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What Published Research Has Examined: A Reading Guide for Four Studied Compounds

A reading guide to published research on BPC-157, TB-500, GHK-Cu and NAD+: which models were studied and at what stage, with a source for each point.

Updated October 5, 2026

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This article is a reading guide to the published literature: what kinds of studies exist, in which models, and at what stage. It does not summarize outcomes as recommendations.

BPC-157

BPC-157 is a synthetic 15-amino-acid peptide. Researchers at the University of Zagreb described it in 1993 as a fragment of a protein isolated from gastric juice (Sikiric et al., 1993). Most of the published work is preclinical. A 2025 systematic review in HSS Journal included 36 studies, of which 35 were preclinical and one was clinical, and reported that it found no clinical safety data (Vasireddi et al., 2025). Reuters reported on 15 September 2026 that the FDA had previously restricted compounding of BPC-157, citing what it described as significant safety risks and insufficient human data. The same report said an FDA advisory committee voted in July 2026 to allow compounding, and that the FDA had not yet issued its decision (Reuters via Medscape). In short: a large animal literature and a very small human one.

TB-500 (thymosin beta-4 fragment)

Thymosin beta-4 is a naturally occurring protein described in the literature as the major G-actin-sequestering molecule in mammalian cells, with published work on its role in cell migration. A 2010 review by authors from RegeneRx Biopharmaceuticals describes clinical trials of the full-length protein sponsored by that company (Crockford et al., 2010). In 2012, a doping-control laboratory at Ghent University identified the N-terminal acetylated 17-23 fragment of thymosin beta-4 (Ac-LKKTETQ) in a product called TB-500 (Esposito et al., 2012). Material sold under that name is therefore not the same molecule as the full-length protein studied in those trials. Speaking about grey-market peptides including BPC-157 and TB-500, Professor Adam Taylor of Lancaster University told BBC News that the available data come from pre-clinical models.

GHK-Cu

GHK (glycyl-L-histidyl-L-lysine) is a tripeptide first reported in human serum in 1973 (Pickart and Thaler, 1973). GHK-Cu is its copper complex. A 2018 review in the International Journal of Molecular Sciences surveys laboratory work on dermal fibroblasts, collagen and elastin synthesis, and gene-expression data (Pickart and Margolina, 2018). BBC News reported in March 2026 that GHK-Cu is used topically in skin creams (BBC News).

NAD+ and its precursors

NAD+ (nicotinamide adenine dinucleotide) is not a peptide. It is a coenzyme involved in many cellular processes, including energy metabolism (Covarrubias et al., 2021). It is included here because research catalogs often list it alongside peptides. Unlike the entries above, the NAD+ precursors nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) have been studied in randomized human trials, for example in middle-aged and older adults (Martens et al., 2018) and in postmenopausal women (Yoshino et al., 2021). A central question in these trials is whether the precursors change NAD+ levels. A 2023 review in Science Advances assessed 25 published human studies of NR and concluded that few clinically relevant effects had been shown (Damgaard and Treebak, 2023). Regulatory status has also shifted: the FDA said in November 2022 that NMN was excluded from the definition of a dietary supplement because it had been authorized for investigation as a new drug, and it reversed that position in September 2025 in response to a citizen petition (NutraIngredients, 30 September 2025).

How to read this literature honestly

Three questions separate serious reading from hype: (1) Was the study in humans, animals, or cells? (2) Was it peer-reviewed and indexed, or a preprint or poster? (3) Who funded it? Most research-peptide literature is preclinical. That does not make it worthless; it makes it research, which is precisely the frame these materials are sold under.

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Photo: Jeff Sheldon / Unsplash

Sources

This article is a summary of publicly reported information for research-community awareness only. It is not medical advice, not legal advice, and not a statement about any BioLabs Research product.

For research use only. Not for human or veterinary use. Not a drug, food, or cosmetic.

This summary is for research-community awareness only and is not legal advice.

BioLabs Research has no affiliation with, and no endorsement from, any person named.

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