STATUS: RUO / FDA CAT. 2 / WADA S0
Legal KLOW
A regulatory reading room for the KLOW four-peptide research blend — FDA, WADA, DEA, and 503A status, source-linked.
The regulatory position in plain language
KLOW is a four-peptide research blend — GHK-Cu, BPC-157, TB-500, and KPV — sold in a single laboratory vial. None of the four components is FDA-approved for human use. As of September 2023, injectable GHK-Cu, BPC-157, KPV, and the Thymosin Beta-4 fragment are all in FDA Category 2 of the 503A Bulks List, meaning licensed US compounding pharmacies cannot lawfully prepare them for patients. BPC-157 is additionally named on the WADA Prohibited List (category S0), a catch-all that covers the other three components by the same definition. The DEA has not scheduled any of the four. This site summarizes the public regulatory record — FDA notices, WADA listings, peer-reviewed studies, court filings — with every claim linked to its primary source. It does not sell anything, give legal advice, or recommend any use. For what the blend's components may do and who has reason to be careful, see the reported effects page.
What KLOW is, in one paragraph
KLOW is a vendor-prepared research peptide blend. A typical 80 mg vial contains GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg, and KPV 10 mg — four peptides with distinct mechanisms and four separate regulatory postures, packaged together for laboratory research. There is no published controlled trial of the combination, no FDA approval for any component, and no pharmacopeial monograph that defines the four together as a drug product [05][08][12]. Every claim on this site is attributed to a primary source. None of it is medical advice. None of it is legal advice.
The four components and their regulatory standing
Each KLOW component carries its own status. GHK-Cu (CAS 49557-75-7) is a copper-tripeptide originally isolated from human plasma in 1973; its injectable form was placed in FDA Category 2 of the Interim 503A Bulks List in September 2023, while topical GHK-Cu remained in Category 1 with restrictions [05][12]. BPC-157 (CAS 137525-51-0) is a synthetic 15-amino-acid pentadecapeptide derived from a gastric-juice protein; it was placed in FDA Category 2 in the same 2023 update and is explicitly listed on the World Anti-Doping Agency Prohibited List under category S0 [05][12]. TB-500 (CAS 77591-33-4) is a synthetic 17-residue fragment marketed as an analog of Thymosin Beta-4; the FDA's 2023 action specifically named the Thymosin Beta-4 fragment LKKTETQ in its Category 2 placement [05][12]. KPV (CAS 67727-97-3) is the C-terminal tripeptide of alpha-MSH; it was also placed in FDA Category 2 in the 2023 update [05][09][12]. None of the four are scheduled under the US Controlled Substances Act [12].
What 'Category 2' actually means
The FDA's Interim Policy on Compounding Using Bulk Drug Substances sorts ingredients into three categories. Category 1 substances may be compounded under the interim policy. Category 2 substances may not — the agency has identified what it calls 'significant safety risks,' which in the case of the peptides above included concerns about immunogenicity, peptide-related impurities, and limited human safety data [05][12]. The September 29, 2023 update placed BPC-157, KPV, injectable GHK-Cu, and the LKKTETQ Thymosin Beta-4 fragment into Category 2, with the result that a licensed US 503A compounding pharmacy cannot lawfully compound any of these substances for a patient [05][12]. The Category 2 designation is the load-bearing fact behind every 'is KLOW legal' question, and it is the reason this site exists as a reading room rather than a buyer's guide.
What this site does and does not do
Legal KLOW is an independent editorial project. It summarizes the public regulatory record on the four KLOW components and links each claim to its primary source — FDA notices, WADA listings, peer-reviewed studies, court filings, and the relevant clinical-trial registries. It is not a law firm. It is not a medical practice. It does not import, distribute, or compound any of the substances discussed. Information here is descriptive — the regulatory record as it stands — and is offered for research and educational reading only [12].
Sport, service, and the WADA S0 question
For athletes in WADA-signatory sports and for US service members covered by the Department of Defense's Operation Supplement Safety program, the framework is sharper than the general FDA picture. BPC-157 is explicitly listed on the World Anti-Doping Agency Prohibited List under category S0 (Non-Approved Substances), prohibited at all times in and out of competition [12]. Category S0's catch-all language — any pharmacological substance not currently approved by any governmental regulatory health authority for human therapeutic use — covers GHK-Cu, the TB-500 fragment, and KPV by the same definition. The US Anti-Doping Agency has issued a public advisory on BPC-157, and the DoD's OPSS program has issued a parallel advisory to service members [12]. Multiple sanctions have been issued on BPC-157 alone.
Where to read next
The /research page walks through each component's mechanism and the studies that anchor the regulatory conversation. The /dosage page summarizes the research-context dose ranges that have appeared in the published literature. The /faq page answers the fourteen questions readers most often arrive with, including 'Is KLOW WADA-prohibited?' and 'Can a compounding pharmacy legally make KLOW?' The /references page lists every source cited on the site with DOI and PubMed links. The /about page is explicit about what this site is — an independent editorial reading room — and what it is not. The reading is dense in places; that is intentional. Regulatory questions about research peptide blends are not well served by a paragraph of bullet points.