How much Phenibut should you take per day to promote positive effects while minimize the risk of side effects?
Phenibut is a nootropic used as an antianxiety agent that has a calming effect without interfering with mental performance. Users say that it helps them focus and improves mood when taken at appropriate dosages.
In Russia, this phenylated analog of GABA has been used for decades as an over-the-counter remedy for anxiety and nervousness. It is also used as a prophylactic before potentially stressful situations.
In the United States, it is not approved by the FDA as a drug for the treatment of medical conditions. It remains unregulated and can be purchased without a prescription.
Phenibut is growing in popularity and many users are curious about how much they should be using. Taking too much of this nootropic or combining it with certain other drugs can be dangerous which is why it is important to follow dosage guidelines closely.
This article looks at the most common phenibut dosage recommendations based on its medical sue in Eastern Europe. We also examine the adverse effects linked to excess use and taking too much.



- Powerful anxiolytic for stress reduction
- Stimulates GABA receptors & supports sleep
- Neuroprotective & supports cognitive function
How Much Phenibut Should I Take?
Related Topics
- What is Phenibut?
- User Review
- Benefits and Uses
- Dosage Recommendations
- Effects & Mechanisms of Action
- Experience Reports
- Anti-Anxiety Effects
- Using Phenibut for Sleep
- How to Take
- Negative Side Effects
- Withdrawal Dangers
- Risks with Alcohol Combination
- Comparison to Picamilon
- Buying Phenibut Guide
- Using Bulk Powder
- Primaforce Phenibut Review
- SNS Phenibut XT Review
Users should determine the correct dosage of Phenibut for their needs in consultation with their doctor.
Because this nootropic agent has not been approved by the US Food and Drug Administration, there are no standardized dosage guidelines available published by the FDA.
Different people will respond to the effects of phenibut differently. How much you should use will depend on several factors including:
- Your sensitivity to other GABA agonists like alcohol, Xanax and Valium;
- Your reasons for taking phenibut;
- Your current state of health;
- Age and bodyweight;
How much phenibut you should take will also depend on your gender, diet, physical activity level and various other factors.
It is always advisable to ask your doctor about the best dose of any new product you are considering.
Recommended Phenibut Dosage
The Natural Medicines Comprehensive Database (NMCD) states that there is no typical dosage for phenibut powder or capsules. This compound has not been studied enough in humans to determine an optimal dosage. [1]
The best source to rely on when determining a safe amount of Phenibut powder or capsules is medical authorities in Russia and other Eastern European countries where it is used as a pharmaceutical medication.
According to various online sources, phenibut dosage recommendations commonly range between 250-1000 milligrams (mg) per day. The manufacturers of Noofen recommend all dosages be taken after meals and with a glass of water.
For asthenia and anxious-neurotic states, it has been used at a dosage of 250 – 500 mg taken up to three times per day, under doctor supervision. It should not be taken in single dosages of greater than 750 mg per administration and treatment typically lasts for 2-3 weeks.
When used for general stress relief effects or in a nootropic agent, phenibut is generally recommended at 250 per dose mg in new users.
It is advised to start taking this compound at the low end of the dosage range until you determine how that substance affects you. Only gradually increase the dosage under the supervision of your doctor. Never take more than what is required to achieve your desired effects.
Some people take this product to help them get a good night’s sleep. Using a low dose approximately 1 to 2 hours before bedtime may make it easier to fall asleep and quiet your mind.
It is recommended to only take this substance on an occasional basis or as directed by your physician. One manufacturer recommends using it only two days per week with a minimum of three days in between to prevent tolerance for forming.
Doses over 2 grams (2000 mg) per day may increase the risks of phenibut side effects and may not promote any additional benefits.
Doses over 3 grams are often said to induce heavily-sedative effects and can be dangerous, especially for people with a low tolerance of this drug. Taking too much can cause a tranquilizer effect which could result in discoordination or slow reaction times.
The dosages described above are for the Phenibut Hydrochloride (HCL) form that is most commonly used in medications or sold as a bulk powder online. There is also a Free-Amino Acid form which is purported to be more potent and to require a smaller dosage.
According to some sources, when Phenibut FAA is taken sublingually (under the tongue), it can be up to three times stronger than oral administration. If using this method to take the powder, it is important to adjust dosing accordingly.

