Phenibut is a synthetic substance, originally made to improve anxiety symptoms and cognitive function. It is not approved for medical use in most countries, including the US, but can be purchased online, where it is sold as a dietary supplement. Phenibut use carries a high risk of side effects, addiction, overdose, dependence, and withdrawal.
- Phenibut is a man-made substance that causes a range of effects, some of which may be desired or beneficial and others that may be harmful.
- In the US, phenibut is not approved as a medical drug. It is sold online as a dietary supplement, despite a warning issued by the FDA that this is not legal.
- Phenibut can cause serious adverse effects and risks of dependence, addiction, and overdose.
Understanding phenibut
Phenibut (beta-phenyl-gamma-aminobutyric acid) is a derivative of gamma-aminobutyric acid, working primarily on GABA receptors. It is structurally similar to several medications, including baclofen, gabapentin, and pregabalin. [1]
Phenibut is a synthetic substance made in the 1960s by the Soviet Union military. It was intended to be used to improve cognitive function and anxiety symptoms. To this day, in ex-Soviet countries, phenibut continues to be used clinically for these purposes, and in the treatment of other conditions, including insomnia, alcohol withdrawal, and post-traumatic stress disorder (PTSD).[2]
Phenibut is not approved for medical use in other countries. However, in recent years, it has been marketed internationally as a supplement to improve brain function and mood. Some use phenibut for this purpose, while others are reportedly using it recreationally, to manage withdrawal from or as a substitute for other substances such as benzodiazepines. [2]
However, the evidence for its beneficial purposes is unclear, with limited research and contradictory results between available studies. Furthermore, phenibut has been linked to significant risks, including addiction, overdose, tolerance and dependence development, and severe side effects. [2][3]
How and why do people use phenibut?
In the United States, phenibut can be bought online, where it is often falsely and illegally marketed as a dietary supplement. It is sold as a product that can improve: [2]
- Mood
- Focus
- Relaxation
- Restlessness
- Irritability
- Memory
- Learning
- Concentration
- Libido
Some people who buy phenibut use it for these purposes, often believing it to be a safe and natural product. Generally, people are unaware of its potential harm due to deceptive claims from companies supplying the drug, such as “relief of social anxiety” and “helps in making essential decisions”. [2]
However, some people use phenibut recreationally, for its euphoric effects or to enhance the effects of other substances. Reportedly, almost two-thirds of those who use phenibut take it concurrently with other substances. [4]
Is it safe? Phenibut risks and side effects
A major risk associated with phenibut use is its unregulated availability. Sold online as an unapproved substance, phenibut products can vary significantly in content and potency. This means that people using phenibut may be unaware of the dosage they use and might not understand the potential risks. [5]
Side effects
Possible side effects of phenibut include: [2][6]
- Drowsiness
- Fatigue
- Changes in heart rate
- Agitation
- Confusion
- Decreased consciousness
- Drop in body temperature
In some cases, severe effects can occur, including seizures, delirium, psychosis, and coma. Side effects can be dose-dependent and may be more severe in children and adolescents, or people with pre-existing health conditions. Phenibut can result in liver damage with long-term use. [2][4] Additionally, phenibut may interact dangerously with other substances, particularly alcohol, sedatives, and medications that slow brain activity, which can increase the risk of drowsiness, breathing problems, and overdose.
Dependence, tolerance, and addiction
Phenibut use can lead to the development of tolerance, dependence, and addiction. This risk is particularly high due to its rapid and short-lived effects, which can lead to repeated and regular use. [4]
Phenibut has a short half-life of around 5 hours, which means it can be entirely removed from the system within one day. The effects of phenibut in the brain last around six hours, although this can vary depending on age, dose, and administration method. As such, tolerance can develop quickly, resulting in the use of increased doses to achieve the same effect. [2][6]
Similarly, physical dependence can develop quickly, with some reports suggesting that it can occur within one week of repeated use. This can lead to withdrawal symptoms when use is stopped. [5]
As such, there is a high risk of addiction with phenibut use, particularly if it is used in increasing doses and for prolonged periods. Phenibut addiction can result in the need for hospitalization and urgent care due to its potentially dangerous effects and withdrawal symptoms. [2]
Interactions and overdose
Phenibut can impact people differently, and there can be a high risk of overdose. Reports show that children and teenagers may experience phenibut toxicity from doses much smaller than those seen in adult cases. [2] Phenibut overdose can cause: [2][4]
- Extreme sedation
- Extreme changes in heart rate
- Loss of consciousness
- Agitation
- Delirium
- Psychosis
- Drop in temperature (hypothermia)
- Seizures
Toxicity can occur after a single use or as a result of repeated use that leads to a buildup of the drug in the body. Overdose may be more likely if phenibut is combined with other substances, particularly central nervous system (CNS) depressants, such as alcohol, benzodiazepines, and opioids, resulting in a high risk of oversedation and respiratory depression. [2]
Drug interactions with phenibut are not currently known due to limited research, but it may interact with anxiolytics, antipsychotics, sedatives, opioids, anticonvulsants, and cannabinoids. [2]
There is currently no specific antidote for phenibut overdose. It requires supportive care, monitoring, and management of symptoms. With treatment, symptoms can resolve within hours or days, although some symptoms can continue for several weeks or months. [2][4]
Withdrawal symptoms and timeline
Phenibut withdrawal is common. Withdrawal symptoms can be severe, whether phenibut is used alone or alongside additional substances. Symptoms can emerge within two hours after the last dose, reach their most severe within three days, and may last for approximately four weeks. [1][3] Phenibut withdrawal symptoms can include: [1][2][5]
- Delirium
- Insomnia
- Anger
- Agitation
- Restlessness
- Shaking
- Palpitations
- Hallucinations
- Anxiety
- Catatonia
- Involuntary movements
One report shows that 95.7% of phenibut withdrawal cases required hospitalization or clinical care due to the severity of symptoms. [4] Tapering off phenibut slowly can reduce the risk of withdrawal. Medications can be used to help manage withdrawal symptoms, such as benzodiazepines, baclofen, or antipsychotics, although in some cases, symptoms do not improve with these treatments. [1][5]
Legal status and regulation
Phenibut continues to be used in ex-Soviet Union countries, including Russia, Belarus, Latvia, and Ukraine, where it is legal for medical use. In the US, European countries, and Australia, phenibut is not approved as a medical drug.
Is phenibut legal in the US?
Phenibut is technically legal to purchase in the US, where it can be bought online and is not regulated. It is often marketed as a dietary supplement, despite not meeting the definition of a dietary ingredient. [7]
The Food and Drug Administration (FDA) issued warnings in 2019, stating that phenibut cannot be legally sold as a dietary supplement. Since then, many companies have continued to sell phenibut online, either not labeling it as a dietary supplement or including it in products sold as dietary supplements without listing phenibut as an ingredient. As such, it continues to cause dangerous consequences for those who intentionally or unintentionally use it. [2][7]
Getting help and treatment options
Currently, there are no evidence-based treatment options for phenibut dependence and addiction. However, support from specialist substance use disorder services can be beneficial, providing safe and supported withdrawal, interventions to overcome addictive behaviors, and appropriate medications where required. [2]
A primary care physician can provide advice and referral to specialist services. Also, local rehab options can be explored on the Recovered Directory.
