The short answer is that nobody knows, because nobody has measured it properly. The three human reports of BPC-157 describe 30 people and report no adverse events. None of them had a comparison group, and none followed anyone long enough to see a delayed effect. Animal studies report no toxicity, which is a different claim from safety in people.
What those human reports tested for benefit is laid out in what human evidence exists for BPC-157. This page reads the same record for harm.
What the human reports recorded
In a pilot of 12 women with interstitial cystitis, each received a total of 10 mg injected around the inflamed area of the bladder during one procedure [1]. No one dropped out and no adverse events were reported. In an intravenous pilot, two adults received 10 mg and then 20 mg on consecutive days [2]. Their heart, liver, kidney, thyroid and glucose markers did not change, and neither reported side effects.
A 2025 systematic review of the musculoskeletal literature found no clinical safety data at all [3]. It lists three reasons adverse effects remain possible: unregulated manufacturing, contamination, and simply unknown safety in people. A second 2025 review reached the same place, noting no adverse effects in three pilots but no large trials to measure any [4].
What the FDA says could go wrong
When BPC-157 was nominated for compounding, the FDA reviewed it and published a summary of its concerns [5]. It states that compounded BPC-157 may pose a risk of immunogenicity, meaning an immune reaction to the peptide, for certain routes of administration. It also flags complexities with peptide-related impurities and with characterizing the active ingredient. The agency says it lacks sufficient information to know whether BPC-157 would cause harm in humans.
Those are not side effects anyone has measured. They are the reasons the agency could not conclude the drug was safe to compound. BPC-157 now sits on none of the FDA’s 503A lists, which is why this site covers it as research only, under the recovery goal.
On July 23, 2026, the FDA’s Pharmacy Compounding Advisory Committee discussed BPC-157 for the 503A bulks list [8]. The FDA’s own briefing document concluded that the balance of criteria weighs against listing it, finding the substance not well characterized [9]. The committee voted 8–6 to recommend listing it anyway, with one abstention [10]. The vote does not bind the FDA, and a listing would still need notice-and-comment rulemaking, so BPC-157 remains on no list.
Risks the reviews raise
Two 2026 reviews of unapproved peptides list further concerns. A review in a state medical journal names product contamination, manufacturing impurities, inaccurate dosing and pathological angiogenesis among the risks of unapproved injectable peptides, BPC-157 included [6]. A sports-medicine review concludes that rigorous human safety data are scarce for the unapproved peptides and that serious harm is possible [7].
The angiogenesis concern follows from the mechanism. Animal work describes BPC-157 promoting new blood-vessel growth through the VEGFR2 and nitric oxide pathways [4]. That is the proposed route to faster healing, and the same process is why reviewers raise a theoretical question about tissue where new vessel growth is unwanted. No human study has tested it either way.
The unanswered questions
No study has reported what happens with repeated injections over months. No study has measured antibodies against the peptide. No study has checked interactions with other drugs. The first randomized, placebo-controlled trial, in hamstring strain, was recruiting at its last registry update and has not reported.
The same gaps apply to TB-500, covered in what is known about TB-500. For how this site separates a measured harm from a theoretical one, see the methodology.