When it comes to a nootropic supplement for anxiety, few rival the popularity and efficacy of Phenibut. Created in Russia in the 1960s, this drug is still used there for the treatment of depression, asthenia (lack of energy and/or weakness), anxiety, insomnia, and fear. (1)
As a nootropic, it helps to promote a calm, positive mood, with a slight cognitive boost at low doses. While its effects on cognition are not as strong as those of many common nootropic supplements, it does exhibit some cognition enhancing effects.
When taken in higher doses, many report feelings similar to Xanax or alcohol, feeling calm and slightly buzzed, but without a detrimental effect on focus and motivation.
Thanks to its potent anxiolytic effects, Phenibut is often part of nootropic stacks. By pairing it with nootropics known to improve memory and brain health, neurohackers are able to promote a relaxed learning state. This is particularly popular with students during exam time.
Where Is Phenibut Legal?
Phenibut is legal in the US and Canada, where it’s not classified as a controlled substance and can be purchased without a prescription. In the UK it is unlicensed and unregulated, making it legal to possess but not legal to sell. This makes it difficult to find, however you can purchase from outside of the country and bring it in if you’re determined to give it a try. In Australia it’s categorized as a Schedule 9 prohibited substance, making it illegal to sell or possess.
Mechanisms of Action
A clue as to how this compound works is in its chemical name: gamma-aminobutyric acid, also known as GABA. GABA is our primary inhibitory neurotransmitter, helping to promote a calm mood, fighting anxiety, stress, and insomnia.
Phenibut is a phenylated derivative of GABA. In supplement form, GABA is unable to successfully penetrate the blood-brain barrier. The unique chemical composition of Phenibut allows it to cross this protective barrier and exhibit calming effects on our neurons (brain cells).
Once inside the brain, it works as a GABA-mimetic, acting mainly on GABA(B) receptors, with some action of GABA(A) receptors. (1) It also opposes the action of Beta-phenylethylamine, or PEA, an endogenous chemical that is involved in anxiety.
Benefits, Effects, & Uses
Anxiety and Aggression
While user reviews on the benefits of Phenibut as an anxiety-fighting compound are seemingly endless, there have not been many studies to evaluate this effect. Presently there have been animal studies that have found this drug to decrease anxiety, fear, and aggression. (3,4,5)
User reviews report changes in appetite when using this nootropic. Studies suggest that withdrawal symptoms from this compound may lead to reduced appetite, however no studies have been done to confirm if this carries over to when using this compound. (1)
Studies do support the role of GABA on appetite. GABA receptors are found not only throughout the central nervous system, but also in the gastrointestinal tract. (13) Some users report increased appetite when taking low doses, and studies suggest that GABA(B) agonists, such as Phenibut, may actually increase appetite.
Cognitive Benefits: Learning, Memory, and Neuroprotection
Multiple animal studies have found nootropic benefits of Phenibut. In one study on rabbits, supplementation in early life was found to accelerate defensive reflex and conditioned inhibition development – this suggests that this drug may help to improve memory storage and learning. (10)
Other animal studies found this nootropic to exhibit anti-amnesic effects, neuroprotective properties, and reduced cognitive injury from stroke. (9,11)
Thanks to its calming and slightly sedative effects, many who use this drug for anxiety report benefits with sleep and insomnia. This effect is likely to be more pronounced in those suffering from anxiety-induced insomnia.
Animal studies have found this drug to protect the heart during periods of stress, improve heart rhythm, and protect from cardiac damage caused by acute alcohol intoxication. (6,7,8)
Strengthens the Immune System
Chronic stress and anxiety are excitatory states that have been found to lead to a weakened immune system. It doesn’t come as much of a surprise that Phenibut, likely through its ability to calm excitatory responses in the body, has been found to restore the immune system of mice. (12)
Other Supplements Like Phenibut
Many neurohackers wonder what the best substitute for Phenibut is. Whether this is due to a lack of availability of Phenibut in your country, a desire to cycle it with another anxiolytic to avoid tolerance or withdrawal, or lack of desired effects with supplementation, there are many viable options.
Here is a list of alternate anxiety-fighting nootropics:
- Picamilon: Fights stress and anxiety while increasing concentration, mental energy, and cognitive function. Chemically it is niacin (a B-vitamin) plus GABA, and it works largely through its impact on the GABAergic system
- Aniracetam: This member of the racetam family of nootropics harnesses the impressive benefits for memory, learning, focus, and brain health that racetams are known for, with additional anxiolytic properties. It is known to help reduce stress and depression, promoting a positive mood.
