Phenibut: What It Is, Effects, Dosages, Safety & Best Source

Phenibut, based on its recreational use in the Western world, can best be described as a nootropic “smart” compound that helps improve cognitive functions across a wide spectrum of uses. In Russia and many former Soviet countries, Fenibut is prescribed as an anti-anxiety and anti-depressive for over 50 years and has a well-documented history of use.

In the US, the FDA has not approved Phenibut as a drug, but it can be purchased for individual use from a variety of online stores. There is, however, sufficient cause for concern in terms of who to procure Fenibut from and the manner and duration of its use.

In this article, we will discuss the best option to procure and how to best use this compound to help maximize its beneficial impacts without buying impure products or going overboard during using Phenibut.

If you are just looking for a place to order high-quality Phenibut, we would recommend Swiss Chems Phenibut.

What is Phenibut?


Phenibut, whose chemical name is β-phenyl-γ-aminobutyric acid or phenyl-GABA, is a synthetic form of gamma-aminobutyric acid (GABA), which is one of the neurotransmitters present in the human brain.

This GABA-β agonist was developed in St. Petersburg within the Soviet Union in 1963. After being initially used by astronauts in the Soviet space program, the drug became widely used when it began to be used mainly to treat young patients with psychiatric imbalances. Phenibut started to to be used regularly in the mid-’70s. The brand names sold include Fenibut, Anvifen, Adrafinil, and Noofent.

Nowadays, it is prescribed in countries in the region, such as Russia, Ukraine, Belarus, Kazakhstan, and Latvia, as an anti-anxiety medication.

In Russia, the prestigious BMJ Case Reports find that Phenibut has been prescribed to patients suffering from a wide range of anxiety disorders and depression, including stuttering, irregular heartbeat, vestibular disorders, and post-traumatic stress syndrome (PTSD).

Through medical study, researchers have determined that using Phenibut in more than small doses can have multiple adverse side effects. Also, it can be addictive after a prolonged period of use. This is why other countries – including the US FDA – do not yet allow its use as a prescription drug.

There are vendors who will advertise and sell Phenibut as a “supplement”, which designation is not approved by the FDA either. The closest designation, therefore, is likely a synthetic compound that is a nootropic, but not a drug or supplement.

For anyone wanting to purchase Phenibut, it is important to restrict its use to small doses on a daily and weekly basis, and also ensure that you buy from vendors who maintain the highest quality standards when they manufacture and market their products. In a later section, we will mention some of the potential risks and recommend a reliable vendor for the compound.

How Phenibut Works

As described, Phenibut is a GABA analog that is believed to activate the GABA receptors in our brain and deliver a calming effect. One big difference between GABA and Phenibut is that the latter can enter the brain through our bloodstream, which GABA cannot.

Phenibut can also inhibit anxiety, being a CNS depressant. In low concentrations, Fenibutincreases the dopamine quantities in the brain, which produces a mild sense of euphoria while tamping down anxiety.

Due to its chemical actions, Phenibut can regulate overactive neural processing and therefore help people who habitually overthink and are very self-conscious. In small does, Fenibut can help people overcome nervousness or anxiety in social settings, producing a calm and relaxed feeling. Reducing negativity and sedation are also possible effects.

The Effects of Taking Phenibut

As described above, the principal benefits of Phenibut are well documented through use in Russia and other former Soviet countries. We can discover them through the conditions that the compound is normally prescribed to cure or prevent. Examples include:

  • Calming down nerves and helping those with anxiety disorders
  • Reducing depression and stress-related syndromes, including PTSD
  • Addressing irregular heartbeat and vestibular disorders
  • Reducing social anxiety
  • Helping those who suffer from tics or stutter
  • Treating alcoholism and alcohol withdrawal symptoms
  • Treating dizziness and motion sickness
  • Treatment of asthenia and Ménière’s disease
  • Calming patients prior to surgery or painful procedures

In addition to the above, other user-reported “benefits” have not been adequately researched or proven. These are typically not based on data from medical use but on feedback from casual users who buy the compound online. Some common ones include:

  • Improving concentration and mental focus, without the upper-end jitteriness of caffeine or the depressive effects of alcohol
  • As with other nootropics, help enhance the executive functions of the brain, including attention, memory, creativity, and/or motivation
  • Potential help with muscular development
  • Inducing a feeling of mild euphoria in small doses

One caution, as before, is the dosage and the period of use, which is when harmful side effects and/or addictive tendencies may creep in.

Phenibut Dosage Information

Phenibut is available in solution, powders, capsules, and tablets. It is ingested orally, though it could be delivered intravenously as well.

