Issac Thorne

Last Updated February 12, 2022

Which is better for your research: phenibut capsules or phenibut powder?

Phenibut is a research nootropic with promise for applications like cognition, sociability, mood, and sleep.

But there are a few ways that phenibut can be taken, which can confuse researchers.

In this guide, we’ll cover what you need to know about conducting phenibut research, namely the difference between phenibut powder vs. phenibut capsules. After reading, we hope you’ll have a sense of which one might be the more advantageous choice.

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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?

Phenibut is a neuropsychotropic drug with anxiolytic and nootropic effects.

Chemically, it is an amino acid that mimics GABA—a neurochemical found in the brain [1]. GABA is an inhibitory neurotransmitter, which means that it slows down chemical signals and decreases nervous system activity.

While that sounds like it could be a negative thing, that’s not always the case. In highly general terms, slowing down your brain is one of the better things you can do if you suffer from stress or anxiety. Imagine the brain constantly firing on all cylinders—that would lead to a breakdown. GABA helps give the brain a break when it needs one, helping the subject relax.

Phenibut’s chemical structure is very similar to GABA, which is why it binds to GABA receptors [2]. Phenibut specifically binds to the GABAB receptors, which create slow inhibitory signals. Because phenibut binds to the receptors [3], it can act in the same way as GABA itself.

Phenibut also upregulates other neurotransmitters in the brain—in particular, serotonin and dopamine [1]. These are both involved in your mood and how you feel. Dopamine is often called the pleasure hormone. That’s why phenibut can also be a potent mood booster and can give the user a feeling of euphoria.

Phenibut effects

In Russia and some other countries of the former USSR, phenibut is used to treat or relieve a number of conditions, including [1, 4, 5, 6, 7, 8, 9]:

  • Convulsing
  • Spasticity
  • Stuttering
  • Vestibular disorders
  • Motion sickness
  • Tics
  • Asthenia
  • Anxiety
  • Depression
  • Post-traumatic stress disorder
  • Alcoholism and alcohol withdrawal syndrome
  • Disordered sleep

In most other countries, phenibut is not a prescription medication but rather an unregulated compound. In the United States, phenibut has the status of “New Drug” under the Federal Food, Drug and Cosmetic Act (FD&C Act).” This means that the United States Food and Drug Administration has not yet investigated or approved phenibut for use as a medication.

In countries where phenibut is available to researchers, the drug is studied for the following potential effects and uses:

  • Cognitive enhancement (i.e. as a nootropic);
  • Anti-anxiety effects, particularly in social situations
  • Sleep aid, namely for individuals with mental disorders
  • General stress relief

is phenibut safe

Phenibut Side Effects and Safety

Is phenibut safe?

We discuss phenibut side effects and safety in more depth in another article. We also have an article that provides more information about phenibut withdrawal symptoms. We recommend reading those articles for more detail.

Here, we’ll cover only the basics of what we know about phenibut’s safety profile.

Side effects of phenibut

Phenibut side effects can manifest in any user, but they’re especially more likely with larger doses. Side effects of phenibut include [10, 11, 12]:

  • Headaches
  • Agitation, anger and irritability
  • Low blood pressure and increased heart rate
  • Nausea and vomiting
  • Excessive muscle relaxation or tremors

If taken in extremely high doses, phenibut can also cause [12, 13, 14]:

  • Loss of consciousness
  • Delirium
  • Hallucinations
  • Serotonin syndrome

Interaction Effects

Also, consider that phenibut can interact with other medications and substances. In particular, it may interact with other central nervous system depressants.
Ensure that your test subjects stay safe by advising them to avoid taking phenibut with alcohol or any of the following [4]:

  • Opioids
  • Benzodiazepines
  • Antipsychotic medications
  • Anti-anxiety medications
  • Anticonvulsant medications
  • Sedatives or sleeping pills

Phenibut Dependence

Phenibut can be addictive. While most test subjects do not develop an addiction, researchers are advised to account for the possibility of dependence in their studies. If your subjects become physically dependent on phenibut and then stop taking it abruptly, they may experience phenibut withdrawal symptoms like [14, 15, 16, 17, 18, 19]:

  • Insomnia
  • Psychosis
  • Rebound anxiety
  • Anger
  • Agitation
  • Irritability
  • Auditory and visual hallucinations

Unless your study relates to the treatment of a particular condition, phenibut should not be taken more than one-two times per week. See our phenibut dosage guide for more details.