- L-Theanine: Green tea is known for its ability to boost energy and concentration while supporting a calm mood. These benefits are largely thanks to the amino acid L-Theanine, which is found in high concentrations in green tea.
- Ashwagandha: This natural adaptogen has been shown in numerous studies to be quite effective at reducing stress in humans.
- Rhodiola Rosea: Another adaptogen, Rhodiola Rosea is able to fight all three types of stress: emotional, physiological, and cognitive. This means that you may experience less stress while also healing faster from physical stressors, such as exercise or injury.
- Mind Lab Pro: If you are looking for a nootropic supplement that is a quality mixture of mood-boosting and cognition-promoting compounds, Mind Lab Pro is one of the best on the market. Every ingredient is natural, leaving you with a noticeably powerful nootropic when it comes to mood, anxiety, focus, memory, and learning, with very few side effects.
Phenibut vs GABA
GABA is a neurotransmitter produced endogenously in the human body. Synthetic GABA supplements do exist with purported benefits of promoting relaxation and a positive mood.
Phenibut acts mainly through mimicking GABA in the body and mind – the benefit with Phenibut over synthetic GABA supplements is that it is more capable of crossing over the blood-brain barrier, and thus its benefits on mood and cognition are greater than those of synthetic GABA.
L-Theanine vs Phenibut
L-Theanine is a natural compound found in high levels in green tea. Rather than mimicking GABA, it naturally increases the levels of GABA and other neurotransmitters in the brain.
Additionally, it alters brain waves, resulting in increased alpha and theta brain waves. These brain waves are associated with focus, relaxation, and creativity. It is also known to inhibit the release of glutamate, the excitatory neurotransmitter that can lead to stress and anxiety.
When it comes to anxiety relief, most people find Phenibut more powerful, however this comes with the risks of tolerance and
withdrawal. If you are looking for a more subtle anxiolytic effect paired with a natural well-rounded nootropic, L-Theanine is a good option.
Phenylethylamine HCl vs Phenibut
Phenylethylamine HCl, also known as PEA, is a compound that is produced endogenously in humans. It is known to help with mood, attention, energy, memory, and weight loss. It works through increasing the release of dopamine, norepinephrine, b-endorphin, and acetylcholine.
If you are looking for a nootropic mainly to fight anxiety and stress, Phenibut is the best option. PEA is better for overall improvement of mood outside of anxiety disorders, along with increasing learning ability and focus
Piracetam vs Phenibut
Piracetam is the first member of the racetam family, and the first nootropic compound. Chemically, it is a synthetic derivative of GABA that is mainly used for its ability to improve memory. It is well-studied and considered safe when taken at recommended doses.
Unlike Phenibut, Piracetam is not particularly powerful at relieving anxiety.
Noofen vs Phenibut
Noofen is simply the brand-name for Phenibut sold in certain countries, including Georgia and Latvia.
Phenibut FAA vs HCl
There are two versions of this supplement to choose from: Phenibut Hydrochloride (Phenibut HCl) or Phenibut Free Amino Acid (Phenibut FAA). Phenibut HCl is the most widely used form of this nootropic, and is best suited for taking in capsule or tablet form.
Phenibut FAA is best for sublingual use, and is gaining popularity among neurohackers. Many report this form to be around three times as potent and bioavailable, so you may need a smaller dose of FAA in comparison to HCl. This form is more expensive than the HCl form.
Best Phenibut Stacks
Phenibut is one of the most commonly stacked nootropics – this is largely due to its providing a very powerful singular benefit, rather than a balanced array of benefits. By stacking this drug with other nootropics, you can tailor your anti-anxiety stack to include additional health effects.
Sulbutiamine and Phenibut
Sulbutiamine offers a subtle boost in energy, which stacks well with Phenibut for the goal of boosting motivation and energy while simultaneously promoting a calm and relaxed mood.
Phenibut and Kratom
If you suffer from debilitating social anxiety, this combination may help you find relief. Kratom and Phenibut are both powerful anxiolytics. This stack is best for those suffering from anxiety disorders – it is not your typical mood-boosting nootropic stack.
Aniracetam and Phenibut
Users report a synergy between these two anxiolytic nootropic compounds. This isn’t too surprising as their mechanisms of action are different, so they work on reducing stress through different paths. As Aniracetam does not lead to withdrawal, it can be helpful to stack with Phenibut, which you should cycle regularly.
