How long does it take for Phenibut to kick in?

Updated May 10, 2024 by | Reviewed by William Gallagher, MNeuroSci
(Estimated reading time: 9 minutes)

If you're like me, an avid Phenitbut user, then you've probably been wondering how long it usually takes for Phenibut to really kick in, right?

If that's the case then you've come to the right place, my friend. First of all, I absolutely LOVE Phenibut. The fact that it's legal and so easy to get still blows my mind to this day.

One of the things I especially love about Phenibut is how it makes me feel. Now, just to be clear, I have ZERO experience with other drugs, so the best way to describe how Phenibut makes me feel is to draw a comparison to how you feel waking up from anesthesia (that warm, cozy sensation in your body). Seriously, that's how it feels to me.

I'm also WAAAY more sociable at parties, in a better mood, and sleep like a little baby at night.

That being said it's important to point out that Phenibut will have a different effect on different people. Some people, like myself, swear by it whilst others don't really feel the effects of it.

I'm one of those people who can feel the effects of Phenibut up to 48-hours after ingestion. But exactly how long does it last? How long does it take for Phenibut to kick in? When and how should you take it and what's the ideal phenibut dosage for your specific goal?

.... Let's take a closer look!

What is Phenibut?

Phenibut is essentially a tranquilizer that mimics one of the neurotransmitters in your brain. 

Its chemical structure closely resembles that of the popular neurotransmitter; GABA which means that you can experience similar effects.

It is a medication that helps ease anxiety. It was prescribed in Russia in 1960 and used as a treatment for stuttering, insomnia, vestibular disorders, post-traumatic disorder, irregular heartbeat, and depression.

This depressant is a GABA-B agonist and goes by the name phenyl-GABA (B-Phenyl Y-aminobutyric acid). The phenyl-GABA is a synthetic form of gamma-aminobutyric acid (GABA), one of the brain's inhibitory transmitters.

The effect of GABA is to make your body feel relaxed and calm. A person with anxiety and nervousness will have more control over their feelings and thoughts in social situations.

It helps people who tend to overthink and those who are overly self-conscious by regulating their neural processing.

One positive effect of Phenibut is to reduce the feeling of negativity. In addition to that, it also has a sedative impact on the body.

The Background

As I've discovered, Phenibut isn't approved in western countries. Despite the availability, it's currently available as a supplement in many e-commerce sites and online stores. The history of Phenibut goes back to 1963 in St. Petersburg, Russia, when it was still called Phenigamma. It's considered an experimental drug for people who are undergoing psychiatric treatment.

The following year after it was made, they were able to document the said medication's tranquilizing effects.

By the year 1975 and after some successful treatments, Phe gamma became widely known worldwide as Phenibut. Before, soviet cosmonauts use Phenibut to take advantage of the mental stimulation and calming effects.

But today, it's used as an exercise recovery booster, sleeping aid, and mood enhancer. Aside from that, Phenibut is considered a "smart drug" currently sold in many online markets.

Overall, the effectiveness is considered low, and addiction to Phenibut is rare. But, this supplement is deemed "harmful" somehow, and it has garnered the attention of many agencies.

These agencies are looking into the thought that this supplement is currently available online. It has come to their attention that if the use of Phenibut isn't regulated, it may cause danger and addiction.

What You Should Know About Phenibut

As mentioned earlier, Phenibut is a synthetic form of gamma-aminobutyric acid (GABA), and it has an identical structure to GABA.

That means it is believed to activate the brain's GABA receptors while it delivers a calming effect to the body.

Since it enters the brain through the bloodstream, it is used as a critical ingredient for tablets and pills. So it's commonly sold as Anvifen, Adrafinil, Nufen, and Fenibut.


Anvifen is a brand name under Phenibut. Other terms of this nootropic drug are PHG, PhGAbA, Noofen, Phenigam, and Fenibut. It’s considered a depressant for the central nervous system that promotes relaxation, sleep, and reduces anxiety.

In addition to that, some people who tried it say that it also promotes cognitive functions, which help them concentrate on their work without being distracted.

Some parts of Eastern Europe and Russia considered Anvifen as a prescription drug to help people lessen their anxiety and stress.

In addition to that, it also helps a person to get enough sleep, treat alcohol withdrawals, increase strength and energy.

