Issac Thorne

Last Updated February 12, 2022

Need an explanation on how to take phenibut properly? You’re in the right place.

There has been an explosion in nootropic research in recent years, including researchers curious to learn more about phenibut. But to design an effective study, you need to ensure that your research subjects are ingesting phenibut properly.

Phenibut is a purported nootropic. It’s actually used in several countries as an anti-anxiety medication, as a sleep aid, and as a way to boost cognition.

But in the research space, we’ve noticed some confusion among researchers about the many types of phenibut, different dosing strategies, and various routes of ingestion.

We’re here to clear all that up for you. In this article, we’ll explain what phenibut is, potential side effects, how much phenibut to take, and more.

Let’s get to it.

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Disclaimer: contains information about products that are intended for laboratory and research use only, unless otherwise explicitly stated. This information, including any referenced scientific or clinical research, is made available for educational purposes only. makes every effort to ensure that any information it shares complies with national and international standards for clinical trial information and is committed to the timely disclosure of the design and results of all interventional clinical studies for innovative treatments publicly available or that may be made available. However, research is not considered conclusive. makes no claims that any products referenced can cure, treat or prevent any conditions, including any conditions referenced on its website or in print materials.

What Is Phenibut?

Before we talk about how best to administer phenibut, let’s talk a bit about what it is.

Phenibut is a psychotropic drug, which means it can alter mental state and mood [1]. It’s prescribed in several countries, like Russia, Ukraine, and Belarus, as medication for conditions including anxiety, post-traumatic stress disorder, insomnia, and even stuttering [1, 2].

The chemical makeup of phenibut is β‐phenyl‐γ‐aminobutyric acid HCl [1]. It works by mimicking a neurotransmitter, GABA [3, 4]. Neurotransmitters are chemicals that are produced in our nervous system. They are important because they bind to receptors to send chemical signals, helping our brain to control and regulate our bodies.

The role of GABA in the body

GABA stands for gamma-aminobutyric acid [5]. It is one of the body’s major inhibitory neurotransmitters, which means it reduces excitability of the body.

Think about it like a car: You want to turn the car on when you need it, but you need to turn the car off when you don’t need it. Some neurotransmitters bind to receptors on nervous system cells to turn on signals to different parts of the body. They do this, for example, when we sense a threat. Neurotransmitters and hormones get sent out to get our bodies ready for action.

GABA turns them off when we no longer need to be “activated.” GABA helps revert back to our resting state so that we’re not constantly stressed. It is involved in a bunch of processes that help to relax our bodies.

Phenibut Mimics GABA

Phenibut is a “GABA analogue” [5], which means that it is chemically very similar to GABA. It can bind to many of the same receptors that GABA does. More specifically, it acts as an agonist for the GABAB receptors. At high concentrations, it also acts as an agonist for the GABAA receptors.

Because it activates the same receptors as GABA, it has some of the same effects: it reduces neuronal stimulation and excitability [1]. That’s why phenibut is reported to have effects like relaxation and improved sleep. It’s a key to turning off the brain.

Phenibut also has a few other interesting potential effects. For example, at low levels, it seems to activate dopamine receptors in the brain [5]. Dopamine is another neurotransmitter. It’s associated with the pleasure centers of the brain. Research has found that users of phenibut report boosted mood and feelings of “euphoria” and these effects may be a result of upregulating dopamine.

Effects of Phenibut

So what are the purported benefits and clinical effects of phenibut? Well, the research suggests that there could be quite a few. As a prescription drug in several Eastern European countries, including Russia, phenibut is used to treat [1, 5, 6]:

  • Anxiety
  • Alcohol withdrawal
  • Depression
  • Insomnia and sleep disorders
  • Post-traumatic stress disorder
  • Stuttering
  • Vestibular disorders

Note that, in the United States, phenibut is an unapproved “New Drug” under the U.S. Federal Food, Drug, and Cosmetic Act (FD&C Act), and, as of this writing, has not been investigated or approved for any of the above uses.


Phenibut Side Effects and Safety

Is phenibut fine for your research subjects to use?

Yes, the clinical research that exists suggests that phenibut, at prudent doses, is well-tolerated by most people [1]. That’s why it has been licensed for use as a prescription medication in several countries [5].

But like pretty much any substance, there is a possibility of side effects [2]. Also, there can be some negative effects if it is taken in large quantities or with other substances that work on the GABA pathways. There is also a potential for phenibut dependence.

Finally, note that among exposures in which phenibut was the only drug or agent involved, there has been at least one death reported to a U.S. poison center [6].

Side effects of phenibut and allergies

Phenibut side effects are quite uncommon, but they can occur. Some of the side effects that have been reported include [1, 2]:

  • Drowsiness
  • Nausea
  • Irritability
  • Headache
  • Sedation

Sometimes, but less often, subjects using phenibut may experience:

  • Motor incoordination
  • Hangover-like symptoms
  • Loss of balance

It’s also possible to experience an allergic reaction to phenibut. This usually manifests as skin itching and rashes.

