Phenibut is a synthetic central nervous system depressant commonly prescribed in Europe to treat a number of psychological conditions including depression, anxiety, addiction and posttraumatic stress disorder.  Newer research suggests that phenibut might also increase motivation, alertness and concentration in healthy individuals. Phenibut is classified as a nootropic thanks to its cognitive enhancing properties.
Phenibut is an old and well-researched drug. It was invented in Russia during the 1960s, and doctors in that part of the world have recommended it to patients for decades. In the U.S., phenibut has not been approved by the FDA for clinical use, but phenibut may be sold and used as a nutritional supplement.
While people have been safely taking phenibut for a long time, it can be abused like any other drug. Dependency and withdrawal symptoms have been reported in individuals who take more than the recommended dosage, so limit your use to avoid phenibut addiction. 
Phenibut is a GABA derivative that can exist as a free amino acid (FAA) or as a salt (HCL). Phenibut HCL is the salt variety, which is why it is crystalline in texture. There are a few key differences between Phenibut FAA and Phenibut HCL.
Phenibut HCL vs. FAA
Individuals may notice that the FAA form is more “fluffy” than the HCL form. However, the FAA form is more expensive and is not conducive for supplementation. Due to its powdery texture, it is difficult to dissolve in a beverage or put in capsules.
The HCL form is easy to dissolve or put in capsules. It is also more cost effective than the FAA. The HCL compound has a less pleasant taste than the FAA form, but, since you can buy this in capsule form, this is a non-issue.
Benefits and Effects
Extensive studies of phenibut conducted on animals have unveiled a wide range of potential benefits for humans including:
Promoting Healthy Brain Functions
In rats, phenibut improved blood flow in the brains of rats, which resulted in reduced motor and sensory deficiencies related to stroke.   It also decreased symptoms of amnesia in rats exposed to high voltage shocks.  In addition to alleviating nerve pain, phenibut appears to defend neuroblastoma cells against hydrogen peroxide damage.  
Boosting Cognitive Capacity
For example, phenibut speeds up animals’ defensive reflexes and increases brain responses to stimuli, which improves overall learning capacity.   Phenibut has also demonstrated effectiveness at improving amnesia and passive avoidance conditioning.  
Phenibut is able to promote relaxation without drowsiness.  Because of this, Russian cosmonauts often used Phenibut. Phenibut allowed them to work in less than ideal conditions without succumbing to the effects of mood imbalance. 
There is some debate as to whether this product is a true nootropic. However, there is some evidence of its ability to enhance cognition.* In passive avoidance tasks, Phenibut showed enhanced learning and memory.  It also enhanced the performance of mice during swimming and rotating rod tests. .
During a forced swim test, Phenibut reduced immobility time to a significant degree.  Scientists use forced swim tests to measure activity related to enhanced mood. [38, 39]
This compound provides sleep benefits as well.* One study suggests this is because it may activate dopaminergic processes which cause sedation. 
Phenibut reduces fear and anxiety in animals.   Phenibut also makes rats less aggressive. 
Protecting the Heart
In combination with nitric oxide, phenibut reduces heart rate and contractility in animals under stress.   When paired with nicotinic acid, phenibut can prevent blood flow disturbances in animals following a stroke. 
Phenibut also helps with heart rhythm regulation, and it might defend the heart against alcohol-related damage.   In a study of pregnant rats with preeclampsia, phenibut normalized blood pressure and platelet formation while increasing blood flow to the uterus. 
Curbing Alcohol Abuse
In one study, phenibut decreased alcohol-dependant rodents’ urges to drink while protecting their bodies from alcohol-related damage.   Consequently, some people take phenibut for alcohol withdrawal. Because alcohol and benzodiazepines work similarly on the brain, some people find it helpful to take phenibut for benzo withdrawal, but these drugs should never be combined.
Defending the Immune System
Phenibut has proven helpful in controlling overactive immune systems and restoring suppressed immune systems by replenishing phagocytic cells .  
Improving Respiratory Issues
Phenibut injections stopped sleep apnea in rats.  It also increased breathing capacity during emotionally stressful situations. 
How It Works
Unlike GABA, Phenibut HCL can cross the blood-brain barrier (BBB).  This is due to the addition of a phenyl ring to its basic structure.  Individuals take this product because it promotes relaxation and has other cognitive benefits. [34,35] It is a GABAB receptor agonist which means it can support a healthy mood as well. 
