KLOW Peptide Blend: What It Is and Its U.S. Status

What is the KLOW blend?

KLOW is a marketing name, not a scientific or regulatory term. It is commonly used for a blend of four separate peptides: BPC-157, TB-500, GHK-Cu and KPV. The blend is not FDA-approved, none of the four peptides is an FDA-approved drug, and no approved medicine in the United States contains the blend.

Blends sold under this name are not standardized. The amount of each peptide, and whatever else a vial contains, can vary from seller to seller, and the FDA does not review these products.

What is in the blend?

• BPC-157: a synthetic 15-amino-acid peptide based on part of a protein found in human gastric juice. BPC stands for body protection compound.
• TB-500: a synthetic peptide based on the central actin-binding region of thymosin beta-4, a protein found in most human cells.
• GHK-Cu: a three-amino-acid peptide (glycine, histidine and lysine) bound to copper. It occurs naturally in human blood and is widely used as a cosmetic ingredient in skin care.
• KPV: a three-amino-acid peptide (lysine, proline and valine) that matches the end of alpha-melanocyte-stimulating hormone (alpha-MSH).

What does the research say?

Each of the four peptides has been studied mainly in cells and animals. We found no published clinical trial of the four used together, so the safety of the combination in people has not been established.

For BPC-157, a 2025 systematic review in the HSS Journal found 36 eligible studies in musculoskeletal medicine, of which 35 were preclinical and one was clinical. For TB-500, the FDA has stated that it identified no human exposure data for drug products containing this thymosin beta-4 fragment.

U.S. regulatory status

Current status: Not FDA-approved.

The FDA has not approved the blend or any of its ingredients as a drug. The four peptides are at different points in the FDA's review of substances for pharmacy compounding:

• BPC-157, TB-500 and KPV: removed on April 15, 2026 from Category 2, the FDA's list of bulk substances that raise significant safety concerns, after their nominations were withdrawn. On July 23, 2026, the Pharmacy Compounding Advisory Committee voted 8 to 6, with 1 abstention, to recommend each one for the 503A Bulks List. FDA staff had recommended against them.
• GHK-Cu: the form given by needle was removed from Category 2 in April 2026 after its nomination was withdrawn. GHK-Cu for all other routes was placed back in Category 1, substances under evaluation, in May 2026. The FDA plans to consult the advisory committee on GHK-Cu before the end of February 2027.

The committee's votes are advisory only, and it reviewed each peptide on its own, not the blend. As of late September 2026, the FDA had not added any of these peptides to the 503A Bulks List. Even if it does, that would allow compounding with a prescription; it would not make them FDA-approved drugs.

Products sold online as research chemicals are not approved medicines, and the FDA has not reviewed their contents, purity or quality.

Sport

Under the World Anti-Doping Agency (WADA) 2026 Prohibited List, BPC-157 is named under class S0 (non-approved substances), and thymosin beta-4 derivatives such as TB-500 are named under class S2. Both are prohibited at all times. GHK-Cu and KPV are not named on the list.

Why Peptide Labs does not sell the KLOW blend

Peptide Labs does not sell this compound. This page is general information, not medical advice. We do not supply, prepare or distribute the KLOW blend in any form, and nothing on this page should be read as an offer.

If you have questions about the KLOW blend or a related health concern, talk to a licensed healthcare provider who knows your medical history.

Related reading

See the full list of compound profiles in the Peptide Guide. Each ingredient has its own profile: BPC-157, TB-500, GHK-Cu and KPV. See also the two-peptide BPC-157 and TB-500 blend.