychoactive Substances Act 2016 effectively banned 5-APB along with the entire class of novel psychoactive substances. It had previously been classified as a Class B drug in the UK in 2012 via a temporary class drug order. Many European jurisdictions followed with their own scheduling actions. In the United States, 5-APB is subject to the Federal Analogue Act as an analogue of MDMA, a Schedule I controlled substance, making its sale for human consumption a federal offense. It remains unscheduled in some jurisdictions but is legally ambiguous in most.
Research Status
5-APB has not been formally studied in human clinical trials. Its pharmacological characterization comes from in vitro receptor binding studies and user-reported experience. The absence of controlled safety data is a core harm-reduction concern.
Harm Reduction
Test Your Substance
Vendor substitution and adulteration with cheaper compounds is a documented hazard. Use a Marquis reagent (orange→black for 5-APB) and optionally an Ehrlich reagent to confirm the presence of a substituted amphetamine scaffold. Fentanyl test strips are a prudent secondary precaution given the current supply landscape.
Dose Guidelines
- Threshold: 40–60 mg |Common: 60–100 mg |Strong: 100–130 mg
- Begin at the low end of the range, especially for first experiences. The 5-HT2A agonism means the onset can feel delayed relative to stimulants — wait at least 90–120 minutes before considering supplementation.
- Avoid redosing. The extended baseline duration means a redose typically only amplifies the undesirable aspects (cardiovascular strain, jaw clenching, stimulant body load) without meaningfully enhancing the empathogenic peak.
Frequency and Neurotoxicity Risk Reduction
The harm-reduction consensus is a minimum of 4–6 weeks between uses, ideally 2–3 months. The "three-month rule" used for MDMA is applicable here given comparable serotonergic mechanisms.
Pre-loading with antioxidants (alpha-lipoic acid, vitamin C, NAC) 1–2 hours before dosing and continuing for 24 hours post-experience has community support for reducing oxidative metabolite damage, though controlled human evidence is lacking.
Managing Physical Strain
- Maintain moderate hydration — approximately 250–500 mL per hour in warm or active settings; use electrolyte drinks rather than plain water
- Avoid hot, crowded environments; prioritize temperature regulation
- Avoid vigorous physical activity at peak dosing
- Magnesium supplementation (glycinate or L-threonate) the evening before may reduce jaw clenching (bruxism)
Dangerous Combinations
- MAOIs — fatal serotonin syndrome risk
- Tramadol, linezolid, methylene blue — serotonin syndrome risk
- Stimulants — compounded cardiovascular stress
- Alcohol — masked dehydration, increased cardiotoxic risk
- Lithium — unpredictable seizure and CNS risk
Toxicity & Safety
Acute Toxicity
5-APB's acute toxicity profile has not been formally characterized in humans. Based on its pharmacological similarity to MDMA and MDA, the expected acute risks include hyperthermia, hyponatremia (water intoxication), serotonin syndrome, and cardiovascular strain. Hyperthermia is the most life-threatening acute risk — elevated serotonin, dopamine, and norepinephrine simultaneously impair thermoregulation, particularly in warm environments with physical activity.
Cardiovascular Effects
Sympathomimetic stimulation produces elevated heart rate, increased blood pressure, and vasoconstriction. Individuals with pre-existing cardiac conditions, hypertension, or arrhythmias face amplified risk. The 5-HT2B agonism raises additional long-term concern: chronic, repeated dosing may contribute to cardiac fibrosis and valvular abnormalities by the same mechanism documented for other serotonergic drugs.
Serotonin Syndrome
Combination with MAOIs, SSRIs, SNRIs, or other serotonergic compounds creates risk of serotonin syndrome — a potentially life-threatening condition presenting with hyperthermia, clonus, altered mental status, and autonomic instability. This is an absolute contraindication.
Neurotoxicity Concerns
The benzofuran analog structure of 5-APB is metabolized to reactive quinone intermediates that may produce oxidative damage to serotonergic axon terminals — analogous to MDA's established neurotoxic potential in animal models. Human neurotoxicity data are lacking, but the structural parallel is sufficient to prompt precaution. High doses, frequent use, hyperthermia, and dehydration all amplify this risk.
Hyponatremia
Excess water consumption to counteract dehydration or hyperthermia can produce dangerous hyponatremia (dilutional low sodium), particularly if combined with the SIADH-like effects of serotonin system activation. Electrolyte-containing sports drinks are preferable to plain water.
