The honest answer on BPC-157 side effects is that nobody knows the full picture, because the peptide has barely been tested in people. A 2025 systematic review found 35 preclinical studies and one clinical study, and reported that “no clinical safety data were found”. BPC-157 is not an FDA-approved drug. It was previously in the FDA’s category 2 of compounding substances that may present significant safety risks; that nomination has since been withdrawn, but the FDA still publishes its safety concerns.
What BPC-157 is
BPC-157 is a synthetic chain of 15 amino acids. Researchers describe it as a partial sequence of a larger “body protection compound” originally isolated from human gastric juice. It is sold online as an injectable powder, a capsule or a nasal spray, usually with claims about tendon, gut or joint healing.
None of those claims has been tested in the way a medicine is tested before approval. A search of the FDA’s Drugs@FDA database returns no approved product containing BPC-157. The US Anti-Doping Agency states that “there are no human clinical trials establishing efficacy for the use of BPC-157 for any diagnosis or treatment”.
What the research actually covers
Most of what you read about BPC-157 traces back to cell cultures and rats. That work is real science, but it answers a narrow question: what happens in a dish or a lab animal under controlled conditions. It does not tell you what happens when a person injects a product of unknown origin.
| Type of study | Example | Size | What it can and cannot tell you |
|---|---|---|---|
| Cell culture | Rat tendon cells moved and spread faster, and survived chemical stress better, when exposed to BPC-157 (Chang, 2011) | Cells in a dish | Suggests a mechanism. Says nothing about safety or benefit in a living person. |
| Animal | Blood flow recovered faster and more vessels formed in rats with a blocked leg artery (Hsieh, 2017) | Rats | Shows an effect in rats. Rat results often fail to repeat in humans. |
| Systematic review | 36 studies on muscle, tendon, ligament and bone (Vasireddi, 2025) | 35 preclinical, 1 clinical | Confirms the evidence base is almost entirely animal and lab work. |
| Human, retrospective | Knee pain chart review with phone follow-up (Lee, 2021) | 16 patients | No control group, no standard pain scale. Cannot separate the peptide from placebo or time. |
| Human, uncontrolled pilot | Bladder injections for interstitial cystitis (Lee, 2024) | 12 women | No comparison group. Too small to detect uncommon harms. |
| Human, safety pilot | Intravenous infusion with blood tests (Lee, 2025) | 2 people | Both had received the infusion before. Two people cannot establish safety. |
| Registered trial | Phase 1 safety study in healthy volunteers (NCT02637284) | 42 planned | Status “unknown”; last updated in 2015, with no results posted. |
What the human reports do and do not show
Three small human reports exist, and they share important limits. All three list the same lead author, all appeared in the same journal, and all were run at private clinics, at least two of them in Florida. None used a placebo group.
In the knee study, 16 patients who had received knee injections were phoned months later and asked how much their pain had improved. The authors note that “no specific tools were used” to measure function or quality of life. Knee pain often changes on its own, which is why a comparison group matters.
The bladder study treated 12 women whose interstitial cystitis had not responded to standard treatment, and reported no adverse events. The intravenous study enrolled two adults who had both been given intravenous BPC-157 before, so neither was a first-time user.
A 2025 review by University of Utah physicians summed this up: only three pilot studies have examined BPC-157 in humans, “rigorous, large-scale trials are lacking”, and the peptide should be considered investigational.
BPC-157 side effects: known, possible and unstudied
“No adverse events reported” in 2, 12 or 16 people is not the same as “safe”. Small groups can miss side effects that are uncommon but serious, and none of these reports followed people for long enough to see slow-developing harms.
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Here is how the possible risks break down, and what each is based on.
| Possible risk | Where it comes from | What the evidence says |
|---|---|---|
| Immune reaction to the peptide | Injected peptides can trigger antibodies, especially when impure | The FDA says compounded BPC-157 “may pose risk for immunogenicity” for some routes. |
| Impurities and wrong content | Manufacturing outside drug regulation | The FDA lists “peptide-related impurities” and difficulty characterising the active ingredient. The 2025 systematic review lists unregulated manufacturing and contamination as sources of possible harm. |
| Effects of new blood-vessel growth | BPC-157 activates the VEGFR2 pathway in rats and human endothelial cells | Vessel growth helps healing in lab models (Hsieh, 2017). What this means in a person with an existing or undiagnosed tumor has not been studied. |
| Infection at the injection site | Non-sterile vials, home preparation, reused equipment | A risk of the injection, not the molecule. See our guide to peptide injection infections. |
| Long-term effects | No long-term human follow-up exists | Unknown. The FDA says it lacks sufficient information to know whether BPC-157 would cause harm in humans. |
BPC-157 and the FDA’s compounding rules
A compounding pharmacy can only make a drug from a bulk ingredient under certain conditions. Under section 503A, the ingredient must meet a USP or NF monograph, be a component of an FDA-approved drug, or appear on the FDA’s 503A bulks list, according to the FDA’s page on bulk drug substances.