Phenibut Overdose

While phenibut is regarded as generally well-tolerated, there has been at least one death reported in the US that was the result of a phenibut-only exposure [20]. Information on the circumstances surrounding that death have not been publicly disclosed. As the community gathers more data on phenibut’s safety, researchers should continue to take extreme care when creating dosing protocols.

In Russia, where phenibut is a pharmaceutical drug, the dosing instructions on the drug’s package insert specify a maximum single dose of 750 mg and a maximum daily dose of 2.5 mg [4].

Phenibut Capsules vs. Phenibut Powder | Overview

When you start considering phenibut for your research, you might be confronted with a choice: should you buy phenibut powder, phenibut crystals, or phenibut capsules? What is the difference between these, and which might work best for you?

All phenibut, regardless of its form, is the same chemical substance. They should all work the same way on the body, and each option can be effective.

So consider that the difference should not have much effect on the outcome of your research. It’s more relevant to understand how you might administer the phenibut.

That said, there are some differences. Let’s go through them.

Phenibut Capsules

Phenibut capsules are really just phenibut powder placed inside of a digestible capsule.

What are the benefits of phenibut capsules?

  • Pre-measured. The user does not have to do any work to figure out the correct dosage.
  • Convenient. Capsules are easy to administer. Test subjects can just swallow them with some water, juice, or coffee. No mess and no fuss.
  • Travel well. Your test subjects can take them anywhere without having to bring gear to weigh the dosage. They can go to work or run their errands as normal without needing any special equipment.
  • No taste. In its other forms, phenibut can have a strong and unpleasant taste. Capsules are tasteless and easy to stomach.

How to take phenibut capsules

To take phenibut capsules, first figure out the appropriate dose for your subjects. If you’re not sure, our general dosage guide is a good starting point.

Vendors often sell capsules in doses of 250 to 300 mg of phenibut. To keep your research consistent, ensure that your test subjects receive capsules of the same dose and form—whether that’s FAA or HCL (more on that below).

Then, do the math. For example, imagine you purchase phenibut capsules of 250 mg. Provide your test subjects one capsule if your test protocol specifies a dose of 250 mg. Provide two if your protocol specifies a 500 mg dose, and so on.

How do your test subjects take phenibut capsules? Simple: swallow with water.

Phenibut Powder?

You’ll likely see phenibut powder in one of two forms: phenibut HCL and phenibut FAA.

Phenibut HCL has been synthesized to have an extra HCl molecule on the end. There is no change in the phenibut itself other than how your subjects take it. Since the HCl makes the compound ionic, it comes in crystals that dissolve easily in liquids like water or juice. So, your research participants typically take phenibut HCl by mixing it with a liquid and drinking it.

Phenibut FAA is the “Free Amino Acid” version of phenibut. It’s not ionic, so it doesn’t mix well in liquids, but your subjects can still mix it and drink it… it just might have an unpleasant, chunky texture. Your subjects can also put it under their tongue to dissolve sublingually, although some report that this also tastes unpleasant.

Note: Phenibut HCl should not be taken sublingually because it’s acidic. Regular administration may cause damage to the teeth.

What are the benefits of administering phenibut in powder form?

  • Control. Phenibut powder lets you have more control of how much your test subjects take. For example, if you want to provide them with a microdose, it’s easy to measure out 50 mg of phenibut powder. If you have capsules, it’s harder to customize their dose.
  • Easily dissolved. This holds true phenibut HCl, which is quite soluble. Just mix it in some water and drink. Some people even find this easier to take than capsules.
  • No fillers. Some brands that sell phenibut capsules add fillers. So you might prefer the powder because it’s less likely to have anything extra added to it.

How to take phenibut powder

First, figure out the right dose for your subjects and then use a scale to weigh it out. Easy.

Then, choose how you want them to take it (or give them the choice):

  • They may mix it in a drink and swallow;
  • If it’s phenibut FAA, they can put it under the tongue to dissolve;
  • You can put it in your own capsules (you can buy these easily from Amazon or other online vendors).

