How Long Does The Effects Of Phenibut Last?

What Is Phenibut?

Phenibut is a popular diet supplement that is legal in most countries and available through the internet without a prescription. It has been used for many decades to reduce anxiety and insomnia. Testing of the long term effects of Phenibut are ongoing. With the growing demand for this dietary supplement, it may be made more available worldwide.

Phenibut is a dietary supplement used mainly to teat anxiety and insomnia. In pure form it is phenyl aminobutyric acid and works as a central nervous system depressant. It is derived from GABA (y-aminobutyric acid), a neurotransmitter that can cross the barrier between the blood and the brain. It works to calm the nervous system. Unlike pharmaceutical drugs such as tranquilizers, Phenibut also works as a nootropic. Nootropics or “smart drugs” enhance cognitive thinking. While the supplement works to calm nerves and relax an individual, it also increases the ability to think clearly and gives confidence to people who suffer from general anxiety, social anxiety, fears and stress.


Phenibut was first developed in the Union of Soviet Socialists Republic (USSR) in the 1960s. It was developed by Professor Vsevolod Perekalin at the A I Herzen Lenongrad Pedagogical Institute for cosmonauts. When cosmonauts traveled to outer space Phenibut was used to reduce their high levels of stress and anxiety. Because it lowers stress levels without causing the grogginess or fogged mind that tranquilizers cause, Phenibut was the perfect solution for cosmonauts to remain clear headed yet relaxed while attending to their highly stressful missions. It was used in the Appolo-Soyez mission of 1975 and remains a part of Russian cosmonaut medical kits during all space missions. Around that time, Phenibut became available to the public in the USSR and could be used for many purposes.

How To Use Phenibut?

Depending on the issues of the individual, Phenibut should be taken either during the day or at night. If a person is suffering from major anxiety or stress, Phenibut can be taken during the day. It usually takes effect within 1-2 hours of ingestion. If an individual has insomnia, the supplement can be taken within 1-2 hours of going to bed. It should work to relax the user and help him fall asleep and stay asleep to become well rested.

Phenibut is used to treat many conditions. It has been a popular dietary supplement in the Soviet Union and Russia since the mid-1970s. In Russia it is regularly used for a variety of reasons. It is most often used to relieve anxiety, stress, fear and insomnia. It is also used to treat post traumatic stress disorder, depression, stuttering and vestibular disorders (inner ear balance problems). It has been used to treat epilepsy, stuttering and as a recovery booster. It is used as a pre and post operative medication to relax the patient before and after surgery. It has been used to treat alcoholism and other miner drug addictions because it works much like alcohol in the system as it relaxes and releases inhibitions and anxiety but, unlike alcohol, it does not impair a person. It is not a narcotic and can help an alcoholic or miner drug user with his withdrawal symptoms.

How Long Does Phenibut Last?

The effects of Phenibut can usually be felt within one to two hours of ingestion. It typically remains active in the system for four to five hours and the effects can be felt. It can remain in the body for several days. When taken in higher doses, Phenibut’s effects will last longer and remain in the body for longer.

What Will I Feel Like When I Take Phenibut?

As stated above, Phenibut use will calm the central nervous system while increasing brain cognition. Users feel a variety of emotions. Depending upon when taken and the individual, Phenibut can relax someone so they are able to fall asleep easier and able to sleep better. For someone with severe anxiety, post traumatic stress disorder, general stress or even depression, the supplement can decrease those negative characteristics or disorders. Users most often experience a feeling of confidence, conviction and self-assurance.


Phenibut has shown to have many benefits. As a nervous system depressant it acts to relieve anxiety and can be used to treat insomnia. For anyone undergoing extreme episodes of stress, social anxiety or general uneasiness and jitteriness, Phenibut can be a welcome relief. Without impairing an individual as alcohol pharmaceuticals would, Phenibut is a dietary supplement that has the ability to calm the body’s nervous system while helping the user function with better brain cognition and help the user become more aware of his surroundings and able to function on a better level than while his distressful condition is in control of his ability to function. Although it has not been proven, Phenibut is believed to improve neurological function and continues to be tested to prove this theory.

Recommended Dosage

There is no clear cut answer to what the dose of this supplement is the best. As with other supplements or medications, it most often depends upon the individual. Size, age, health and the general effects of medication or supplements on the particular individual are all factors in what does is proper to take. Because tolerance can build up quickly with Phenibut use, it is recommended to begin by taking the dietary supplement in small doses spread out in time. The recommended dose to begin with is just 1 gm every two to three days. Unlike vitamins and other supplements that should be taken daily, it is best to take Phenibut sparingly. Because it acts in the body fairly quickly (within one to two hours of ingestion), it is possible to take it only during periods of high stress or major anxiety attacks. However, if it is taken for post traumatic stress disorder or other disorders including vestibular (inner ear balance issues) disorders or even treatment for alcohol or minor drug addiction, Phenibut may need to be taken regularly. Nevertheless, Phenibut should not be taken in high doses in a small amount of time because of the build of tolerance that can lead to addiction and eventual withdrawal symptoms.

