β-Phenyl-γ-aminobutyric acid (also known as Fenibut, Phenybut, Noofen, Citrocard, and commonly as Phenibut) is a depressant substance of the gabapentinoid class.Phenibut acts as a receptor agonist for GABA, the major inhibitory neurotransmitter in the brain. It is chemically related to baclofen, pregabalin, and gabapentin.
Phenibut was developed in the Soviet Union in the 1960s, where it has been used as a pharmaceutical drug to treat a wide variety of conditions, including post-traumatic stress disorder, anxiety, depression, asthenia, insomnia, alcoholism, stuttering, and vestibular disorders, and others.In the rest of the world, phenibut is not approved for clinical use and is instead sold as a nutritional supplement.
There are three forms of phenibut:Phenibut FAA, Phenibut HCL, F-Phenibut，so what are the differences?
From the physical appearance,Phenibut hcl is White crystalline powder,phenibut hcl form is to handle due to its crystallizes easily and has excellent water solubility. On the downside, dissolved Phenibut HCl is highly acidic, sour/metallic to taste.
It is also irritating to mucous membranes and damaging to tooth enamel – causing it to be unsuitable for sublingual administration. Even when completely pure, Phenibut HCl is only approximately 83% Phenibut molecules by weight, with the other 17% being HCl. Phenibut HCL is the hydrochloride salt form of Phenibut, produced by reacting free Phenibut (the F.A.A. form) with hydrochloric acid.
Phenibut faa is the free amino acid form of Phenibut, It is close to neutral pH, making it very suitable for sublingual administration. Phenibut F.A.A. It has a mildly bitter taste and is moderately soluble in water. It is highly pure: more than 99.5% Phenibut molecules by weight (actually, no impurities at all are detectable by HPLC).
Phenibut FAA is a fine white powder and is, therefore, less dense than the crystalline HCl form (an equal mass of Phenibut F.A.A. occupies approximately twice as much volume as Phenibut HCL crystals). When consumed in the usual way, Phenibut F.A.A. is about 15% more efficient than Phenibut HCl, but otherwise has few advantages.
F-phenibut, F-Phenibut (Fluorophenibut) is a several-fold more potent derivative of Phenibut. Its chemical name is 4-Amino-3-(4-fluorophenyl)butanoic acid hydrochloride, White or off-white powder. Preliminary (unpublished) research tentatively suggests that F-Phenibut (Fluorophenibut) has a behavioral potency of approximately five to tenfold higher than Phenibut in vivo, with approximately sixfold higher affinity as a GABAB agonist than Phenibut, but may also retain comparable affinity and inhibitory efficacy at α2δ subunit-containing voltage-gated calcium channels, making F-Phenibut unique as an evenly balanced ligand for these two binding sites.
Comparing to the price, apparently phenibut hcl is more commonly used on the market and price is the cheapest.Phenibut faa’s price can be twice the cost of phenibut hcl,and F-phenibut is even more rare to find out on the market.