Phenibut powder vs. phenibut capsules: which is cheaper?

Phenibut powder is usually more cost-effective compared to phenibut capsules.

For example, we have seen one vendor sell 70 capsules of 300 mg for about $20. That’s about $0.94 per gram.

That same vendor also sells 40 g of phenibut HCL powder for about $20. That ends up being $0.49 per gram.

Based on this quick comparison, the capsules end up being about twice as expensive as the powder. You do need to spend a bit more on a scale or measuring cups initially, but in the long run, phenibut powder is less expensive.

Phenibut dosage for phenibut capsules vs. phenibut powder

This is something you might be wondering: Does the phenibut dose change depending on whether you’re taking it as a capsule or a powder?

No. We have not seen any evidence to suggest that the way a person consumes phenibut will affect the effects experienced from a given dose.

Phenibut is mostly absorbed in the small intestine. It would therefore arrive in the small intestine regardless of whether you take it as a capsule or powder.

Having said that, phenibut powder may kick in faster with some methods of administration, including if your test subjects are taking it sublingually. Phenibut can take a long time to start working—between 30 minutes to 90 minutes. So if the subject takes it sublingually, it may start to work a bit faster.
So…which one is better?

Neither is necessarily better. One may be more appropriate for you depending on your study’s design or simple personal preference.

Phenibut capsules might be better for:

  • Test subjects who are new to phenibut research and who may not know how to weigh their dose;
  • Researchers who want to minimize errors caused by test subjects measuring out the right dosage;
  • Researchers and test subjects who value convenience over the ability to control the dose;
  • Test subjects who may need to take phenibut when they’re out and about or traveling;
  • Test subjects who find the taste of phenibut unpleasant; and/or,
  • Researchers who don’t mind spending a bit more for the extra convenience.
  • Phenibut powder might be better for:
  • Test subjects who are experienced and not intimidated by measuring out their dose;
  • Researchers who value being able to customize their subjects’ dosage levels;
  • Researchers and test subjects who aren’t worried about the convenience aspect;
  • Test subjects who are happy to bring along their scale or measuring cups out and about as they’re traveling around;
  • Test subjects who don’t mind the taste of phenibut; and/or,
  • Researchers who are more price-conscious.

If you’re new to phenibut research or if your test subjects are inexperienced, it may be better to start with capsules. That way, your subjects can easily consume them without getting a scale and all that. They’re more accessible.

If you decide your subjects can handle the scale and measurements, then you may wish to use the powder from both the quality control and cost standpoints.


Where To Buy Phenibut Online | 2022 Guide

Ready to start your research?

Phenibut is a popular research nootropic, but you won’t find it in the store. Provided you’re a qualified researcher and reside in a country where phenibut is neither a prescription medication nor a controlled substance (e.g. United States), you can buy either phenibut powder or phenibut capsules from a reputable vendor.

Just be careful: Not all vendors are created equal. Some are downright scams, some won’t refund you if they send the wrong product, and some have the absolute worst customer service.

We recommend This is our go-to vendor for research-grade phenibut powder in either HCL or FAA form. has a solid reputation in the research nootropics community, a reasonable return policy, and high-quality product (verified with certificates of analyses posted on their website). With this vendor, you can be sure that you’re getting nearly 100% pure phenibut.

In addition, they ship all over the world, have a number of convenient payment options, and competent customer support.

In the event, you require phenibut in capsule form, we would only go with LiftMode. This vendor sells both HCL and FAA capsules in 70-count and 300-count containers at reasonable prices. With free shipping on all US orders over $39 and a loyalty program, the company knows what it takes to earn and keep your business. Recommended!

Ready to order Phenibut from the top-rated online vendor?

Phenibut Powder vs. Phenibut Capsules | Verdict

Continued phenibut research can provide a much better understanding of this promising nootropic. It is imperative that any research be conducted safely and in compliance with applicable local laws.

Phenibut can be studied in both powder and capsule form. If you want convenience and don’t mind paying a little extra, the capsules may be the better choice.

If you’re experienced with phenibut research, want to be able to tweak the doses, or are price-conscious, the powder might be your better bet.

Keep in mind that the two options are not mutually exclusive. In fact, it is common to test both the capsules and the powder to see which works better for a given research aim.


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