What are the potential side effects of BPC 157?

Potential concerns include increased growth of existing tumors, possible visible vascular changes, and substantial uncertainty about human safety. 1

• VEGF and blood-vessel growth: BPC-157 may increase VEGF and angiogenesis. That could support tissue repair, but might also provide blood flow and growth factors to an existing tumor, potentially helping it grow. 2
• Growth hormone receptors: BPC-157 may upregulate growth hormone receptors around an injury; if a tumor is present in that area, this could potentially accelerate its growth. 3
• Other possible effects: A physician’s personal observation of worsening facial angiomas was discussed, with increased angiogenesis offered as a plausible explanation. This is an anecdotal observation, not established evidence of a common side effect. 4
• Human safety remains unclear: Evidence is largely animal research and anecdotal reports; the discussion emphasizes the scarcity of rigorous human studies. A small phase-one trial of rectal BPC reported no adverse effects, but that does not establish the safety of other forms or broader use. 5 6
• Animal-dose findings and dosing context: One discussion described a very high animal LD50 estimate, while another noted that the LD50 is not known—so these reports do not establish safety in people. Typical use was described as 300–500 micrograms subcutaneously two or three times weekly for about eight weeks; that is reported practice, not a proven safe regimen. 7 8