Phenibut Stats - Substance Search

Receptor Profile

Receptor Actions

Agonists

GABA-B receptor agonist (full)

GABA-A receptor agonist (at higher doses)

Other

Voltage-gated calcium channel alpha-2-delta subunit ligand

History & Culture

1960s–1974

Phenibut was synthesized during the 1960s at the Department of Organic Chemistry at the Al Gertsen Leningrad Pedagogical Institute under the supervision of Professor V. V. Perekalin. Following its development, the compound was researched for potential applications in treating various conditions including anxiety, depression, post-traumatic stress disorder, insomnia, and general weakness or asthenia. Early research indicated that while phenibut shared certain properties with traditional sedatives, it produced less impairment and fewer "narcotic-like" effects in animal studies. The compound was initially introduced under the brand name Citrocard during the late 1960s to early 1970s. On December 18, 1974, phenibut was officially added to the State Drug Register under Order No. 1126 by the USSR's Ministry of Public Health, establishing it as an approved neuropsychotropic medication.

1975–present

Phenibut gained notable recognition for its inclusion in Soviet space program protocols. According to Neumyvakin (1978), the substance was available to Russian cosmonauts during the Soyuz-19 mission in 1975. The compound has since been cited as a mandated component of cosmonaut medical kits, though the precise extent of its utilization throughout the broader Soviet and Russian space programs remains unclear.

2000s–present

While phenibut has maintained continuous pharmaceutical availability in Russia since its initial release, the substance has seen minimal expansion into medical settings beyond Russian borders and remains unapproved for clinical use in most other countries. However, beginning in the 2000s and accelerating through the 2010s, phenibut became widely accessible internationally through the nutritional supplement industry, marketed and sold without prescription in many regions where it lacks pharmaceutical approval.

Subjective Effects

In comparison to other commonly used GABAgenic depressants such as alcohol or benzodiazepines, this compound is significantly longer lasting, more euphoric and more recreational.

Physical

Stimulation and Sedation: At lower doses, phenibut has a mild physical and mental stimulation effect, encouraging movement, wakefulness, and productivity. At higher doses, however, it becomes physically sedating, encouraging sleep and lethargy. Sleeping after dosing a small amount results in a deep, restful sleep which can leave the user feeling refreshed and alert upon waking.
Respiratory depression
Nausea: Phenibut can induce mild to extreme nausea depending greatly on dose and tolerance. It usually manifests roughly 5 hours after the initial dose and generally involves waves of nausea accompanied by excessive sweating and vomiting.
Increased perspiration
Motor control loss
Stomach cramps
Dizziness
Dehydration: Dehydration is reported to occur from regular multi-day usage or overdoses.
Headaches: Moderate to high doses can induce a mild headache many hours after dosing.
Physical euphoria
Muscle cramps: Muscle cramps and joint pain are sometimes accompanied at high doses.
Difficulty urinating: This effect generally only occurs after frequent usage.
Increased blood pressure
Temperature regulation loss
Appetite enhancement

Cognitive

Empathy, love and sociability enhancement: Unlike alcohol which merely increases sociability through disinhibition, phenibut presents strong entactogenic effects which, although much weaker than that of traditional entactogens such as MDMA, are still prominent and well-defined even at light doses.
Disinhibition
Information processing suppression: High doses will usually induce a state of mild stupor and confusion.
Thought deceleration
Cognitive euphoria
Motivation enhancement
Anxiety suppression
Depression: A low mood can be experienced as an after-effect of high or frequent dosing.
Amnesia

Forked from Subjective Effect Documentation by Josie Kins, July 2016. Via dose.wiki (CC0).

Toxicity

PsychonautWiki

Phenibut has a low toxicity relative to dose. However, it is potentially lethal when mixed with depressants like alcohol, benzodiazepines or opioids. Phenibut hydrochloride is highly caustic and in sensitive users can cause intestinal discomfort and diarrhea with some lower digestive tract bleeding. Due to the extremely long come up period relative to other substances, some users may experience an urge to redose out of the belief that it is weak or not working. This should be avoided to prevent overdose.

