Phenibut Side Effects | What You MUST Know

Curious about Phenibut side effects? Then you’re in the perfect place.

Phenibut has recently become a popular nootropic in “social” situations — mainly because it’s so effective at reducing anxiety, boosting your mood, getting you in the mood for being social, and helping you sleep [1].

But there can be some side effects, including Phenibut withdrawal effects.

Luckily, these are easy to mitigate. While there are some Phenibut side effects, if you take the normal precautions and use it properly, it’s entirely safe to use.

P.S: Click here to order Phenibut from the world’s best vendor!

Consider this your comprehensive guide to Phenibut side effects, withdrawal effects, safety, and ways to make sure you have a good experience.

This is not medical or legal advice. This guide is strictly for entertainment purposes only. Always consult a medical professional before consuming any nootropic and always abide by the laws of your country. Please read my disclaimer page, too.

What is Phenibut?

Let’s start with what Phenibut is and why people use the nootropic.

Phenibut is a chain of amino acids, which just means it’s kind of like a protein. That’s why it’s totally legal to buy in virtually every country and why it’s sold as a supplement: because it’s basically a protein.

This particular chain of amino acids has a structure that’s a lot like a neurotransmitter, which is a chemical that your brain uses to send signals around your nervous system.

How does the nervous system work?

Here’s the gist:

Your brain controls your body by sending signals through your nerves. When one nerve cell ends and another begins, there’s a gap between them called a “synapse”. The message gets across the synapse to the other nerve cell using neurotransmitters.

The first nerve releases these chemicals into the gap. They then bind with receptors on the other nerve. So the amount of neurotransmitters in your synapses, the number of receptors you have, and how quickly the neurotransmitters are taken up all affect how you feel and behave.

GABA is an Inhibitory Neurotransmitter.

GABA is one of the most important neurotransmitters.

It’s known as an “inhibitory neurotransmitter” because it reduces activity in your nervous system. That seems like a bad thing, but it’s not. You definitely don’t want all of your brain activated all the time. Your anxiety and stress come from signals in parts of your brain, and you definitely don’t want those blasting 24/7.

So GABA helps your brain turn it down.

Phenibut mimics GABA.

Since Phenibut’s chemical structure looks similar to GABA, it’s able to have some of the same effects that GABA does [1, 2]. It reduces activity in the central nervous system — your brain and spinal cord. This basically means it helps your brain relax and chill out.

This is actually what alcohol and other “downers” do as well. They don’t all use the same mechanism, as they don’t all work on the GABA pathway, but downers as a group are responsible for reducing brain activity.

You feel relaxed, less anxious, and more chill.

Phenibut Increases Serotonin and Dopamine.

Phenibut also has the effect of increasing two other neurotransmitters, serotonin and dopamine, which both have a powerful effect on mood. Serotonin is related to feeling good, and dopamine is well-known as part of the body’s “reward” pathway. It is released when you do things that are pleasurable like eat, play video games, or have sex.

Phenibut causes these to be released, which is why it is such a powerful mood booster.

Phenibut Effects

Because it reduces excitability of the nervous system, Phenibut has a ton of interesting effects. Research has demonstrated that Phenibut can lead to:

  • Cognitive enhancement. Research has found that people that take Phenibut demonstrate better attention, emotional intelligence, and memory [3, 4].
  • Reduced anxiety. Research has consistently found anxiolytic effects from Phenibut [4, 5]. This is one of the effects that Phenibut is best known for.
  • Better sleep. In a sample of 62 people with anxiety, Phenibut improved energy levels, sleep, and reduced fatigue [6]. It was also found to improve sleep in several other samples [7, 8].
  • Reduced aggression. In animal studies, Phenibut has been shown to reduce aggression in fearful situations and improve social skills [9].

All these effects are why Phenibut has been used as a medication in several countries for many years. It’s potent and can have some really great effects.

Phenibut HCL powder

Is Phenibut Safe?

That’s great and all… but is Phenibut safe?

Yes, but there are some things to know.

It’s safe because most people that use it really don’t have any issues with it. I’m going to talk in detail about the side effects of Phenibut in a second, but I want to say at the beginning that these affect only a minority of users.