The availability of Phenibut products depends on what country you’re on. In some states, this nootropic drug isn’t regulated and doesn’t need to have a doctor’s prescription to purchase. But in Australia and UK, Phenibut and other brand names under Phenibut are banned due to addiction.

While people from Russia casually use Anvifen to reduce the feelings of stress, it does have dangerous side effects if not regulated and misused.

So taking this drug on high dosages can cause severe reactions that can cause withdrawal and tolerance symptoms. Thankfully, when used clinically, Anvifen can be practical and useful to treat the following disorders.

  • Post-Traumatic Stress Disorder (PTSD)
  • Chronic Fatigue Syndrome (CFS)
  • Vertigo Vestibular Dysfunction
  • Involuntary Bedwetting (Enuresis)
  • Motion Sickness (Kinetosis)
  • Alcohol Withdrawal Syndrome
  • Stuttering and Tic Disorders
  • Vegetative-Vascular Dystonia
  • Various Psychotic and Neurotic Disorders
  • Depression
  • Meniere’s Disease


Adrafinil is another smart, nootropic drug that is used in the place of Modafinil. People often use Adrafinil to increase their focus, alertness, and concentration. This smart drug belongs to the same category of eugeroic nootropics.

When it comes to the liver, it converts to Modafinil. Unlike any other nootropics or Modafinil, you can actually purchase Adrafinil easier in the United States as it’s also not regulated in the area. But, to avoid potentially dangerous side effects, Adrafinil should be used and taken correctly.

The history of Adrafinil goes back to 1974 where it was first developed by a group of scientists at Lafon Laboratories, a French pharmaceutical company. A scientist named Michel Jouvet and his colleague researched new analgesics and suddenly produces benzhydryl sulfinyl compounds.

That’s when they come across Adrafinil. This nootropic doesn’t have any pain-relieving effects, but it’s considered as a eugeroic or a compound that promotes wakefulness.

People who have tried taking Adrafinil report that the compound can improve cognitive ability and has been significant among people diagnosed with ADD or ADHD. A lot also have positive reviews about the said nootropic drug, and many are claiming that it’s the best nootropic in the market that’s legal.


Another brand-name under the prescription nootropic drug Phenibut (Aminophenylbutyric Acid Hydrochloride) is Noofen. So, Noofen is currently sold in Georgia and Latvia. It’s distributed along with particular European countries and is manufactured by a pharmaceutical company known as JSC (Joint Stock Company) Olainfarm.

Noofen is currently available as a dietary supplement and can be purchased without any prescription in the United States.

This nootropic tablet is used to treat asthenic conditions, insomnia, anxiety, Meneries’s disease, traumatic brain injury, stuttering and tics, stroke, vertigo, and many more. It’s often used off-label because of its tranquilizing and mood-enhancing effects. In addition to that, Noofen is mostly useful at analysis paralysis, improving confidence and shyness.

A typical user described using Noofen to be more on the positive side as it helps people have more comfortable conversations and socialize without overthinking the words you wanted to say.

Here are some of the anecdotal benefits of using Noofen:

  • It can aid Lucid Dreaming (Vivid Dreams).
  • It can improve sleep quality and sleep latency.
  • Boost confidence and sociability in particular situations.
  • It promotes positive thinking and outlook without being “High”.
  • For bodybuilders, it may help increase nighttime Human Growth Hormone.
  • It can streat ADHD symptoms and improves focus.
  • It can increase motivation which gives drive to complete any tasks.
  • Has a high possibility of preventing panic attacks and unexplainable fear.
  • It can promote peace of mind and minimize thoughts that are overactive.
  • Enables users to be calm and less irritated when it comes to chaotic situations and small problems.
  • It can help lessen anxious thoughts and reduce the feeling of stress.


In addition to Adrafinil, Noofen, and Anvifen, Fenibut is a brand name under Phenibut as well. Fenibut capsules and powder consist of sedative and anxiolytic effects.

It’s useful to increase prosocial behavior, induce relaxation, and reduce anxiety. Apparently, Fenibut isn’t approved for clinical use and is considered illegal in the United States. However, in some other countries, especially Russia, it’s legal and used to treat health conditions and mood disorders.

People usually order Fenibut online as it also improves mental focus, stress reliever, promotes standard sleep patterns, and mental calmness.

