Compare prices and buy Phenibut FAA from 1 research peptide vendor - also called suppliers or sources. Updated daily.
The free amino acid form of phenibut (beta-phenyl-gamma-aminobutyric acid), the same active compound as Phenibut Hydrochloride without the hydrochloride counterion. Because the salt's mass includes the counterion, a milligram of the free form carries more phenibut than a milligram of the hydrochloride. Once dissolved, both deliver the same GABA-B receptor agonist, with the same reports of dependence and withdrawal. It is not FDA-approved, and FDA warning letters have named both forms among products treated as unapproved new drugs.
For research purposes only. Not medical advice.
Phenibut FAA is not a peptide. It is the free amino acid form of phenibut, beta-phenyl-gamma-aminobutyric acid, the same compound sold as Phenibut Hydrochloride without the hydrochloride counterion. PeptideScouter catalogues it under Nootropic & Neurological for the same reason as the salt: the research-peptide vendors it indexes sell it alongside their peptides, with which it shares no chemistry.
The hydrochloride page carries everything the two forms share, starting with the dependence and withdrawal reports, then the receptor pharmacology, the clinical history in Russia and the US regulatory record. This page covers only what differs between the forms.
The two formulas differ by one hydrogen chloride, which accounts for the 36.45 difference in molecular weight. Dividing the weights gives the mass ratio: phenibut makes up 179.22 / 215.67, about 83.1%, of the hydrochloride's mass. Read the other way, a milligram of the free form carries about 20% more phenibut than a milligram of the hydrochloride.
"Free amino acid" in a vendor title is a chemistry descriptor. It names the compound without a counterion.
A label milligram on a hydrochloride listing counts the salt unless the listing says otherwise. The same label figure on the two rows therefore describes different amounts of phenibut, and a per-milligram comparison between them is like-for-like only after the hydrochloride's milligrams are converted to free acid.
PeptideScouter computes no per-milligram price for either row. It calculates one only for vials labelled by mass, and as of October 2026 PeptideScouter's Phenibut FAA listings are bulk powder sold by the gram, so they appear in the price table but on no per-milligram ranking.
Drugs@FDA returns no application for phenibut as of October 21, 2026, so neither form has FDA approval. Two points in FDA's record bear on the free form specifically.
The Federal Food, Drug, and Cosmetic Act counts amino acids among dietary ingredients, but FDA's phenibut page states that phenibut "does not fit any of the categories of dietary ingredients" and that supplements declaring it are misbranded. A July 2021 warning letter made the same point about the salt, saying phenibut HCl does not qualify because it is not "a vitamin, mineral, amino acid, herb or other botanical" or any other listed type.
The rest of the record, including the other warning letters and the compounding lists, is on the hydrochloride page.
Phenibut FAA is the free amino acid form of phenibut, C10H13NO2 with a molecular weight of 179.22. Phenibut HCl is the hydrochloride salt, C10H14ClNO2 at 215.67. They are the same active compound, and the salt's extra mass is the hydrochloride. A milligram of the free form therefore carries about 20% more phenibut than a milligram of the hydrochloride, so a per-milligram figure on one form is not directly comparable to the other. PeptideScouter indexes the two forms as separate rows.
Not according to FDA. The Federal Food, Drug, and Cosmetic Act counts amino acids among dietary ingredients, but FDA's phenibut page states that phenibut does not fit any of the categories of dietary ingredients, so dietary supplements that declare it are misbranded. A November 2021 FDA warning letter named Phenibut FAA products, alongside phenibut HCl products, among those it treated as unapproved new drugs. Neither form has FDA approval.
PeptideScouter computes a price per milligram only for vials labelled by mass. As of October 2026, PeptideScouter's Phenibut FAA listings are bulk powder sold by the gram rather than vials, so they appear in the price table but on no per-milligram ranking. The hydrochloride listings, capsules and bulk powder, show no per-milligram price either.
Phenibut FAA is sold by 1 research peptide vendor indexed on PeptideScouter, with 1 tracked listing compared per vendor in the table above. Pricing is normalized and refreshed daily.
All 1 indexed research peptide vendor currently have Phenibut FAA in stock. Stock state is refreshed daily from each vendor's catalog.
Discount codes are issued per vendor rather than per peptide, so any code applies across that vendor's whole catalog. All 1 vendor listing Phenibut FAA publish a PeptideScouter code, worth 10% off. These listings do not carry a comparable per-milligram price, so code availability is shown without a normalized effective price. Each vendor's code is shown beside its price in the table above.
1 research peptide vendor currently lists Phenibut FAA on PeptideScouter. We track 1 listing across size and kit variants.
Phenibut FAA's CAS Registry Number is 1078-21-3. It is also sold as Phenibut FAA, Phenibut Free Amino Acid.