Milder side effects are a little more common, but severe side effects are quite rare. And, they typically occur only with constant use and with high doses. So if you’re using Phenibut properly as just a casual, occasional user and are taking small doses, chances are you’ll be fine.

It’s also important to note that there have not been any lethal doses every noted in the research [1]. No one has been reported to have died from it — compare that to alcohol, hey?

Yes, Phenibut is safe when it’s used appropriately.

Phenibut Side Effects and Safety

Okay, let’s dive into the side effects of Phenibut:


Some of the more mild and more common short-term side effects of Phenibut include [10, 11, 12]:

  • Headaches
  • Low blood pressure and increased heart rate
  • Agitation
  • Sedation and sleepiness
  • Excessive muscle relaxation or tremors
  • Nausea and vomiting

If taken in very high doses, Phenibut can also cause more severe side effects, although these are also much rarer [10, 13]:

  • Loss of consciousness
  • Hallucinations
  • Delirium
  • Serotonin syndrome

Side effects become much more likely when the dose a person takes is over 1 gram per day. 2 grams a day is the highest you should go, and anything over 3 grams a day is probably getting into dangerous territory.

In one case where a man took 30 grams of Phenibut had to be admitted to the ICU and felt agitated, sleepy, and experienced muscle jerking [11].

So don’t take 30 grams of the stuff. Take less than 1 gram and you should be fine.

Long Term

The biggest side effect with Phenibut in the long term is that it can lead to tolerance [14].

Tolerance occurs when your body adapts to the increased levels of Phenibut in your blood. Your body may get used to those elevated levels of Phenibut, and then stop producing your own GABA internally. Thus, you start to need more and more Phenibut to feel the same effects.

The best way to avoid tolerance is not to take Phenibut regularly. Think of it as good for special occasions, not an everyday supplement. Once a week is good, and definitely not more than twice.

Interaction effects

The other thing to remember about Phenibut is that it can interact with other substances and end up having a more dangerous effect [14].

Remember how Phenibut is a “downer” and works on the GABA pathway? Basically, that means you shouldn’t take it with any other “downers” or other substances that work on the GABA pathway. That’s because when you take two downers together, the substances could have a more potent effect, last longer, or have unexpected effects.

That means avoid taking Phenibut with any of the following substances that are downers or that work on the GABA pathways [14]:

  • Alcohol
  • Benzodiazepines
  • Anticonvulsant medications
  • Antipsychotic medications

Stay away from these and other “downers” and you shouldn’t have any interaction effects.

Phenibut Withdrawal Side Effects

What about Phenibut withdrawal side effects?

I’ve actually covered this in lots of detail in another article, but it’s important, so here’s what you need to know about Phenibut withdrawal.

Phenibut withdrawal occurs when a person has become tolerant of Phenibut [15] and their body has built up a dependence on it. Maybe it’s stopped producing its own GABA, and so it now relies on Phenibut to function normally.

The problem is when you start to reduce or stop taking it… you’ll experience Phenibut withdrawal symptoms. These occur because the body has reduced its own GABA as it has become dependent on Phenibut… and it’s not getting that Phenibut anymore. So your body has a lack of activation of GABA receptors.

The resulting Phenibut withdrawal effects can be very uncomfortable. They include [16]:

  • Loss of appetite
  • Nausea
  • Insomnia
  • Confusion
  • Restlessness and irritability
  • Dizziness
  • Fatigue
  • Increased sensitivity to light and sound
  • Muscle twitches and tremors
  • Rebound anxiety
  • Panic attacks
  • Heart palpitations
  • Hallucinations

Again, these are very uncomfortable, so don’t get in a situation where you get dependent on Phenibut. Do not use it every day. Use it 1-2 times a week, maximum.

Phenibut HCL

Phenibut Overdose

Phenibut overdose is, again, not super common. It really takes a lot to experience an overdose. Still, it’s possible.

In one case, a 20-year-old woman experiencing an overdose had a reduced level of consciousness and seemed to demonstrate delirium. In another case, a 38-year-old man also was experiencing delirium and was also agitated. He had combined Phenibut with both alcohol and cannabis. Both of these patients made full recoveries [13]. It wasn’t clear how much Phenbiut they took.