Addiction & dependence

Phenibut is moderately physically and psychologically addictive, although this usually only occurs with heavy abuse of the substance. Tolerance will develop to the sedative-hypnotic effects within a couple of days of continuous use.

Duration Timeline

Bluelight

Onset Comeup Peak Offset After Effects

Oral

1.5-3 hours

3-4 hours

4-6 hours

6-24 hours

Total: 4-10 hours

Rectal

30-60 minutes hours

1-3 hours

1-24 hours

Total: 4-10 hours

Community Effects

TripSit

Negative

anxiety insomnia psychosis

Tolerance & Pharmacokinetics

drugs.wiki

No tolerance chart. Our decay curves for these drugs were estimates, and a curve can make tolerance look longer-lasting than it is, which is the dangerous direction.

How fast tolerance to these drugs fades after a break has not been measured well enough to draw, so don't count on a dose you used to take still being safe: after time off, start with a much smaller amount and don't use alone. Mixing sedatives with each other, with alcohol or with opioids sharply raises the risk of a fatal overdose. If you've been using regularly, don't stop suddenly: withdrawal from benzodiazepines, alcohol or GHB/GBL can cause seizures or delirium, so get medical help to cut down gradually. Phenibut withdrawal after regular use has put people in hospital, where it is treated with the drugs used for benzodiazepine and alcohol withdrawal.

Sources: FRANK: benzodiazepines · Alcohol and Drug Foundation: GHB · FDA 2020: benzodiazepine boxed warning · FDA 2019: gabapentinoids and breathing · NHS: alcohol use disorder · Penzak & Bulloch 2024

Cross-Tolerances

Alcohol

GHB

GBL

Gabapentin

Pregabalin

Experience Report Analysis

Erowid BlueLight

120 Reports

61 Single-substance

2004–2025 Date Range

104 With Age Data

21 Effects Detected

Demographics

Gender Distribution

Age Distribution

Reports Over Time

Effect Analysis

Erowid + Bluelight

Effects aggregated from 86 experience reports (61 single-substance Erowid + 25 Bluelight)

86 Reports

96 Effects Detected

32 Positive

49 Adverse

15 Neutral

Effect Sentiment Distribution

Confidence Distribution

Each bar is the share of reports mentioning the effect; its whisker, and the band on the rows below, is the 95% interval: where the share could plausibly be with other reports of the same kind.