Better known to chemists as beta-phenyl-GABA, phenibut was designed to resemble a chemical called gamma-aminobutyric acid, or GABA. The human brain naturally creates GABA, which produces a calming effect on the body.  The addition of a phenyl group in phenibut allows supplemental GABA to cross the blood-brain barrier.  Just like naturally occuring GABA, phenibut GABA slows overall neuronal processes by boosting dopamine production and blocking β-phenylethylamine.  Dopamine plays an important role in regulating emotions, motivation and happiness, so increasing dopamine is a primary goal of many antidepressants.
Phenibut works on the brain similarly to alcohol. Indeed, they share some of the same mood altering properties, but phenibut doesn’t come with the negative effects of booze such as impaired judgment and coordination.
Phenibut is typically sold under the brand names Noofen or Citrocard. You may also see phenibut alternatively spelled as fenibut.
As with other antidepressants, the optimal dosage of phenibut varies from person to person. However, unlike antidepressants such as SSRIs, phenibut shouldn’t be taken every day. In that regard, they are more like benzodiazepines, which are taken as needed. Speaking of which, phenibut should never be mixed with alcohol or benzodiazepines; these drugs can be deadly in combination.
Limiting phenibut use to twice per week should prevent you from developing a tolerance. If you ever feel like you’re not getting the same effect from your usual dosage, do not take more. Instead, take a few weeks off of phenibut, and it should work better for you in the future.
Phenibut is a particularly powerful drug, so it should always be started at low dosages. Based on phenibut reviews online, users have self-reported daily targets of 250-1000mg, but starting at a high dose can lead to unpleasant feelings of drunkenness often referred to as “phenibut high.” Due to phenibut’s long half life, doses should be taken at least 12-24 hours apart.
There are two main types of phenibut supplement: phenibut FAA and phenibut HCl. The FAA, or “free amino acid,” variety is typically sold as phenibut powder or phenibut tablets. It is more potent and consequently more expensive than phenibut HCl, which has a crystalline consistency. Phenibut HCl can be dissolved in water, but many users mix it with juice to masks the drug’s bitter taste. You may also find phenibut HCL capsules. Phenibut FAA isn’t very soluble, so it should just be swallowed and washed down with water. Whether you buy phenibut powder, phenibut pills or phenibut capsules, consult package instructions for recommended dosing. Do not exceed 1000mg per dose or 2000mg in a day.
How do I take Phenibut?
To promote mood and sociability:
The recommended dosage of Phenibut is 250mg. It is best to start with the lowest effective dose to assess tolerance.
Do not take Phenibut more than 2-3 times per week to avoid developing a tolerance.
Some people who take phenibut experience mild side effects like headache and increased depression.  Although it is safe when taken in strict moderation, phenibut may be toxic in high doses. Two case studies suggest that high doses of phenibut may result in delirium and decreased awareness.  A phenibut overdose could also cause drastic drops in body temperature. 
People who suddenly stopped taking phenibut after consistent high dosing often experience withdrawal symptoms. Therefore, it is possible to develop a phenibut dependency. Documented withdrawal symptoms include elevated anxiety, irritability, lightheadedness, insomnia, fatigue, reduced appetite, muscle spasms, heart palpitations and hallucinations.   Due to its potential for abuse, phenibut should be taken with precaution. It bears repeating that phenibut should never be consumed with alcohol or benzodiazepines.
What are some products that go well with Phenibut
- Fish Oil
- Bacopa Monnieri
- Alpha GPC
Phenibut is a good anxiety-reducing addition to any stack. To improve overall mood and restlessness, try combining it with phosphatidylserine and bacopa monnieri. Phenibut, L-theanine and centrophenoxine makes a great recovery stack for athletes. Pairing phenibut with aniracetam enhances mood and focus.
Taking phenibut with modafinil decreases the anxiety-inducing effects of the latter, so the combination can increase productivity without provoking stress. Since both drugs are so potent, use the minimal dose of each when taking them together.
Do textures differ from lot to lot?
Due to different suppliers and milling processes, there may be a difference in powder texture from one lot to the next. Some lots may be crystallized and others may have a finer consistency. Though the mesh sizes of the powder may differ, the product is still Phenibut HCL and mesh size does not affect potency.
“Powder City’s Phenibut is the best I’ve used, and I’ve been using various brands for a LONG time. It’s also very consistent from order to order, delivering consistent relaxation “on demand”,and puts you in a fantastic mood. As for the price? By FAR, the lowest cost on the internet (in any quantity) but especially 1 kilo. You won’t find it for less than $200/kilo, with one planet asking for $305.95/kilo! Great product, at a GREAT price… “– Rob R.
“I tried Phenibut HCL on one of the weekend sales from Powder City. I am looking to produce more GABA at night without directly worrying about taking GABA straight and very little of it crossing the blood barrier. I take Phenibut 3 nights per week to avoid saturation point dosage and maintain the effectiveness. So far, I can tell it is a comfortable addition to my L-Dopa (from Mucuna Pruriens, 98%) and natural growth hormone pulses. I will be back for more as Powder City is turning out to be a wonderful supplier. Thank you!”– Derek H.