In another case, a 25-year-old man who also had alcohol dependence became unconscious after ingesting Phenibut. He was taking 3 grams a day for at least 4 days in a row. He recovered within about 7 hours and was fine after. A follow-up after a week found that he had no further issues [10].

Together, these cases suggest that it’s important to stay under 2 grams of Phenibut per day and under 1 gram in any given dose.

Phenibut Dosage | How to Minimize Risks

With all those potential adverse effects, is Phenibut safe?

Yes, Phenibut is safe, as long as you’re using it properly.

That’s the same with anything. Alcohol, other nootropics, and most drugs, in general, are usually fine as long as you’re not taking too much of it. Even caffeine can be dangerous if it’s taken in massive quantities [17]. But is coffee safe? Of course.

So just be careful to understand Phenibut dosage and you should be fine.

Phenibut for newbies

If you’re new to Phenibut and want to avoid the side effects, just make sure you start with a smaller dose. Newbies can start with the following dose to avoid the risk of Phenibut side effects:

  • 250mg in a single dose
  • taken in the morning, an hour before food

Try it on a Saturday or a Sunday when you’re not doing anything else to see what it’s like and how it affects your body. That way you’ll notice if you happen to experience side effects of Phenibut or allergies.

Phenibut Microdosing

You can even try microdosing to really reduce your risk of Phenibut side effects. A good starting microdose would be:

  • 50mg to 100mg in a single dose
  • In the morning, an hour before food

With doses as low as those, you’ll get a little of the benefits of reduced anxiety and boosted mood while really reducing your risk of experiencing Phenibut side effects.

Should You Be Concerned?

As I said, Phenibut is totally safe as long as you take the right precautions. I’ve outlined those with some doses above for you.

Basically, the best way to stay safe is to be aware of your Phenibut dosage and make sure you follow some good guidelines. These are:

  • Take a maximum of 1 gram of Phenibut in a single dose. Don’t take more than that.
  • Take a maximum of 2 grams in a single day. Never more.
  • Use it a maximum of 2 times a week. Don’t use it more often than that. Honestly, it’s best to stick with just one day to be safe.
  • Cycle off for a month every once in a while to avoid tolerance.
  • Don’t take it with other downers like alcohol or other GABA-based medications.

If you follow those rules, you should be fine and avoid all Phenibut withdrawal side effects.

Where to Buy Phenibut Online | 2020 Guide

Still interested? Give it a shot.

You can buy Phenibut online from pretty much anywhere. My only suggestion is to be really careful about where you’re getting it. Online supplements are big business these days, and some vendors just aren’t as careful about quality control and safety as others. In this game, you really want to make sure you’re getting a good, pure product. So really do your homework.

I always recommend LiftMode because they’ve consistently been on-point with everything I’ve ordered from them. More than just a good experience, though, they’ve set up their business in such a way that I feel safe ordering from them:

  • First, they post certificates of lab analyses for all their products, which makes me feel comfortable that I’m getting pure Phenibut, and not something cut with fillers (also, it works, which is how I know it’s legit!).
  • They also have a reasonable return policy (within 90 days) so if you end up with the wrong product for some reason, you don’t have to worry about the hassle of returning it all.
  • They have a number of convenient payment options including credit cards and cryptocurrencies like Bitcoin.
  • They have a great support team based out of Chicago. So if you do have a problem, you can actually get in touch with a person. Their email support is good too.

Since I’ve only had good experiences with LiftMode, these guys are my go-to at this point. I stay away from most other vendors.

Phenibut Side Effects | Verdict

Phenibut really can be a wonder drug for those of us with a little social anxiety, who want to sleep better, or who just want to go out and stay sober. It really works and it makes you feel like a balloon of positivity.

But it does have some side effects, and you should be aware of them.

Don’t be dumb with Phenibut and you’ll be fine. Just keep in mind that everyone has a different body and so Phenibut will affect everyone a bit differently.

If you’re new to Phenibut, take it easy, starting with a relatively small dose. See how it feels, and adjust as necessary. Here are some good guidelines to follow, one more time, to reduce your chance of experiencing Phenibut side effects:

  • Don’t take more than 1 gram of Phenibut in a single dose.
  • Don’t take more than 2 grams in a single day.
  • Don’t use it more than 2 times a week.
  • Cycle off for a month every once in a while to avoid tolerance.
  • Don’t take it with other downers like alcohol or other GABA-based medications.

