BPC‑157 is a tiny peptide found in stomach juice that appears to protect many organs from damage. In animal studies it works at very low doses (micrograms or nanograms per kilogram) when given by injection, orally, or directly to the gut, and it shows benefits even when given after injury. No obvious side effects or toxicity were reported, but the exact way it works is still unclear.

The possibility that the stomach, affected by general stress, might initiate a counter-response has not until recently been considered in theories of stress. We suggest that the stomach, as the most sensitive part of the gastrointestinal tract and the largest neuroendocrine organ in the body, is crucial for the initiation of a full stress response against all noxious stress pathology. The end result would be a strong protection of all organs invaded by 'stress'. Consistent with this assumption, this coping response is best explained in terms of 'organoprotection'. Endogenous organoprotectors (eg prostaglandins, somatostatin, dopamine) are proposed as mediators. Such an endogenous counteraction could even be afforded by their suitable application. A new gastric juice peptide, M(r) 40,000, named BPC, was recently isolated. Herein, a 15 amino acid fragment (BPC 157), thought to be essential for its activity, has been fully characterized and investigated. As has been demonstrated for many organoprotective agents using different models of various tissue lesions, despite the poorly understood final mechanism, practically all organ systems appear to benefit from BPC activity. These effects have been achieved in many species using very low dosages (mostly microgram and ng/kg range) after ip, ig, and intramucosal (local) application. The effect was apparent already after one application. Long lasting activity was also demonstrated. BPC was highly effective when applied simultaneously with noxious agents or in already pathological, as well as chronical, conditions. Therefore, it seems that BPC treatment does not share any of the so far known limitations for 'conventional organoprotectors'. No influence on different basal parameters and no toxicity were observed. These findings provide a breakthrough in stress theory. BPC, as a possible endogenous free radical scavenger and organoprotection mediator, could be a useful prototype of a new class of drugs, organoprotective agents.