Drug Interactions
Addiction Potential
moderately addictive with a high potential for abuse
Overdose Information
Stimulant overdose from 5-APB is a medical emergency primarily involving cardiovascular and neurological toxicity.
Signs of overdose: Extremely rapid or irregular heartbeat, chest pain, severe headache, dangerously elevated body temperature, seizures, agitation progressing to psychosis, confusion, and loss of consciousness.
Emergency response:
- Call emergency services immediately
- Keep the person cool (remove excess clothing, apply cool water)
- If seizures occur, protect the head and clear the area of hard objects
- If the person loses consciousness, place in recovery position
- Do not give the person more stimulants, caffeine, or depressants unless directed by medical professionals
Prevention: Pre-measure doses. Avoid redosing. Stay hydrated (but don't overhydrate). Take breaks from physical activity. Monitor heart rate if possible. Have someone present who can recognize warning signs.
Dangerous Interactions
The combinations listed below may be life-threatening. Independent research should always be conducted to ensure safety when combining substances.
Extreme cardiovascular strain from anticholinergic and stimulant effects combined
Extreme cardiovascular strain from anticholinergic and stimulant effects combined
Extreme cardiovascular strain from anticholinergic and stimulant effects combined
Risk of hypertensive crisis and serotonin syndrome; potentially fatal combination
Risk of hypertensive crisis and serotonin syndrome; potentially fatal combination
Tolerance
| Full | develops with prolonged and repeated use |
| Half | 3 - 7 days |
| Zero | 1 - 2 weeks |
Cross-tolerances
Legal Status
Brazil: Possession, production and sale is illegal as it is listed on Portaria SVS/MS nº 344.
France: 5-APB is classified as a narcotic since May 9, 2018, alongside other substances derived from benzofuran.
Germany: 5-APB is controlled under Anlage II BtMG (Narcotics Act, Schedule II) as of July 17, 2013. It is illegal to manufacture, possess, import, export, buy, sell, procure or dispense it without a license.
Japan: 5-APB is a controlled substance in Japan effective September 16th, 2015.
The Netherlands:** 5-APB is currently legal, but it is part of a substance group that may be banned soon as part of a recently passed law on New Psychoactive Substances (NPS).
Switzerland: 5-APB is a controlled substance specifically named under Verzeichnis E.
United Kingdom: 5-APB is a Class B drug.
United States: 5-APB could be considered an analogue of MDA and therefore would be covered under the Federal Analogue Act if intended for human consumption.
Responsible use
Designer drug
Stimulant
MDA
5-APB (Wikipedia)
5-APB (Isomer Design)
Community
The Big and Dandy 5-APB Thread (Bluelight)
Greene, S. L. (2013). Benzofurans and benzodifurans. In Novel Psychoactive Substances (pp. 383-392). https://doi.org/10.1016/B978-0-12-415816-0.00016-X
Experience Reports (1)
Tips (6)
5-APB has significant serotonergic activity similar to MDMA. Space uses at least 6-8 weeks apart to allow serotonin system recovery. Supplement with 5-HTP (starting 24 hours after use, not before or during) and antioxidants.
Start low with 5-APB and wait for full onset before redosing. Stimulant redosing extends duration and side effects more than it extends euphoria, while adding cardiovascular strain. Set a firm limit before you start.
Standard reagent test kits have limited ability to distinguish between different benzofuran isomers (5-APB, 6-APB, 4-APB). A Marquis test will show a reaction but cannot confirm which specific isomer you have. Consider sending samples to a lab testing service for accurate identification.
5-APB succinate and HCl salt forms have different potency by weight. HCl requires roughly 70-100mg while succinate may need 100-140mg for equivalent effects. Always verify which salt form you have before dosing.
Avoid binge patterns with 5-APB. Sleep deprivation combined with stimulant use dramatically increases psychosis risk after 48+ hours awake. If you find yourself redosing to avoid the comedown, that is a major warning sign.
Stay hydrated while using 5-APB. Stimulants increase heart rate and body temperature while suppressing thirst signals. Sip water regularly, roughly 250-500ml per hour, more if dancing or in hot environments.
Further Reading
See Also
References (5)
- Amphetamine: new content for an old topic — Heal et al. Neuropsychopharmacology Reviews (2013)paper
- MDMA-assisted therapy for PTSD — Mithoefer et al. Psychopharmacology (2019)paper
- PubChem: 5-APB
PubChem compound page for 5-APB (CID: 9837232)
pubchem - 5-APB - TripSit Factsheet
TripSit factsheet for 5-APB
tripsit - 5-APB - Wikipedia
Wikipedia article on 5-APB
wikipedia