- Powerful anxiolytic for stress reduction
- Improves sleep and may reduce insomnia
- Neuroprotective and cardioprotective effects
Effects of Taking Phenibut
Phenibut’s mechanism of action is often compared to alcohol, but cleaner and without the lacking coordination, slurred voice, and other common alcohol-related side effects.
It stimulates some of the same receptors in the brain as alcohol. But when used appropriately, should not produce the same effects.
Phenibut’s scientific name is beta-phenyl-gamma-aminobutyric acid. It is a cyclical phenylated derivative of a brain chemical called GABA (gamma aminobutyric acid).
GABA is naturally produced inside the body and is used to reduce nerve excitability and to regulate muscle tone.
Synthetic GABA is available but is very poor at crossing the blood-brain barrier. In comparison, phenibut is able to easily cross the BBB into the brain.
Phenibut’s effects inside the brain are compared to GABA’s. Some college students use it to relax, boost sociability, and enhance cognitive function.
Some bodybuilders and other fitness enthusiasts take phenibut powder because it is said to increase production of HGH (human growth hormone) and indirectly enhance muscle size. However, there is no research available to assess this claim.
Other purported benefits include relief of anxiety and stress, improved memory formation and recall, increased sense of well-being, and better sleep.
In Russia, Latvia and the Ukraine, this drug has been prescribed for the treatment of the following medical conditions:
- Anxiety
- Alcohol Withdrawal Syndrome
- Asthenia
- Depression
- Depression
- Emotional Lability
- Insomnia
- Meniere’s Disease
- Motion Sickness
- Stuttering in Children
- Tourette’s Syndrome
- Post-Traumatic Stress Disorder
According to some sources, this compound also increases activation of dopamine receptors and possibly contribute to mood enhancement effects.
Alcohol and benzodiazepines like Xanax (alprazolam) and Valium (diazepam) are also GABA agonists. That makes taking phenibut with these substances possibly-dangerous, especially in high doses.
Dangerous Effects of High Doses
Taking too much of this compound can be hazardous to your health and must be avoided. There are various reports of people using larger doses of phenibut to induce euphoric highs.
Some college students use phenibut to help them overcome social shyness and feel better able to approach and talk to people of the opposite sex.
Some describe the experience as similar to that of taking Xanax or Valium, but with increased motivation instead of decreased motivation.
Some users report that phenibut intensifies the effects of an alcohol buzz. Other people take it as an alternative to alcohol claiming that it is safer and does not have adverse effects on the liver.
However, some review claim that this nootropic makes them less able to notice the effects of alcohol, and subsequently end up drinking too much.
There have been life-threatening reactions reported from people who took excessive dosages of this substance or combined it with psychoactive drugs.
Using it for extended periods of time at high doses without taking any breaks can also lead to tolerance and withdrawal symptoms when you stop taking it.
It is important to be aware of the consequences of overuse and never take more than what your doctor recommends.

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How Long Does Phenibut Take To Work?
The onset of effects for this nootropic agent is significantly longer than for other commonly used anxiolytics.
Many users state that they do not begin to notice the effects of phenibut until about 4-6 hours after taking it. How long it takes to work can vary depending on the user. Your experience may be different from those reported by other users.
Many users seem to recommend taking this nootropic drug about 5 hours before they want to feel its prosocial and calming effects.
How Long Do The Effects Of Phenibut Last?
Phenibut’s half-life is reported at about 5 hours. However, many users claim they continue to feel its effects for up to 24 hours after taking a single oral dose. The duration of effects appears to be highly variable.
Individuals who have impaired liver or kidney function may not be able to clear this substance normally and may need to adjust how much they take to compensate for this extended half-life.
If you have taken in any other calming substances (chamomile, lavender, cannabis, alcohol, etc.), or stimulants (caffeine, cocaine, methamphetamine, etc.), that will also affect how long this nootropic drug lasts in your body.
How to Prevent Withdrawal Symptoms
One downside to phenibut for some users is that tolerance to its effects seems to build rather quickly. According to various sources, this nootropic is best used in cycles or when taken only on specific occasions.
One way to cycle phenibut is to take it 3-4 days every week and take the other 3-4 days off. Some users report that they will take the powder every day for 2 weeks and then take 2 weeks completely off from using it.
Some people report withdrawal symptoms like nausea, vomiting, anxiety, irritability, agitation, brain fog, fatigue, cognitive decline, insomnia, and both visual and auditory hallucinations.
Users who develop a tolerance may need to slowly taper the dosages down to minimize negative effects during the withdrawal period. In some severe cases, professional treatment may be required.
Note that cross-tolerance is possible if you are taking other GABAergic substances.
Do not combine this substance with other compounds that increase activation of GABA receptors. Mixing phenibut with other GABA agonists can cause intense feelings of fatigue, grogginess, and sedation. Overdose is also possible.
Is Phenibut Safe?
NMCD states that there has not been sufficient research completed to rate the safety or effectiveness of phenibut. It should only be used under the supervision of a qualified physician to minimize the risk of negative effects.
Until more is known about this potent nootropic drug, you should avoid using phenibut powder or capsules if you are pregnant or breastfeeding.
Some user reviews state that a hangover is possible if you take too much, or if you drink too much alcohol after taking phenibut. Symptoms may include a headache, irritability, anxiety or brain fog the day after using this substance.
If you use this anxiolytic improperly, you might also experience side effects like ED (erectile dysfunction), decreased sex drive, low motivation, constipation, or grogginess.
Based on user reviews posted online, people generally report that it is well tolerated when it is used in commonly recommended dosages between 250-1500 mg/day. Mild side effects typically go away quickly on their own when they are experienced.
It is important to note that this drug has been used by millions of consumers in Russia and other Eastern European countries. When it is taken as directly, the risk of negative effects can largely be controlled.
It is always best to seek professional medical advice before beginning to use phenibut. Most of what is known about it comes from user reviews and anecdotal accounts. Use this nootropic sparingly and cautiously, especially if you are new to its effects.
Article last updated on: July 8th, 2018 by Nootriment