If you do those things, you’ll be fine. Dig in—and enjoy it!


  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. Dambrova, M., Zvejniece, L., Liepinsh, E., Cirule, H., Zharkova, O., Veinberg, G., & Kalvinsh, I. (2008). Comparative pharmacological activity of optical isomers of phenibut. European journal of pharmacology, 583(1), 128-134.
  3. Zyablitseva, E. A., Kositsyn, N. S., & Shul’gina, G. I. (2009). The Effects of Agonists of Ionotropic GABA A and Metabotropic GABA B Receptors on Learning. The Spanish journal of psychology, 12(1), 12-20.
  4. Chutko, L. S., Surushkina, S. I., Iakovenko, E. A., Nikishena, I. S., Anisimova, T. I., & Bondarchuk, I. L. (2014). Cognitive and emotional impairments in patients with protracted anxiety-phobic disorders. Therapeutic archive, 86(12), 61-65.
  5. Ziablintseva, E. A., & Pavlova, I. V. (2009). Influence of GABA agonist phenibut on the neuronal activity and interaction in hippocampus and neocortex in emotionally negative situations. Rossiiskii fiziologicheskii zhurnal imeni IM Sechenova, 95(9), 907-918.
  6. Vorob’eva, O. V., & Rusaya, V. V. (2016). Pharmacotherapy of anxiety disorders in patients with chronic cerebral ischemia. Zhurnal nevrologii i psikhiatrii imeni SS Korsakova, 116(12. Vyp. 2), 49.
  7. Danilin, V. P., Krylov, E. N., AIu, M., & Rait, M. L. (1986). Effect of fenibut on the nocturnal sleep of patients with the alcoholic abstinence syndrome. Zhurnal nevropatologii i psikhiatrii imeni SS Korsakova (Moscow, Russia: 1952), 86(2), 251-254.
  8. Shypilova, E. M., Zavadenko, N. N., & Nesterovskiy, Y. E. (2017). Preventive treatment of tension headache in children and adolescents. Zhurnal nevrologii i psikhiatrii imeni SS Korsakova, 117(7), 36-42.
  9. Bagmetova, V. V., Krivitskaya, A. N., & Tyurenkov, I. N. (2015). Effects of phenibut and citrocard on non-competitive and competitive behavior during provoked aggression in animals. Bulletin of experimental biology and medicine, 159(1), 48-52.
  10. O’Connell, C. W., Schneir, A. B., Hwang, J. Q., & Cantrell, F. L. (2014). Phenibut, the appearance of another potentially dangerous product in the United States. The American journal of medicine, 127(8), e3-e4.
  11. Wong, A., Little, M., Caldicott, D., Easton, C., Andres, D., & Greene, S. L. (2015). Analytically confirmed recreational use of Phenibut (β-phenyl-γ-aminobutyric acid) bought over the internet. Clinical Toxicology, 53(7), 783-784.
  12. Schifano, F., Orsolini, L., Duccio Papanti, G., & Corkery, J. M. (2015). Novel psychoactive substances of interest for psychiatry. World Psychiatry, 14(1), 15-26.
  13. Downes, M. A., Berling, I. L., Mostafa, A., Grice, J., Roberts, M. S., & Isbister, G. K. (2015). Acute behavioural disturbance associated with phenibut purchased via an internet supplier. Clinical toxicology, 53(7), 636-638.
  14. Davies, M. (2003). The role of GABAA receptors in mediating the effects of alcohol in the central nervous system. Journal of psychiatry & neuroscience.
  15. 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.
  16. 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.
  17. Adamson, R. H. (2016). The acute lethal dose 50 (LD50) of caffeine in albino rats. Regulatory Toxicology and Pharmacology, 80, 274-276.


After utilizing nootropics for the better part of a decade, I realized the potent results these products produce -- with regards to productivity and cognitive enhancement. Soon thereafter, I became obsessed with finding the premier smart drugs on the market. Then using them to improve my life. When I'm not devouring everything I can about nootropics and the science behind why they work, you'll find me traveling around the world or in the gym.

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