The actions of the stomach are an important first step in the digestion of the food that we eat. This occurs in part through mechanical grinding of large ‘clumps’ of food into smaller pieces for passage into the intestines. However, cells that line the stomach also secrete a number of compounds into the gastric cavity. These include hydrochloric acid (HCl), as well as a number of complex proteins and a few much smaller proteins known as peptides.
HCl is responsible for the initial degradation of ingested protein into smaller proteins and protein fragments. The final conversion of ingested protein into amino acids and very short peptides that can be absorbed into the bloodstream takes place in the intestines.
Conversely, some of the secreted gastric proteins, such as the mucins, are essential for protection of the stomach lining from the corrosive effects of the HCl. The mucins are large complex proteins that are heavily covered by sugar molecules and that coat the gastric mucosal cells with a viscous, gel-like layer (also known as mucous). Another important gastric secreted protein is pepsinogen, which is cleaved by the HCl into pepsin, an enzyme that assists in the digestion of dietary proteins. Finally, the gastric protein Intrinsic Factor plays an essential role in the absorption of Vitamin B12 into the body.
In contrast to the well-established gastric proteins, the stomach also releases a few, less-well understood peptides into the gastric juices. One of these is the family of “trefoil factor peptides.” The trefoils are peptides that are protected from degradation in the stomach by their complex, twisted structure. They play roles in the recovery of the gastric and intestinal cells from injury, they promote cell migration in order to close-off the site of an injury and they prevent leakage of the gastrointestinal contents into the bloodstream. However, a few studies have suggested that these actions of the trefoil peptides may also contribute to the movement of cancer cells, known as metastasis, in cell models. Indeed, trefoil peptides have been detected in a number of different types of tumours. When taken together, these findings highlight the need for caution in assuming that every compound that is produced by the body is ‘good’.
Another addition to the slurry of proteins that is released into the gastric contents is the protein originally named Body Protection Compound (BPC). BPC was first reported by Sikiric et al in the early 1990s in Russian journals that are not readily available to this author. A large protein, BPC was claimed in a 1994 US patent (#5,288,708) to have been isolated from both “human and animal gastric juice” and to exert a wide-range of protective effects in organ injury models. The patent gives exceedingly little information about the isolation process, stating only that a variety of relatively crude chromatographic approaches were utilized (i.e., ion-exchange and gel) followed by dialysis (i.e. removal of salts and other small molecules). It is therefore impossible to know whether the isolated BPC was, in any way, a pure isolate.
The tested animals that were listed in the patent include rats, mice, rabbits, guinea pigs and pigs, as well as a single study in humans. Altogether, the number of tissues in which BPC was claimed to be effective was staggering. The evidence was based on experimental data only briefly described in the patent and included models of: gastric ulcers, heart damage, liver damage, pancreatic injury, kidney damage, experimental diabetes, fever, edema, rhinitis, bone fracture, burns, skin wounds, hypersensitivity reactions, pupil dilation, colon injury, tumour growth, radiation injury, red blood cell development, fertility and lactation, tooth damage, several types of central and peripheral nerve damage, and survival from infection with Trichinosis (i.e., tapeworms) as well as several viruses. The single study in 10 men claimed that BPC improved sperm cell motility. In summary, based on some weak animal data and essentially with no human evidence, BPC was claimed to be the mythical ‘panacea for all ills’.
Subsequent studies and patents from the same group of researchers showed that a 15 amino acid peptide derived from the N-terminus of BPC, now known as BPC 157, has many of the same effects as the entire protein. The key feature of this short peptide is its high concentration of one specific amino acid, proline, that provides an unusual ‘kink’ in peptides and proteins and may delay or even prevent its degradation. Nonetheless, the discovery of this sequence has enabled the laboratory synthesis of this short peptide using a relatively-straightforward chemical process.
In addition to continuing reports from Sikiric et al, one group has shown that BPC 157 improves rat tendon growth using a cell model, while another group demonstrated that it is not toxic in dogs. A clinical trial for its use in hamstring injury is currently recruiting ().
To date, only 3 publications have reported on the administration of BPC 157 to humans. In 2021, Lee et all reported on a retrospective study in 16 patients who received injections of BPC 157 into their knee for the treatment of pain, either alone or in combination with another compound (Thymosin-beta-4). Six-to-12 months later, the patients were asked to recall if their pain had improved. This totally subjective study that lacked the necessary control group(s) concluded that, in 14 of the patients, ‘intraarticular injection of BPC-157 helps with multiple types of knee pain.” In a similar 2014 study that also lacked any controls, the same group reported that BPC 157 was effective in relieving the pain associated with interstitial cystitis (bladder pain) in 10 of 12 women. This group has also recently reported (2025) that intravenous administration of BPC 157 had no side-effects and was well-tolerated in two women.
So what is the current status of BPC 157? Despite a near-total lack of evidence that BPC 157 is effective or even safe for use in humans, this peptide is being touted for use to repair muscle, tendon and ligament damage in athletes, for recovery from surgery, and to improve gut health, amongst other indications. Now referred to as the ‘Wolverine Peptide’ for its purported regenerative properties, BPC 157 has become the latest darling of the gym. However, produced by unregulated compounding companies (the so-called ‘gray market’, and mainly originating from China), there is no guarantee that the purchased product even contains BPC 157, let alone other contaminants that might cause allergic or other adverse reactions. Indeed, BPC 157 use has not been approved by the US Food and Drug Administration, meaning that it cannot legally be prescribed or purchased in the USA. It is also listed as a prohibited agent by the US Department of Defense/War as well as by the World Anti-Doping Agency (WADA).
Finally, the long-term, whole-body effects of administering a peptide that is normally restricted to the stomach remain completely unknown. As an additional example to that of the trefoil peptides noted above, the peptide EGF (epidermal growth factor) is produced in human milk to promote growth of the gastrointestinal tract in newborn infants, but the same peptide aggressively stimulates the growth of breast cancer cells in adults. The only remaining question in this story is ‘why’? Why indeed would anyone take such a chance?
Patricia Brubaker, Ph.D., F.R.S.C., F.C.A.H.S. is a Professor Emerita, Departments of Physiology and Medicine at the University of Toronto, Toronto, ON, Canada. Dr. Brubaker completed both her undergrad and PhD at ɬ.