Phenibut and L-Theanine Together
L-Theanine is a compound found in green tea that is touted for its health benefits. This compound is frequently stacked with caffeine to promote motivation and focus without the jitters of too much caffeine on its own. Both L-Theanine and Phenibut are known for their anxiolytic properties, which work synergistically thanks to different ways that they exert their benefits in the body. Stack all three to experience a calm, motivated concentration.
Phenibut and Piracetam
Piracetam and Phenibut are often stacked to provide a well-rounded nootropic experience. The Piracetam offers the brain health, memory, and learning boost while Phenibut works to reduce anxiety and stress.
Noopept and Phenibut
Just as Phenibut is one of the most potent anxiolytics, Noopept is one of the most powerful nootropics when it comes to memory, learning, and brain health. Combining these two can be good for an experienced neurohacker who is looking to notice very dramatic changes in cognition and mood.
Phenibut and Choline
Phenibut and choline are most frequently stacked together to promote athletic performance, thanks to its combined effect of reducing stress and supporting human growth hormone levels.
Phenibut and Phenylethylamine
Some users report Phenibut to help reduce the anxiety experienced when supplementing with Phenylethylamine (PEA). Outside of this use, it is not too common to stack these two nootropics together.
Dosage Guide: How to Take Phenibut Safely
While there is no recommended dosage with this compound thanks to insufficient human studies, users have experimented enough to provide a good guideline. Most users will take anywhere from 250 to 1,000 mg/day – as with most other nootropics, it is advised to start at a low dose and work your way up, until you find the right dosage for you.
Is Phenibut water soluble?
Phenibut is water soluble, so you do not need to take it with food. Taking it on an empty stomach is fine. If using the powder, mixing it with juice helps to mask the bitter taste. In order to avoid tolerance, you will either want to only take it when you need it, or cycle, taking up to a few days on and a couple of days off.
How long does Phenibut take to kick in?
Most users will start to feel it kick in slightly around 30 minutes post consumption, with the effects slowly building and lasting around 12 hours.
Half Life: How long does Phenibut stay in your system?
With a half-life of roughly 5 hours and total elimination from your system not until 24 hours, it is important not to take too much of this compound in a 24 hour period.
Because of the moderate half-life, some users will break their dosage up into two doses during the day, however many others report still feeling an “afterglow” the following day from one dose early in the morning. If you’re wondering when to take it, most users will dose one time in the morning, and some will include a second dose around lunchtime.
Be careful when using this drug for sleep. The dosage for sleep is the same as for anxiolytic purposes, however it should not be used every day because of tolerance risk.
Does Phenibut show up on a drug test?
Phenibut does not show up on a standard drug test.
Phenibut Side Effects with Different Doses
When taken in low doses, user reviews and limited studies suggest that this drug helps to encourage a positive and calm mood while enhancing cognition.
It is used as a prescription drug in Russia for the treatment of anxiety, depression, difficulties sleeping, PTSD, and asthenia. (1,2) There are no published human trials available outside of Russia, which makes drawing conclusions about the safety and side effect profiles of Phenibut challenging. Animal studies support the use of Phenibut for anxiety, fear, aggression, memory, learning, and neuroprotection. (3,4,5,6,7,8)
Understanding not just the benefits, but also the risks and potential negative side effects, of any nootropic supplement that you add to your stack is of critical importance.
This understanding can help you to determine your dosage, how often you take the drug, and what other drugs you stack it with. It can help you to pinpoint when you are experiencing side effects so that you can adjust your dosage or eliminate a nootropic altogether.
Intermittent and low doses of Phenibut are generally well tolerated. When taken in higher doses, or daily for extended periods of time, Phenibut is know to come with a side effect profile that users need to be aware of.
Largely thanks to user reviews and animal studies delving into the mechanisms of action of this compound, a fairly good understanding of the risks of supplementation can be drawn.
Common Phenibut Side Effects
Side effects reported by user reviews at lower doses include:
- Loss of appetite
- Mental and physical fatigue
- Mild stimulation
When taking higher doses, many users report feelings similar to being drunk or sedative effects, similar to those of powerful anxiolytic prescription drugs like Xanax. In addition to the side effects listed above, at high doses users have reported:
- Heart palpitations
- Respiratory depression*
- Motor Impairment and trouble with balance
- A “hangover” like effect
One user on Longecity reported waking up and feeling terrible, as if he’d drank too much alcohol and felt his ears ringing. He then experienced severe heart palpitations, describing it as “thudding extremely hard in my chest.” He said he felt like it stopped at one point before rapidly resuming rhythm again.