The 503A bulks list in federal regulations currently names six substances, and BPC-157 is not one of them. BPC-157 was nominated for that list and reviewed by the FDA, which placed it in “category 2”, the group of substances that may present significant safety risks. It is no longer in that category.
The nomination was later withdrawn by the people who submitted it. As of April 2026, the FDA’s category 2 page lists BPC-157 among substances “previously in category 2” whose nominations were withdrawn. The safety statement still appears there: the agency “lacks sufficient information to know whether the drug would cause harm when administered to humans.”
The question is not closed. A Federal Register notice of April 16, 2026 scheduled the FDA’s Pharmacy Compounding Advisory Committee to discuss BPC-157 for the 503A list on July 23, 2026, for ulcerative colitis. An advisory committee gives advice; it does not approve a drug. Regulatory status can change, so check the date on the FDA page itself. Our guide to whether peptides are legal explains the categories in more detail.
BPC-157 in sport
If you compete in a tested sport, BPC-157 is banned at all times. The World Anti-Doping Agency’s 2026 Prohibited List names it in class S0, Non-Approved Substances, in and out of competition.
A doctor’s prescription does not protect you. In 2023 a UFC athlete who had been prescribed BPC-157 by a doctor still received a four-month sanction, reduced because she reported it herself. Our guide to peptides and the WADA list covers other cases.
Checks if you are considering or already using it
- Know what the label cannot tell you. A “research use only” vial has not been made or tested as a medicine. Our guide to research use only peptides explains what that label means.
- Do not treat a certificate of analysis as a safety test. Purity on one sample says nothing about sterility.
- Tell your doctor or pharmacist what you have taken, including the product name, so it can be considered if you develop symptoms or need surgery.
- Watch the injection site. Spreading redness, warmth, swelling, pus or fever needs same-day medical care.
If you have a reaction after using BPC-157, you can report it to FDA MedWatch, the agency’s safety reporting program, which takes reports directly from patients and consumers as well as health professionals.
Sources
- Vasireddi N, et al. Emerging Use of BPC-157 in Orthopaedic Sports Medicine: A Systematic Review. HSS Journal, 2025.
- McGuire FP, et al. Regeneration or Risk? A Narrative Review of BPC-157 for Musculoskeletal Healing. Current Reviews in Musculoskeletal Medicine, 2025.
- Lee E, Padgett B. Intra-Articular Injection of BPC 157 for Multiple Types of Knee Pain. Alternative Therapies in Health and Medicine, 2021.
- Lee E, Walker C, Ayadi B. Effect of BPC-157 on Symptoms in Patients with Interstitial Cystitis: A Pilot Study. Alternative Therapies in Health and Medicine, 2024.
- Lee E, Burgess K. Safety of Intravenous Infusion of BPC157 in Humans: A Pilot Study. Alternative Therapies in Health and Medicine, 2025.
- Chang CH, et al. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. Journal of Applied Physiology, 2011.
- Hsieh MJ, et al. Therapeutic potential of pro-angiogenic BPC157 is associated with VEGFR2 activation and up-regulation. Journal of Molecular Medicine, 2017.
- ClinicalTrials.gov. NCT02637284: PCO-02 Safety and Pharmacokinetics Trial.
- US Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks.
- US Food and Drug Administration. Bulk Drug Substances Used in Compounding.
- US Food and Drug Administration. Drugs@FDA: FDA-Approved Drugs.
- US Food and Drug Administration. MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
- Federal Register. Pharmacy Compounding Advisory Committee; Notice of Meeting (FR Doc 2026-07361), April 16, 2026.
- Electronic Code of Federal Regulations. 21 CFR 216.23, Bulk drug substances that can be used to compound drug products under section 503A.
- World Anti-Doping Agency. The 2026 Prohibited List.
- US Anti-Doping Agency. BPC-157: What Athletes Should Know About the Prohibited Experimental Peptide.
- US Anti-Doping Agency. Cortney Casey Accepts Sanction for Violation of UFC Anti-Doping Policy.