Phenibut (β-phenyl γ-aminobutyric acid) and kratom are becoming an increasingly popular nootropic stack of choice for treating anxiety, depression, and post-traumatic stress disorder (PTSD). While they are undoubtedly mind-altering and can be therapeutic, phenibut and kratom are problematic due to their high risk of substance abuse.
In fact, many of the "kratom bars" that had been cropping up in the United States are now kaput, and it's no longer legal to sell phenibut over-the-counter. (Of course, that hasn't stopped supplement companies from using either of these substances in their nootropic formulas.)
The U.S. Food and Drug Administration cracked down on phenibut and kratom quickly after receiving numerous reports of severe withdrawal and dependence [1, 2]. The FDA maintains that these substances are not approved for treating any medical conditions or mental disorders, and they may pose a significant health risk when used recreationally.
Additionally, phenibut does not meet the definition of a dietary ingredient under the Federal Food, Drug, and Cosmetic Act (FD&C Act). As such, any online retailer or supplement company that markets phenibut as a dietary supplement is misleading consumers.
Read on as this article details phenibut's rise to fame, how it works in the brain, and what makes it so addictive. (We will cover kratom in more detail in a separate article.)
Chemically speaking, phenibut is a derivative of the chief inhibitory neurotransmitter gamma-aminobutyric acid (GABA). GABA is known to play an important role in producing feelings of calmness and relaxation since it readily inhibits the actions of glutamate (an excitatory neurotransmitter).
Naturally, GABA supplements have increased in popularity as people figure it will help reduce anxiety and improve mood. However, taking pure GABA (orally) is an inefficient means of increasing GABA levels in the brain since it doesn’t readily cross through the blood-brain barrier (BBB).
This is precisely why phenibut has gained ground as a more potent GABA-targeting nootropic since its slightly modified chemical structure allows it to cross the BBB.
Once phenibut crosses into the brain, it actively binds to a subclass of GABA receptors called GABA-B. After binding to these receptors, G-proteins provide a liaison to open and close potassium-chloride ion channels in the plasma membrane of neurons. In turn, a membrane potential is created, which can inhibit the actions of glutamate. Alcohol works in a very similar manner.
Thus, phenibut mimics the effects of having an alcohol buzz and presents an attractive alternative to drinking for people who want to go out and socialize without getting inebriated (and dealing with a hangover the next day). Phenibut also has strong anxiolytic properties, making it a promising candidate medication to treat anxiety and depression .
While some relevant studies look directly at phenibut use, much of the research on GABA-B receptor agonism (activation) comes from the pharmaceutical compound baclofen (a chlorinated analogue of β-phenyl γ-aminobutyric acid). Since baclofen has identical physiological effects as phenibut, it's reasonable to extrapolate research findings to the latter.
To give an example of just how effective GABA-B agonists are at calming the mind, a study in 2007 by Lhullier et al. treated hyperactive rodents (induced by cocaine administration) with baclofen and looked for changes in locomotion (movement) . (Yes, this study actually examined the activity of coked-out rodents, pretty amazing what scientists come up with these days.)
The findings were that baclofen led to a significant dose-dependent decrease in locomotor activity of rodents (despite being high on cocaine). In other words, a nootropic like phenibut can take the edge off of very potent stimulants. (Let’s just hope you’re not relying on phenibut to ease cocaine-induced jitters.)
Furthermore, for people who struggle with sleep issues like insomnia, phenibut appears to be quite effective. A 2009 study by Cui et al. found significant reductions in time spent awake and the time it took to fall asleep in physically stressed rats given baclofen . As such, using phenibut before bed may be prudent for treating insomnia and other sleep disorders.
A final noteworthy study completed in 2010 by Thomas et al. monitored the effects of baclofen on human thenar motor unit behavior ("thenar" refers to a group of muscles in the palm of your hand) . The results demonstrated that baclofen significantly increased the number of motor units necessary to produce one Newton of force; in non-nerd lingo, phenibut can decrease your muscle tone (i.e., make your muscles less tense), which is conducive to relaxation.
In short, the most pertinent benefits derived from phenibut use may include:
It's inadvisable to take phenibut daily, especially if you lack self-control or have a history of substance abuse. Intermittent use of phenibut in small doses will reduce the risk of adverse effects and addiction. Doing so will also help you avoid the dreaded “phenibut withdrawal” that comes from chronic use.
But again, phenibut is more or less a "street drug" now that the FDA has deemed it an adulterant in dietary supplements. There are next to no regulatory measures in place to ensure that the phenibut purchased online is actually phenibut.
It’s also important to note that baclofen is much more potent than phenibut, so the two are not interchangeable dose-wise. Anecdotal evidence suggests that a proper starting dose of phenibut is 10 mg per kilogram of body mass.
If you’re against the metric system, like the United States government, here’s a sample calculation:
This dose can be increased to 20-30 mg/kg of body mass if you don’t feel the effects at lower doses, but be aware that side effects and withdrawal symptoms are more severe as the dose increases.
As far as the timing of phenibut goes, it's best to consume it a few hours before intended periods of inactivity or down-time. Phenibut has a half-life between 5-6 hours, but it is slowly metabolized and may take 3-4 hours to exhibit its peak effects. Also, taking phenibut with food will slow the absorption rate, so consider that if you ingest it with a meal.
As aforementioned, there have been case reports of individuals that ingest rather large daily doses of phenibut going through withdrawal upon cessation of its use . To be fair, the individuals were using upwards of 10 grams of phenibut per day and not cycling their use. (In other words, they developed chronic phenibut dependence.)
Some side effects commonly associated with increased GABA levels are:
It is unlikely that a nominal dose of phenibut taken up to four times per week will incur withdrawal symptoms, let alone any other side effects. However, using phenibut for more than two consecutive days, particularly in doses exceeding 50 mg/kg of body mass, will increase the risk of dependence/addiction and subsequent withdrawal.
In the most severe cases, phenibut abuse can lead to psychotic withdrawal symptoms and suicidal ideation .
If you're currently taking (or planning on taking) phenibut or kratom for recreational purposes or to treat a mental health disorder, be mindful of the consequences. There's no shortage of anecdotes you can find online from people who have battled phenibut dependence and severe withdrawal. The same goes for kratom.
Phenibut and kratom are addictive substances with withdrawal symptoms that can make a person's mental health much worse. While they do have the potential for treating post-traumatic stress disorder, anxiety, and depression, they pose a high risk for substance abuse. And unfortunately, quitting phenibut and kratom cold turkey can be very challenging once you become dependent on them. In some cases, addiction treatment may be prudent.
We strongly recommend starting with nootropics that have significantly better safety profiles than phenibut, such as phosphatidylserine, NeuroFactor™, and Infinergy™, found in Transparent Labs Nootropic.