BPC-157 is a natural protein found in the human stomach and digestive tract. Most proteins are broken down in the stomach and are reduced to their amino acid constituent parts -- which is why the oral delivery of protein drugs such as insulin has thus far been effectively impossible -- but BPC-157 is, surprisingly, highly stable and orally bioavailable. It has been surmised that it functions as an endogenous anti-ulcer agent and angiogenic growth promoter, and that its primary site of action is the digestive tract.
Yet supplementation with BPC-157 has been shown to improve overall wound healing , improve ligament healing , improve tendon healing and increase HGH receptor expression in recovering tendon injuries , accelerate muscle recovery from crush injuries , accelerate soft tissue recovery,  and more. In all cases, it was delivered orally
. It appears to mediate these effects by increasing growth factor expression -- e.g. HGH receptor expression -- at injury sites. [6, 7]
The "BPC" stands for body protection compound, and, true to its name, there's no more potent natural compound for tendon, ligament, and muscle recovery.
 Seiwerth, S., Milavic, M., Vukojevic, J., Gojkovic, S., Krezic, I., Vuletic, L. B., Pavlov, K. H., Petrovic, A., Sikiric, S., Vranes, H., Prtoric, A., Zizek, H., Durasin, T., Dobric, I., Staresinic, M., Strbe, S., Knezevic, M., Sola, M., Kokot, A., … Sikiric, P. (2021). Stable gastric pentadecapeptide bpc 157 and wound healing. Frontiers in Pharmacology, 12, 627533. https://doi.org/10.3389/fphar.2021.627533
 Cerovecki, T., Bojanic, I., Brcic, L., Radic, B., Vukoja, I., Seiwerth, S., & Sikiric, P. (2010). Pentadecapeptide BPC 157 (PL 14736) improves ligament healing in the rat. Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society, 28(9), 1155–1161. https://doi.org/10.1002/jor.21107
 Japjec, M., Horvat Pavlov, K., Petrovic, A., Staresinic, M., Sebecic, B., Buljan, M., Vranes, H., Giljanovic, A., Drmic, D., Japjec, M., Prtoric, A., Lovric, E., Batelja Vuletic, L., Dobric, I., Boban Blagaic, A., Skrtic, A., Seiwerth, S., & Predrag, S. (2021). Stable gastric pentadecapeptide bpc 157 as a therapy for the disable myotendinous junctions in rats. Biomedicines, 9(11), 1547. https://doi.org/10.3390/biomedicines9111547
 Novinscak, T., Brcic, L., Staresinic, M., Jukic, I., Radic, B., Pevec, D., Mise, S., Tomasovic, S., Brcic, I., Banic, T., Jakir, A., Buljat, G., Anic, T., Zoricic, I., Romic, Z., Seiwerth, S., & Sikiric, P. (2008). Gastric pentadecapeptide BPC 157 as an effective therapy for muscle crush injury in the rat. Surgery Today, 38(8), 716–725. https://doi.org/10.1007/s00595-007-3706-2
 Seiwerth, S., Rucman, R., Turkovic, B., Sever, M., Klicek, R., Radic, B., Drmic, D., Stupnisek, M., Misic, M., Vuletic, L. B., Pavlov, K. H., Barisic, I., Kokot, A., Japjec, M., Blagaic, A. B., Tvrdeic, A., Rokotov, D. S., Vrcic, H., Staresinic, M., … Sikiric, P. (2018). Bpc 157 and standard angiogenic growth factors. Gastrointestinal tract healing, lessons from tendon, ligament, muscle and bone healing. Current Pharmaceutical Design, 24(18), 1972–1989. https://doi.org/10.2174/1381612824666180712110447
 Gwyer, D., Wragg, N. M., & Wilson, S. L. (2019). Gastric pentadecapeptide body protection compound BPC 157 and its role in accelerating musculoskeletal soft tissue healing. Cell and Tissue Research, 377(2), 153–159. https://doi.org/10.1007/s00441-019-03016-8
 Chang, C.-H., Tsai, W.-C., Hsu, Y.-H., & Pang, J.-H. S. (2014). Pentadecapeptide BPC 157 enhances the growth hormone receptor expression in tendon fibroblasts. Molecules (Basel, Switzerland), 19(11), 19066–19077. https://doi.org/10.3390/molecules191119066