Another user, who claims he “read up on it” before taking a large dosage, reported “dreadful side effects” once he discontinued usage. He says he had a strong heart, but regardless, his experience landed him in the hospital with several heart palpitations, anxiety, and cold sweats.
Other users report feeling like their heart rate is jacked up like they just finished a set of sprints. Irregular heart beat was commonly reported, varying from fast to slow.
*Respiratory depression and some other more serious side effects are most common when mixing Phenibut with other depressant drugs, including alcohol, Xanax, opioids, and tranquilizers.
Loss of Appetite
One user reported feeling a varying effect in appetite, depending on the kind he was consuming. He said the “large crystals would completely destroy appetite” and he wouldn’t feel like eating for several days.
One Longecity user reported feeling like he couldn’t use the muscles in his face to form a smile. He said the depression was very deep, and he didn’t even feel like responding to texts or calls. He would spend his day on his couch staring at the TV like a zombie, not feeling awake or asleep hours.
Overdose Side Effects
You can overdose with Phenibut. An overdose can lead to lowered blood pressure, liver or kidney problems, and seizures, among other serious adverse reactions. An overdose is far more dangerous when combined with other depressants, including alcohol, opioids, narcotic drugs, or sedatives.
Phenibut Long-Term: Withdrawal
Thanks to how Phenibut works, people can rapidly form a tolerance. This tolerance leads to lack of efficacy at standard doses, and even withdrawal symptoms after cessation.
You can tell that you are developing tolerance when the same dosage that has worked for you in the past does not yield the same results. The last thing you want to do in this situation is increase your dosage when it stops working – high doses increase side effect risk and likelihood of difficult withdrawal symptoms. If too much Phenibut is taken for too long of a period of time, this may lead to health complications, particularly liver health.
Phenibut withdrawal can lead to feelings of:
- Reduced appetite
- Brain fog that can last for days or weeks
- General fatigue
- Trouble thinking clearly
- Heart palpitations
There is one case study examining a 35 year old male in the US with Phenibut dependence. (2) Initially the drug helped him with insomnia, alcohol cravings, and anxiety. By the time he checked himself into a clinic, he was experiencing withdrawal symptoms so severe that they would kick in 3-4 hours after supplementation, and resulted in his inability to work or get along with his family. He was taking very high daily doses of both Phenibut (8 g/day) and kratom (18 g/day).
It took 9 weeks of gradually substituting Phenibut with Baclofen, and 12 additional weeks to then taper off of Baclofen, before he could fully resume his normal life.
The good news? His story is not typical, and if you arm yourself with the appropriate knowledge, you can avoid dependence and withdrawal. There are many strategies that will help keep you safe from the more severe side effects attributed to this supplement. If you use Phenibut cautiously, you can experience the benefits without a high risk of adverse side effects.
How to Avoid Phenibut Side Effects
It is important to recognize that a safe dose for one person may be too much for another person – everyone’s response to this nootropic will differ. Due to the risk of side effects and withdrawal, it is recommended to start out with very low doses of Phenibut and slowly work up until the ideal dosage is found.
Most users take between 250 and 1,000 mg/day, either in one dose in the morning or split between one dose in the morning and the second around lunchtime. This compound is not completely eliminated from your body until around 24 hours post ingestion, so it is important not to re-up on the same day, but rather slowly increase your dose until you find your sweet spot.
While some people do report needing more than 1,000 mg/day, it is important not to exceed 2,000 mg/day to protect your health.
Another good idea is to either cycle with Phenibut or only take it intermittently, on days where you really need an extra anxiety-fighting boost. Limiting your use to only a couple of times per week may be best.
A common cycling schedule can be t
wo days on, two days off, or one week on, one week off. User reviews vary on how long it takes to feel tolerance, with some reporting up to one month being alright, but other users stressing never to take it daily for more than one week in a row.
Honest Phenibut Reviews We Found
When combing through reviews on Reddit and Longecity, you will find plenty of positive and negative experiences. There are users who, contrary to advice, have taken Phenibut daily for years or intermittently take mega-doses (both of these strategies are ill-advised due to side effects, tolerance, and withdrawal – click here to learn more about Phenibut safety).