“I must say I am very impressed with this supplement. Certainly has very noticeable effects when taken. Have found taking a smaller dose along with a few other supplements (caffeine, theanine, hordenine) seem to offer really good results for calm, focused, energy for a good 5 hours. Certainly helps with just relaxing and sleeping with larger doses if that’s your purpose. Of course have to be careful with avoiding building up a tolerance. Overall I have found this to be a great supplement and it has improved my overall mood day to day. Would certainly recommend purchasing form PC given their product has been great each time I’ve purchased and their shipping is extremely quick.”– John F.
“I’m not big on reviews, but for this company and this product, I felt obligated. Why do I feel obligated? I ordered this on Sunday, knowing it wouldn’t ship until the next day. Monday comes and I get an email saying it shipped. The phenibut arrived in my mailbox the very next day. I didn’t click 1 or 2 day shipping — just regular mail. That alone merits 5 stars. It’s customer service like that that’ll ensure I come back again – and I will. Now a little about the phenibut itself. It came packed very professional and secure in a heat resistant envelope. I think its heat resistant, anyway. Appears to be. There’s a tiny scoop included that was in a small plastic bag attached to the bigger bag of phenibut. Very convenient, I must add. I was dreading digging through the phenibut to get the scoop out. So that was nice. The phenibut quality is great. This is a potent stuff, so if you’re new to it, please use with caution and listen to advice from others who have used it before. I am more than pleased with my phenibut purchase from powder city. I would recommend this product, and I would also recommend powder city. Thanks!!! “– Thomas.
“Best I have ever tried. I have purchased 500 grams from a previous bulk supplement company and thought that was good until they were out of stock and stumbled across powder city. Powder city phenibut takes 1/2 the dosage to get the same effect as my previous vendor. Not only that it was shipped immediately which included a thank-you card with my purchase. Something seemingly small like a thsnk you card is appreciated and goes a long way in my mind. The product is spectacular and so is the service. I give it a five-star rating. I’ll be shopping here more for my nootropic needs.”– Mike
“This stuff does get you the desired effect of some confidence boost and such throughout the day, although it must be noted that it does taste rather awful, so if youre going to consistently use, maybe invest in a capsule mechanism. But with that if youre planning on consistent use it should be noted that it should really, only be used maybe twice a week and if that if you’re getting 3-4 days between modest doses, and youll have to really use your personal discretion on that portion of it because depending on how much you weigh, and the tolerance to it, that can change quickly. This being said, as always ramp up, and don’t just go for one large dose right at the git go because thats gonna be a one-way ticket to headaches and dizziness for hours to come. Also it takes a while to kick in so do not, take more while you’re waiting on the come up to begin.”– Anthony Z.
“I found myself more alert with exceptional concentration involving mental activities at smaller doses, which I prefer. I take it first thing in the morning and am fine all day. I sometimes take a little more later on. I do three days in a row with one-day break. I drink absolutely no alcohol and use no drugs whatsoever. A larger dose, after the initial energizing effects, did give me an uninterrupted night’s sleep and I had to take a nap the next day. I hope my honest review helps someone else decide if Phenibut is right for them. It is helping me. I got free shipping and it arrived in a few days.”– Lynne F.
“I placed my order of Phenibut late at night and had a confirmation the next morning and my order also went out that morning. This is my first experience with Phenibut and it didn’t disappoint. I was skeptical but the product is probably as good as the best reviews I’ve read. I also left my wife a dose in the fridge when I went to the gym. Got back and she’s talking up a storm and says she feels great. This product is so good I can see the abuse potential so please be sure to cycle it like youre supposed to and don’t use day in day out. I want to order kratom as well and maybe try that on my off days of phenibut. I certainly recommend Powder City as their communication, shipping, and quality is top notch. This was my first order and I stumbled across this site while researching phenibut.”– Chris M.
“Adding Phenibut to my routine on important days has been phenomenal. Powder city’s quality is amazing. It has a calming, non-drowsy effect that lasts all day. Even more impressive about phenibut is its sleep enhancing qualities. The night before a busy day, I’ll use the recommended dosage of phenibut 3 hours before bedtime. Not only do I enjoy an extremely relaxing evening, but I then sleep like I haven’t since I was a baby! 8 hours straight of sleep is something I haven’t enjoyed in years until I found phenibut and Powder City. Just be careful not to exceed recommended dosage as you may still feel tired in the morning. If you take the recommended dosage, you will sleep like you never have before. Thank you Powder City! “– JC