Skin research
Collagen in cells
GHK-Cu and collagen production — Maquart and colleagues, FEBS Letters, 1988. GHK-Cu increased collagen production in cultured fibroblasts, cells that make supporting tissue. This wasn't a trial of skin appearance in people.
Topical cosmetic findings
GHK and skin regeneration — Pickart, Vasquez-Soltero and Margolina, BioMed Research International, 2015. This review reports topical cosmetic findings from sources including a conference presentation, a university report and a book chapter. Those are limits on how directly the underlying methods and results can be checked. Results for products applied to skin don't establish benefits from a GLOW injection.
Getting through the skin barrier
Topically applied GHK — Mortazavi, Mohammadi Vadoud and Moghimi, BioImpacts, 2025. The review discusses poor passage across the outer skin barrier and the shortage of clinical studies. It asks about topical products, not the blend.
Repair research and its limits
Injured rats
BPC-157 in rat Achilles-tendon healing — Staresinic and colleagues, Journal of Orthopaedic Research, 2003. Researchers cut rats' tendons and measured healing, including strength and function. An animal result doesn't establish human recovery benefits.
A very small human safety report
An intravenous BPC-157 safety pilot — Alternative Therapies in Health and Medicine, 2025. Two adults had no reported side effects or measurable changes in the organ-function markers tested. The report didn't test GLOW or establish a safe range.
TB-500's identity and evidence gap
FDA's TB-500 assessment — U.S. Food and Drug Administration, 2026. This distinguishes the fragment from full-length thymosin beta-4 and records the lack of published human TB-500 administration studies. Those limits come before any borrowed claim about the full protein.
Eye drops of the full protein
A thymosin beta-4 dry-eye trial — Sosne and Ousler, Clinical Ophthalmology, 2015. Neither main planned outcome improved significantly compared with the control group; some secondary measures did. The substance was full-length thymosin beta-4, not TB-500.
Blood-vessel growth in experimental models
BPC-157 and blood-vessel signalling — Hsieh and colleagues, Journal of Molecular Medicine, 2017. The work used chick-egg, rat and human-cell models. It helps explain a theoretical question about cancer; it did not test cancer risk in people receiving BPC-157 or GLOW.
FDA status, safety and reporting
FDA's peptide safety-risk page — content current as of April 22, 2026. The withdrawn-nomination table retains safety concerns. Withdrawal isn't clearance, and FDA gives no per-substance withdrawal dates.
FDA's substance category list — updated May 14, 2026. The non-injectable GHK-Cu entry is separate from the injectable entry. A category listing isn't product approval.
FDA's compounding questions and answers explains why compounded medicines are not FDA-approved. FDA doesn't verify their safety, effectiveness or quality before marketing.
MedWatch is FDA's medical-product safety reporting program for patients, consumers and health professionals. Reporting a concern is separate from getting medical care.