There are also those who follow the advice and only take it intermittently or cycle frequently. We will include an example of all of these reviews to help you see the diverse Phenibut online experiences.
Review #1: Only When Needed – With a Warning
A Reddit user found luck with only taking this drug 2 times per week and generally took kratom on their off days. They began with a 700-800 mg capsule and did not feel anything, so they increased it to 1.4-1.6 grams on Mondays and Fridays. This dosage worked well for them for a couple of months.
During a rough patch they decided to take their typical dose for three days in a row. On day three, the user reported never having felt that great before – unfortunately, the next three days were a struggle, packed with withdrawal symptoms, including nausea, fatigue, and insomnia.
The user decided to take a break from Phenibut following this experience, although they were undecided on whether or not they would use it again in the future.
Review #2: Uncommon Review of Positive, Every Day Use
One LongeCity user posted about one of the more unique and promising experiences with using Phenibut for chronic anxiety.
Prior to Phenibut supplementation, this user had experienced debilitating anxiety for their whole life, even after seeking treatment and medications. At this point, they decided to give Phenibut a chance. They began at 0.5 g/day, and slowly increased to 2 g/day every day. This user experienced a complete turnaround of their life, both professionally and personally. They went back to college, began working out regularly, made new friends, and finally felt in control.
Rather than needing to increase the dose past 2 g, this user felt that they reached their peak threshold, experiencing negative side effects like drowsiness only if more was taken. In order to test dependence and withdrawal, they gave it up through tapering down for one month. The withdrawal was difficult, and once the withdrawal symptoms went away, they felt as though they were the exact same anxious person that they were before starting Phenibut.
The user then went back to 2 g/day daily Phenibut for the next six months, and regained control of their stress and anxiety. They point out that they examined the risk of long-term use with the benefits of present day health and happiness, and for them this tradeoff made sense. Other medications, such as antidepressants, build tolerances too. These drugs would also necessitate tapering if needing to stop, however the struggles with anxiety and depression can be large enough for some to view this risk as a chance they are willing to take.
This user is unique in not feeling the effects of Phenibut decrease after prolonged use.
Review #3: First Time Experience
One Reddit user shared their positive experience with taking Phenibut over the course of one day. They took 750 mg on an empty stomach at 2pm. Over the next four hours they felt an increase in their libido and interest in conversation and music. This was paired with a reduction in anxiety and a “body high.”
They then took 250 mg more Phenibut and felt lethargic, heavy, and not quite as talkative for about an hour. Shortly after that, the energy and social interest returned, where they then chose to take 250 mg more. At this point the feelings transitioned to a more chill mood, with most of the effects gone at 11 pm, three hours after their last 250 mg dose.
Review #4: Regular User Twice Per Week
This Reddit user reported their effects with dosing Phenibut only 2 times per week with minimal breaks for over three years. They take 2 g/day and have taken this same dose more-or-less this whole time. From time-to-time they will do a lower dose of 1.5 grams for a few doses, and then go back up to their normal dose and feel the effect more strongly.
Other users on this thread reported similar styles of dosing and experiences, with very little to no tolerance buildup and continued positive effects.
Review #5: Scary Megadose Experience
One Reddit user accidentally took more Phenibut than they had intended on, taking 4 grams at one time. The story of the next 24 hours is alarming and a good warning as to why you want to be very careful when dosing this drug.
For 6 hours he was having a good time, but then passed out, face down on his keyboards, for 15 hours until his girlfriend came home and woke him up. That day he experienced a blackout where he had no memory, muscle spasms, visual distortions similar to having a migraine, extreme fatigue, and numbness.
He feels that he may have nearly killed himself through an overdose, as the feelings he experienced were very similar to when he did overdose on opiates in the past.
Things to Consider Before You Take Phenibut
Even though Phenibut is used successfully in nootropic stacks, you need to be careful of dangerous combinations. Combining it with certain anxiolytics or alcohol is not recommended. There are other side effects that you will want to be careful of, including the risk of tolerance and withdrawal.
While many have found success with this nootropic, there are others who have had different experiences. User reviews of Phenibut can help you learn what to expect, along with experiences of a variety of Phenibut stacks.
Be sure to buy Phenibut supplements only through a reputable source, as some products on the market may not be what they claim. Pure Nootropics and Nootropics Depot are two online vendors that offer quality products and competitive prices.
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