What dose to take depends on a number of factors, all related to the user:

  • Age
  • Body Weight
  • State of Health
  • Other Health-Related Conditions
  • Other medications (especially depressants) may be regularly used for either medicinal or recreational purposes.

Good data is not available based on recreational use in the Western world, so a lot of the “advice” you get (ranging from “use 600 to 700 mg per day”, or “use once a day only” to “the effects will wear off in 4-6 hours, so take three times a day”) is not strictly scientific.

Given that new users should use smaller doses and that the human body tends to become tolerant to Phenibut over time, the following rules of thumb could be sensible:

  • New users should stick to 200-250 mg a day
  • On no account should more than 1500 mg (1.5 gm) be ingested in a day
  • Ideally, try not to ingest Phenibut more than thrice a week.
  • If more frequent and in heavier than very small doses, once a day is probably the safest.

As we discuss next, there are various side effects that can be avoided with sensible and moderate use, but if you overstep normal bounds, there could be some bad repercussions.

Does Phenibut Cause Side Effects?

Phenibut is generally well tolerated with moderated use. Any side effects will typically show up if the proper dosages (both daily and weekly, as mentioned above) are not followed or if one prolongs the use of the compound beyond a certain period of time.

Why do we say this? The answer is simple – while the FDA does not allow Phenbut for medicinal purposes and will object to it being labeled a supplement in many cases, it is fundamentally different than many “supplements and vitamins” sold at online stores with dubious claims about their efficacy and safety.

Phenibut has been used in Russia and surrounding countries for over 50 years, so the limitations upon its use are well documented in many medical and scientific journals.

With that preamble, let’s come to the possible side effects from mis- or overuse, which can be daunting without proper precautions.

Possible Side Effects

Side effects from Phenibut can be tabulated under different categories:

1. Side Effects from Regular Use

Even at moderate does, certain side effects may occur driven by the normal interactions within the central nervous system and the depressive effect Phenibut has.

Possible effects include sedation, somnolence, dizziness, headaches and (paradoxically) agitation and anxiety on the one hand, as well as nausea, allergic reactions and irritability on the other. These impacts can be more pronounced for certain people, especially if they (say) ingest a full dose on an empty stomach. This is why people should refrain from operating heavy machinery or otherwise undertaking dangerous tasks.

2. Side Effects from Heavy Doses

If taken in heavy doses, Phenibut can cause loss of motor coordination, imbalance and even hangovers. Stories of people failing sobriety tests while “under the influence” are not uncommon. With prolonged overdoses, the risk of eosinophilia and fatty liver disease increases.

3. Effects of Overdoses

An overdose of Phenibut can exacerbate many of the symptoms outlined above, causing drowsiness, severe nausea and vomiting, lowered blood pressure and eosinophilia. In addition to lethargy and somnolence, there have been reported instances of delirium, lack of responsiveness, and even unconsciousness and seizures. There have been fatalities as well.

In extreme cases, pronounced fatty liver degeneration and renal impairment can occur.

There is no standard antidote for Phenibut overdoses. Doctors will try to induce vomiting, use activated charcoal or gastric leverage or resort to symptom based treatments.

4. Developing Dependency

While there is a low risk of dependency from occasional, low-dose recreational use, repeated use at higher doses will help users develop tolerance, which can then lead to dependency,

Withdrawal symptoms are common if Phenibut use is discontinued. They include insomnia, irritability, anger, hallucinations and severe rebound anxiety leading up to acute psychosis.

There is, luckily, a treatment for withdrawal symptoms, which is Baclofen.

5. Prolonging Effects from Other CNS Depressants

Phenibut should be used very carefully if the user is taking other sedatives, opioids, antipsychotics, anticonvulsants or even consuming alcohol in significant amounts. Fenibut use on top of such depressants will both exacerbate, and extend the duration, of the effects from the use of such drugs.

Where to Buy Phenibut

Let’s start with the question of whether or not Phenibut is legal in the US.

According to the Center for Disease Control (CDC), Fenibut is legal to possess (and therefore use) in the US, but it is not approved as a licensed drug by the FDA. Moreover, the FDA has objected to vendors describing  Phenibut as a “supplement” on multiple occasions.

There are many online vendors who seem to be selling Fenibut. But this is where you must exercise due caution. A significant number of vendors may be selling you poor quality formulations, if they are not out to scam you outright.

Not only can “possessing and using” even properly formulated Phenibut cause you problems if you do not get the dosage or the period of use properly calibrated, but there is also a significant chance that you may get bad formulations – either deliberate or due to poor quality control – from most vendors. This can compound both the side effects and the possibility of getting addicted if harmful impurities are mixed in.

A noted psychiatrist from the University of Michigan, Edward Jouney, expressed his serious reservations about quality control. He reports calling representatives of several manufacturers, and not getting replies back from any of them.

