Across all trials, the side effect profile of AOD 9604 was described as indistinguishable from placebo
The balanced collagen synthesis and counteracted hepatic fibrosis (considered as a model of the wound-healing response to chronic liver injury), are along with BPC 157s particular interaction with several molecular pathways (Tkalcevic et al., 2007
This is encouraging but limited - animal results do not always carry over to humans, and this is one study, not a body of evidence
But the reason that athletes like it is because it's thought to reduce inflammation and improve blood flow and perhaps do even more
It is being studied in models of rheumatoid arthritis, COPD, Crohn's disease, and pulmonary fibrosis.Delgado et al., Pharmacol Rev 2004)