The history of Fenibut goes back to the year of 1960 in Russia (Soviet Union). It’s also used by Soviet Cosmonauts to give them peace of mind while on space missions. According to them, it helped them focus better on what they’re doing without having problems with their cognitive function.

Today, like the other nootropics, it’s used as a treatment for conditions such as Meniere’s disease, vertigo, alcohol withdrawal, and many more.

Fenibut works best by mimicking the effects of an inhibitory neurotransmitter. It activates GABA receptors that play a significant role in mental activities, arousal, and regulating moods. In Russia, Fenibut has many uses and advantages, and some of those are prescribed by doctors to treat and prevent conditions including:

  • It can treat depression.
  • It can lessen the feeling of Anxiety and Fear before diagnostic and medical procedures.
  • Used to treat Post-Traumatic Disorder (PTSD).
  • It can treat motion sickness or Kinetosis.
  • Used to treat neurotic patients or lessen the chances of having a poor sleep in psychosomatic.
  • Used to treat Vestibular disorders.
  • It can treat Stuttering and Tics.
  • Used to treat drug withdrawal symptoms.
  • Used to treat various disorders characterized by loss of strength or asthenia.
  • It can also clear the tension you’re feeling.

Is It Safe to Take Phenibut? 

I was curious when I read about Phenibut because some reviews say that the effects are exceptionally positive. Some also say that it’s not good for your health. But the most accurate answer to the question is that it’s really hard to say.

One of the reasons why it’s banned in other countries is because some people tend to abuse this nootropic drug. The only countries Phenibut is allowed as medication are Kazakhstan, Russia, Ukraine, and Latvia. Apparently, it’s used to treat disorders such as PTSD, ADHD, Kinetosis, and many more.

Other than those countries mentioned, two more countries considered Phenibut as a legitimate medication: Austria and Hungary. But, these countries have marked Phenibut as a controlled substance. Overall, the status of Phenibut isn’t entirely clear with the rest of the world.

Only Europe and the USA consider this nootropic drug as a legal nutritional supplement, but it’s still not authorized as a medication. Until today, the Food and Drug Administration (FDA) yet hasn’t approved Phenibut as a legitimate medication.

While it’s widely used to treat any disease or disorder, there has been no confirmation whether this nootropic drug is effective or not.

In addition to that, there’s a warning issued by the FDA to any companies who claim that Phenibut is a bona fide type of dietary supplement.

There may be scientific studies about how this drug works and its effects, but the tests have been conducted mostly on animals and not on humans.

It has come to their attention that without any sufficient evidence on how Phenibut affects humans, it will remain questionable if this drug is safe.

The Side Effects and Withdrawal Symptoms of Taking Phenibut

There’s a reason why Phenibut should only be taken on regulated doses, and one of them is the side effects. If it’s taken on higher doses, side effects include impaired motor coordination, loss of balance, and hangover may occur.

One disadvantage of taking Phenibut repeatedly is that it causes tolerance. This means, as time passes, you need to take more of the nootropic drug to achieve the effects you expected.

Since Phenibut is a depressant to the central nervous system, you should work on heavy machinery while it’s still in effect.

Here are the common side effects of using Phenibut:

  • It can cause headache when not regulated
  • Some may have allergic reactions due to the chemical compound of Phenibut
  • It can cause dizziness
  • Agitation
  • Somnolence
  • Sedation

Here are the common withdrawal symptoms caused by Phenibut:

  • Depression
  • Paranoia
  • Tremore
  • Reduced appetite
  • Irritability
  • Nausea
  • Cognitive Deficits
  • Aggression
  • Hallucinations
  • Decrease of pain threshold
  • Fatigue


Phenibut isn't something you can just take at any time. Even if you live in a country that doesn't regulate the use of this nootropic drug, you shouldn't use it often. Unless a doctor prescribed you, you could take whatever is asked to take.

As long as it's legal and you have the right prescription, then you don't have to worry about it being a dangerous drug. But, if you have been taking Phenibut for a period of time and wanted to discontinue it, you should consult your healthcare provider or doctor first.

Many have been using Phenibut abusively, and this can cause addiction. Honestly, it'll be hard to get out of that state once you're accustomed to it.

Others may need to consider having a medical detox. But, with a little control and regulation, then I'm sure that'll be effective in many ways. The information I've written here will surely help you understand Phenibut and its effects.