In addition to the formulation and the actual dosage corresponding with what is reported on the label, there are also concerns about packaging. Poor packaging can lead to degradation during shipping or as the compound is stored at home over a long period of time.

Best Vendor for Phenibut on the Market – Our Recommendation

For something like Phenibut, the ONLY vendors you should trust are those that have established a strong reputation in the marketplace for rigorous third-party quality testing and inspection, and who freely make that data available to their customers.

In our opinion, by far the best option on the market is Science.Bio. As their webpage shows, ScienceBio sells Phenibut in different doses, bundles, and formulations. The six most common products are:

In this context, it makes sense to distinguish between the two main forms that Phenibut is sold in the market – Hydrochloride Salt (HCL) and Free Amino Acid (FAA). Phenibut HCL is produced by letting the FAA form react with hydrochloric acid.

Phenibut Explained

HCL vs. FAA Phenibut

The HCL form is more commonly available in the market. There are multiple reasons for it:

  • Phenibut HCL salt has a dipolar ion composition, which means that it possesses both a negative and a positive ionic (electrical) charge. Many believe that this enhances the nootropic properties. The FAA form does not have a dipolar ion charge.
  • There is also a commercial reason for Phenibut HCL dominating the market in most countries. As the compound became more popular, it was found that HCL salt was the most convenient form to bulk produce Phenibut and keep costs down.

Even if the superior effects of the HCL form have not been fully documented in the West, it is telling that from its inception, including its use in the Russian space program, Phenibut HCL has been significantly more prevalent in the market.

Other considerations may be tied to intake:

  • Phenibut HCL has a slightly bitter and sour taste when dissolved with water, but its not severe and can be counteracted by using a liquid medium such as citrus juice. Another option is to take the HCL doses in capsule form.
  • Phenibut FAA, on the other hand, can be taken directly under the tongue, at which point it enters the bloodstream directly and can act faster than with HCL.

Why Science Bio?

Science Bio is reputed in the marketplace for their rigid adherence to third-party quality testing and their insistence on making the results public in general, as well as on a batch-by-batch basis. As a result, the desired levels of purity, and superior packaging to prevent contamination or degradation are both assured.

As an example, let’s review how Science Bio manufactures and packages powders and liquid solutions for sale. To start with, each of their products has publicly viewable batch and lot coded reports, so you can feel safe that they are interested in (a) maintaining quality standards, and (b) being fully transparent about the same.

Table 1 below lists some of the other appealing characteristics side by side.

Table 1: Science Bio Product Quality, Packaging, and Convenience



Ensures purity by avoiding adulterants, excipients and/or flow agents

Below 10% variation in concentration

Tamper-proof seals to guarantee safe transport

Tamper-proof seals to guarantee safe transport, packaging to ensure minimal evaporation in storage

UV resistant PET single-wall jar to prevent degradation

UV resistant glass bottling to prevent degradation

Sold at slightly over the advertised weight to compensate for loss through adhesion

Convenient measurement with 1 ml pipette

All said and done, it’s hard to beat the high standard of care exhibited by Science Bio. is also known to have sarms for sale but also RU58841.

Typically, any order is fulfilled in a day.

Frequently Asked Questions about Phenibut

Following are three FAQs that often pop up from those who are considering this nootropic.

What’s Phenibut’s Half Life?

Scientists have calculated that Phenibut’s half-life within the human body is between 5 to 5.5 hours, though it varies based on the specific user.

How Long Does It Take for Phenibut to Kick In?

The typical time period after which you will feel the effects of Phenibut is 75-90 minutes, but this depends on how full you are otherwise. On a completely empty stomach, it can kick in half that time, whereas with a completely full stomach, it could take more than double the standard time.

As discussed before, Phenibut FAA will tend to kick in quicker than the HCL versions, since it travels directly into the bloodstream when taken sublingually.

How Long Does Phenibut Last?

Phenibut can linger in your body for up to a full day. Given that there are potential harmful side effects and some chance of addiction, think carefully if you feel like ingesting more than one standard dose a day.


While Phenibut cannot be prescribed, and some researchers have posited that it could have the types of side effects and addictive traits that (say) Xanax does, there is plenty to like about this “smart” nootropic.

First, there is a long, documented history of benefits and appropriate uses based on medical data from 50 years of use in Russia and other countries. Second, the side effects and potential for getting addicted are also well-researched.

All in all, if a new user spends some time researching Phenibut, they should be easily able to discover the whys, as well as the dos and don’ts. Applying adequate caution and listening to your body when taking any foreign substance should be part of any regimen.

Visit Science Bio today to learn more about Phenibut.

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