Tell me more about BPC 157 and Thymosin beta 4.

BPC-157 and thymosin beta-4 (including the related TB-500) are experimental peptides discussed for tissue repair; animal findings are more substantial than the evidence available in humans. 1

• BPC-157 and angiogenesis: Animal studies suggest it can promote repair by encouraging new blood-vessel formation, including through VEGF signaling, and by supporting cell migration. How it works in people—and whether the animal effects translate—is not established. 2 3
• Administration and evidence: It is commonly injected under the skin or into muscle; some users inject near an injury. Whether local injection works better than systemic administration is not established, and reports of benefit are largely anecdotal; rigorous human evidence is very limited. 4 5
• Tumor-growth concern: Because BPC-157 may increase VEGF and blood-vessel growth, stimulating angiogenesis could theoretically support tumor growth. The concern is mechanistic; the discussion also notes that human risks remain uncertain. 6 7
• Thymosin beta-4 and TB-500: TB-500 is described as a shortened version of thymosin beta-4. Animal research links these peptides to wound repair and tissue remodeling, including stem-cell proliferation; the discussion says they are not thought to act through growth-hormone pathways. 8 9
• Human evidence for thymosin beta-4: Positive reports exist, but without clinical trials it remains unclear whether or how these peptides improve healing in people; the reported benefits are anecdotal. 10