If your test subjects experience any of these side effects, ensure that they stop taking the phenibut and speak to their doctor.

How can these side effects be avoided in research subjects? Adopt a research protocol that ensures doses are low. See the next section for phenibut dosing protocols used in previous research.


While death appears to be rare in phenibut research [1, 7, 8], there has been at least one death that appears to have occurred as a result of taking phenibut [6]. Some of the other adverse effects from overdosing can include [7, 8, 9]:

  • Severe drowsiness
  • Nausea
  • Vomiting
  • Lowered blood pressure
  • Impairment of the kidneys
  • Fatty liver degeneration

We’ll go over possible dosing protocols below. Generally, however, existing research indicates that phenibut doses given to human subjects do not exceed:

  • 750 mg in a single dose
  • 2 g per day, in total

To maximize safety, ensure that your subjects stick to a reasonable dosing protocol. If your research dosing protocol stays below the levels listed above, you’ll be within the normal range of phenibut dosage in the current research literature [1].

Interaction Effects

Another consideration is to make sure phenibut isn’t mixed with other substances that could cause interaction effects [7].

Phenibut is a “depressant” meaning that it “depresses” or “slows down” the nervous system. So taking it with other nervous system depressants should be avoided. These include [8]:

  • Alcohol
  • Benzodiazepines
  • Anticonvulsant medications
  • Antipsychotic medications
  • Opioids
  • Sedatives
  • Anti-anxiety medications

If phenibut is combined with any of those, it could cause one or both substances to be more powerful or last longer.

Again, this is easy to avoid. Just ensure that your subjects don’t consume phenibut with any of the above substances.

Phenibut Dependence

Last, researchers should be aware of phenibut dependence [3, 4]. This occurs when phenibut is taken regularly and the body gets used to it to the point that it stops making its own GABA.

At that point, phenibut becomes required to maintain regular physical function. When phenibut dependence develops, reducing phenibut intake can cause unpleasant withdrawal effects [8].

Research subjects with a propensity for addiction are not good candidates for phenibut research. Also, make sure your subjects do not take it more than 1 or 2 times per week, and they should cycle off phenibut every once in a while.

If you ensure your research protocol is consistent with those precautions, you should reduce the risk that your subjects develop phenibut withdrawal symptoms.

How To Take Phenibut | Beginner’s Guide

How one takes phenibut depends on what kind of phenibut is being taken.

There are two different types of phenibut: phenibut FAA and phenibut HCL.

  • Phenibut FAA: This is phenibut just as a pure, free amino acid (FAA). It usually comes in a powder or a capsule. It’s a bit more expensive and it has a higher concentration of phenibut by weight. Generally, a lower dosage is needed when phenibut is taken in this form.
  • Phenibut HCL: This is phenibut that has been made into a salt with HCL. It comes as capsules or as crystals. It’s the more common form, usually a bit cheaper, and has a lower concentration of phenibut by weight. Generally, a higher dosage is needed when phenibut is taken in this form.

In both types, the phenibut itself is the exact same. It’s just mixed differently and so it should be taken differently.


Ways To Take Phenibut

There are four main ways that your test subjects can ingest phenibut.

  • Swallow phenibut capsules. How to take phenibut powder capsules? Your test subjects can swallow them with liquid or on their own. This works for both FAA and HCL.
  • Mix it with liquid and drink it. If your subjects have powder (FAA) or crystals (HCL), they can mix it in a liquid and drink it. Remember that the FAA doesn’t mix well, so it might be clumpy.
  • Sublingually. Your subjects can put phenibut FAA under the tongue and wait for it to dissolve. This doesn’t work with phenibut HCL.
  • Injection. Very few people use this method outside of a medical context. It’s not recommended for the vast majority of research purposes.

Make sure your test subjects take phenibut on an empty stomach. Also, have them refrain from eating for an hour afterward. This allows the body to properly ingest phenibut and leads to optimal results.

How To Take Phenibut FAA

Phenibut FAA generally comes as a capsule or a powder. Here’s how to take phenibut FAA:

  • Swallow the capsule. It takes a while for it to kick in—usually about 2 hours. Have your test subjects take it in the morning if you want to observe its effect on mood, or at night if you want to see its effect on sleep.
  • Mix powder with a drink. This doesn’t work super well, because it’s not ionic, so it doesn’t mix in water very well. It gets clumpy. Still, your test subjects can take it this way if they wish.
  • Sublingually. Your test subjects can put phenibut FAA under the tongue and wait for it to dissolve. It takes some time, and it doesn’t taste great…but it will work faster if your test subjects use this method.