Positive Effects 32

Sedation 43.0% 84%

Stimulation 40.7% 84%

Sociability Enhancement 32.0% 81%

Euphoria 31.4% 87%

Music Enhancement 26.7% 90%

Contentment 24.0% 85%

Hypersomnia 24.0% 81%

Peace 24.0% 85%

Joy 20.0% 81%

Empathy 15.1% 80%

Focus Enhancement 15.1% 82%

Thought Acceleration 12.0% 87%

Color Enhancement 9.3% 85%

Body High 8.1% 75%

Relaxation 8.0% 90%

Geometric Imagery 8.0% 90%

Libido Enhancement 8.0% 75%

Creativity Enhancement 8.0% 78%

Introspection 8.0% 85%

Bliss 8.0% 88%

Adverse Effects 49

Dizziness 24.0% 85%

Nausea 23.3% 86%

Confusion 16.3% 88%

Body Load 16.0% 84%

Focus Suppression 16.0% 79%

Insomnia 16.0% 81%

Motor Impairment 12.8% 80%

Thought Disorganization 12.0% 75%

Vomiting 12.0% 92%

Headache 11.6% 88%

Memory Suppression 9.3% 78%

Heaviness 8.0% 80%

Disinhibition 8.0% 80%

Panic 8.0% 95%

Ataxia 8.0% 85%

Metallic Taste 8.0% 95%

Increased Heart Rate 6.6% 70%

Sweating 5.8% 85%

Pain Enhancement 4.0% 75%

Grogginess 4.0% 80%

⚠ Respiratory Depression 4.0% 85%

⚠ Chest Pain 4.0% 80%

Show 27 more adverse effects

Dysphoria 4.0% 80%

Tension 4.0% 75%

Tremor 4.0% 75%

Guilt 4.0% 70%

Fear 4.0% 90%

Open-Eye Visuals 4.0% 90%

Visual Snow 4.0% 85%

Internal Auditory Hallucination 4.0% 80%

Thought Loops 4.0% 85%

Temporal Disorientation 4.0% 80%

Pareidolia 4.0% 75%

Tactile Hallucination 4.0% 85%

Muscle Pain 4.0% 90%

Amnesia 4.0% 80%

Visual Vibration 4.0% 85%

Field Narrowing 4.0% 80%

Entity Imagery 4.0% 85%

Delusion 4.0% 80%

Time Compression 4.0% 75%

Blurred Vision 4.0% 85%

Appetite Suppression 4.0% 80%

Taste Distortion 4.0% 75%

Social Anxiety 4.0% 80%

Paranoia 4.0% 70%

Emotional Suppression 4.0% 75%

Muscle Twitching 4.0% 85%

Tinnitus 4.0% 80%

Show 15 neutral or unclassified mentions

Hospital 18.0%

Thought Deceleration 16.0%

Auditory Effects 15.1%

Visual Distortions 11.6%

Dissociation 9.3%

Restlessness 8.0%

Closed-Eye Visuals 5.8%

Distractibility 4.0%

Emotional Release 4.0%

Emotional Change 4.0%

Field Widening 4.0%

Visual Trails 4.0%

Zooming 4.0%

Double Vision 4.0%

Pressure 4.0%

Also reported in combinations. In the 59 Phenibut reports where another drug was taken too, 5 (8.5%) mention hospital, emergency services or an overdose, 2 (3.4%) a seizure and 3 (5.1%) psychosis. In the 61 single-substance reports: 18.0%, 1.6% and 1.6%. These are not in the figures above: they cannot be put down to Phenibut alone, and a mention is not always something that happened to the writer.

Dosage Distribution

Dose distribution from experience reports, one dose per report (the first listed). Doses above Q3 + 3×IQR, far above what people typically take, are left out of the median and range and listed under each route: most are real heavy doses or overdoses, not mistakes.

Median: 2000.0 mg IQR: 950.0–2550.0 mg n=48

1 report gave a dose above the typical range (10,000 mg), so it is not in the figures above. Listing a dose here does not mean it is safe.

Show the report

10,000 mg · another drug taken too

Real-World Dose Distribution

Erowid

From 166 of 188 recorded dose entries: those that state a weight (mg, g or µg), in routes with at least five of them. Values above Q3 + 3×IQR, far above what people typically take, are left out; they can include real heavy doses and overdoses, not only mistakes.

Oral (n=155)

Median: 1250.0mg 25th: 775.0mg 75th: 2000.0mg 90th: 3000.0mg

Insufflated (n=6)

Median: 75.0mg 25th: 50.0mg 75th: 100.0mg 90th: 125.0mg

Common Combinations

Most co-occurring substances, as a share of all 120 reports filed under Phenibut; whiskers are 95% intervals

Form / Preparation

Most common forms and preparations, as a share of the 47 reports that give one; whiskers are 95% intervals

Body-Weight Dosing

Dose per kg of body weight, one dose per report (the first listed), from reports giving a weight of 30–250 kg. Doses above Q3 + 3×IQR, far above what people typically take, are left out of the median and range and listed under each route.

Median: 24.51 mg/kg IQR: 11.686–31.724 mg/kg n=47

1 report gave a dose above the typical range (125 mg/kg), so it is not in the figures above. Listing a dose here does not mean it is safe.