Side Effects

As previously stated, side effects of Phenibut use include headaches, dry mouth and the build up of tolerance. Phenibut should not be taken with MAO inhibitors or epilepsy medication. It is important to follow the recommended dosage (1 gm every two to three days) to prevent negative side effects. Those who take it in high doses frequently are more likely to have negative consequences such as dependency.

Short-Term Effects

The only negative short term effects of Phenibut use are fairly minor. Some people experience headaches or dry mouth. This increases with the use of the supplement in higher dosage and frequent use. Because of tolerance build up, people using the supplement in high doses and high frequency may experience withdrawal symptoms when the supplement is abruptly stopped. If this is the case, Phenibut use should be gradually reduced and tapered off over a period of extended time.

Long-Term Effects

It is unclear what the long term effects of Phenibut use is on humans. It has been tested in laboratory animals and appears to have little, if any, long term health effects. The supplement has not been tested for long term results on humans but has been used safely in Russia for several decades. Long term use of heavy doses may have some effect on the kidneys and liver.


Phenibut acts as a neurotransmitter between the blood system and the brain and the results are a nervous system depressant. It generally relieves anxiety, stress and fear. It can make the user feel more confident and less inhibited. Most users of the supplement have a feeling of increased energy coupled with calm. As a nootropic or “smart drug”, Phenibut enhances brain cognition. Unlike tranquilizers that make the user drowsy or groggy while calming the nerves, Phenibut “wakens” the mind. Users will feel less fear and anxiety as their brain function is enhanced. They can think more clearly than normal and function on a higher level than when they were filled with inhibitions and fears. Users feel clear headed, intuitive and insightful. They are no longer controlled by their social anxieties, apprehension and uncertainty. The supplement calms restlessness, jitters and panic episodes. The effects of Phenibut are considered similar to those of tranquilizers or alcohol in that users are able to function with courage and less inhibitions. However, although a nervous system depressant, Phenibut helps the user think more clearly and feel and express innate brain cognition.


Research on Phenibut use in animals and humans continues today. Wide testing has been done in Russia over the years and more recently, testing and trials have been conducted in the United States and Europe. While much research is still being conduction, to date, there have been little negative side effects of Phenibut use. As stated above, those who take higher doses than recommended and take the supplement on a regular, perhaps everyday, routine, are more likely to experience negative side effects. Headaches and dry mouth are mild examples. Possible kidney and liver damage as well as addiction to the supplement and eventual withdrawal are the major long term damages found through research.

Safety Concerns

It is undetermined if Phenibut negatively effects the kidney or liver. Obviously taken in high doses for extended periods of time, there will be some build up of hepatotoxicity. Should there be a concern for kidney or liver damage, Phenibut use should be limited in use and physical and blood examinations should be done periodically.

Is Phenibut Legal?

Phenibut has been legal to purchase and use in Russia since the 1970s. It does not require a prescription and is legally sold in many countries worldwide. Although not sold in drugstores in the United States and Europe, Phenibut can legally be purchased through the internet.

Phenibut has been popularly used in Russia for many decades and has recently become popular throughout the world. Although extensive testing and clinical trials on humans is ongoing, it appears that if this dietary supplement is taken in small doses and limited frequency, it can be taken for many reasons to benefit users. Phenibut can be used as an anxiety or depression supplement. It can be used to treat insomnia. It may be helpful in the treatment of certain medical conditions. Overall, Phenibut seems to have short term benefits that weigh over any long term side effects. If someone is in an extreme state of stress, social anxiety, general severe anxiety or other tense and consistently fearful states, Phenibut can be an asset in relieving these debilitating conditions temporarily.


  1. Lynn
    , 2016-06-22

    I’m having surgery. How long does Phenibut stay in a person’s system? I take Phenibut for social anxiety a few times a week. About 300 mg – 900 mg on days I need it. Will it be out of my system 3 days before surgery? Thank you.

  2. Lynn
    , 2016-06-22

    I take phenibut for social anxiety and work out purposes. I take it about 3 times a week at 300-900 mg per day average. I’m having surgery. If I stop taking Phenibut 3 days before surgery will it be out of my system? I am in good shape and exercise 3 times a week for 45 mins each time.


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