It doesn’t work well with food, so consider advising your test subjects to avoid eating before taking it. Once they take it, it’s best to wait for an hour before eating.

How To Take Phenibut HCL

Here’s how to take phenibut HCL.

  • Dissolve it in a drink. Phenibut HCL is a chemical salt, so it dissolves easily in water and other beverages. This is one of the easiest ways to take it.
  • Swallow a capsule. This is another easy way to take it that’s also effective.

It’s not advised to use the sublingual method with phenibut HCL. It’s acidic, so it’ll be bad for the teeth. Also, because it’s acidic, the taste is really strong.

This is the easiest form of phenibut to take and is highly recommended for research purposes.

How Much Phenibut to Take?

How much phenibut your test subjects should consume depends on a few factors. These include, but are not limited to: the subject’s size, their age, what type they’re administering, and the desired effects.

We’ve synthesized dosing protocols listed in the research for someone starting out with phenibut research and who wants a low-risk way to observe its effects. Each of these possible protocols uses a lower phenibut dose than those used in other research studies [1]. Each is also within the dosing guidelines provided in the phenibut insert in countries where it’s sold as a prescription medication [7]:

For phenibut FAA, test subjects who are new to phenibut can start with:

  • 250mg to 350mg
  • split into 1 to 3 doses per day
  • Take on an empty stomach at least one hour before food

For phenibut HCL, beginners can start with:

  • 350mg to 500mg
  • split into 1 to 3 doses per day
  • Take on an empty stomach at least one hour before food

By following these phenibut dosing protocols, you'll be able to study the potential social and creative benefits of phenibut while minimizing risks to your test subjects.

How Long Does It Take for Phenibut to Kick In?

How long does it take for phenibut to kick in?

Typically, it takes about two hours for phenibut to kick in. But it depends a bit on how your test subjects take it. Also, its effects are subtle, so it might start working without your test subjects noticing.

The phenibut half-life is about 5.3 hours [1], which means that the concentration in the body will go down by about half in that time.

Some research suggests that phenibut can be felt for up to 24 hours [5].

Buying Phenibut Online | 2022 Guide

Phenibut is legal for researchers to buy online—as long as you’re not in Australia, Lithuania, Italy, France, or Hungary.

It’s not approved as a medication in most countries, so it’s not publicly available at pharmacies either—with or without a prescription. The only countries where phenibut is accessible by prescription are Russia, Belarus, Ukraine, Kazakhstan, and Latvia.

As a researcher, you’ll typically have separate processes for obtaining research nootropics.

Either way, buying phenibut online is the best way to get it for research purposes. In our experience the best place in the world to buy phenibut is

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How To Take Phenibut | Verdict

Test subjects report powerful effects from phenibut. That's probably why you're concerned about advising subjects on how to take phenibut properly.

We know that it can be difficult to understand how your test subjects can take phenibut and what protocol you should use in your research. But it’s not that complicated. Basically, most nootropic researchers use phenibut capsules. If they buy phenibut HCL, it’s also common to mix it into a drink. With phenibut FAA, your research subjects can also put it under the tongue.



  1. Lapin I. (2001). Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug. CNS drug reviews, 7(4), 471–481. doi:10.1111/j.1527-3458.2001.tb00211.x
  2. Cheung, J. & Penn, J. (2018). Weekly dose: Phenibut. The Conversation.
  3. Ahuja, T., Mgbako, O., Katzman, C., & Grossman, A. (2018). Phenibut (β-Phenyl-γ-aminobutyric Acid) Dependence and Management of Withdrawal: Emerging Nootropics of Abuse. Case reports in psychiatry, 2018. doi:10.1155/2018/9864285
  4. Högberg, L., Szabó, I., & Ruusa, J. (2013). Psychotic symptoms during Phenibut (beta-phenyl-gamma-aminobutyric acid) withdrawal. Journal of Substance Use, 18(4), 335-338.
  5. Owen, D. R., Wood, D. M., Archer, J. R., & Dargan, P. I. (2016). Phenibut (4‐amino‐3‐phenyl‐butyric acid): Availability, prevalence of use, desired effects and acute toxicity. Drug and alcohol review, 35(5), 591-596.
  6. CDC. (2020). Notes from the Field: Phenibut Exposures Reported to Poison Centers — United States, 2009–2019.
  7. Ozon Pharm (n.d.), Fenibut (PDF). [In Russian].
  8. Hardman, M. I., Sprung, J., & Weingarten, T. N. (2019). Acute phenibut withdrawal: A comprehensive literature review and illustrative case report. Bosnian Journal of Basic Medical Sciences, 19(2), 125.
  9. Samokhvalov, A. V., Paton-Gay, C. L., Balchand, K., & Rehm, J. (2013). Phenibut dependence. Case Reports, 2013, bcr2012008381.

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