Quick answer: BPC-157 side effects in people are largely unknown, because only about 30 people have taken part in published human studies, and none of those studies reported a treatment-related adverse event.[2] FDA’s 2026 review adds three adverse event reports (injection-site swelling, shortness of breath and skin darkening) and animal data with possible clotting, liver and kidney signals.[1] No study has followed people long term.
BPC-157 is an unapproved peptide sold for tendon, muscle and gut healing. This guide sorts what has been seen in people, what showed up in animals, and the questions people search most, about the kidneys, liver, heart and blood pressure. For background, see our BPC-157 profile and the healing peptides hub.
Why so little is known
Three small published studies make up the human evidence: a knee pain chart review (16 people), a bladder pain pilot (12 women) and an IV safety pilot (2 adults).[2]
- None had a placebo or comparison group.[2]
- A 2026 systematic review judged all three to be of poor quality and rated the certainty of evidence as very low.[2]
- Safety monitoring in most studies was unclear, the studies were short, and the doses were exploratory.[1]
The reviewers concluded BPC-157 should not be used in people outside approved, regulated clinical trials.[2] A 2025 review reached a similar view: no adverse effects were reported, but large, rigorous trials are lacking.[10] An absence of reported problems in 30 people is not the same as proof of safety. For the full trial list, see BPC-157 clinical trials.
Side effects reported in people
| Source | What was reported |
|---|---|
| Healthy volunteers, enema studies (Croatia) | Headache and gas (flatulence) were the most common[1] |
| Bladder pain pilot, 12 women | No adverse events reported[4] |
| IV pilot, 2 adults, 10 mg then 20 mg | No side effects reported; no change in tested blood markers[3] |
| Knee pain chart review, 16 people | Follow-up was a phone survey on pain only[5] |
| FDA adverse event reports | Injection-site redness and swelling for 9 days; shortness of breath leading to an ER visit; diffuse skin darkening and darker gums when used with TB-500[1] |
FDA noted that it could not tell whether BPC-157 caused these reported events. One person was also injecting another peptide, and voluntary reports often lack detail.[1] The skin and gum darkening came back when that person restarted the products, which is called a positive rechallenge.[1]
BPC-157 and the kidneys
- In people: in the IV pilot, blood tests of kidney function did not change after 10 mg and 20 mg infusions.[3] That was 2 people over 3 days.
- In dogs: FDA flagged a change in blood creatinine in female dogs given 2 mg/kg a day for 28 days.[1] The study authors described it as a decrease that did not occur at lower doses and returned to normal 2 weeks after stopping.[6]
- In rats: the original Croatian research group reports that BPC-157 counteracted kidney damage from the antibiotic gentamicin.[9] That is an animal treatment study, not a human safety finding.
- Clearance: in rats, BPC-157 was broken down quickly into smaller fragments and cleared mainly in urine and stool.[7]
Nobody has studied BPC-157 in people with kidney disease.
BPC-157 and the liver
FDA’s review of 28-day injection studies found “potentially liver-associated signals” that it considered possibly clinically relevant:[1]
- higher triglycerides during treatment in female rats and female dogs
- higher ALT (a liver enzyme), triglycerides and glucose, and a heavier liver relative to body weight, 14 days after treatment ended in female rats
The authors of that toxicology study, from China, read the same work as showing BPC-157 was well tolerated, with no serious toxicity in four animal species.[6] The two people in the IV pilot had no change in liver tests.[3] FDA noted that no longer-term animal studies exist to show whether these signals persist or new ones appear.[1]
BPC-157, blood pressure and the heart
- Blood pressure: no published study reports blood pressure changes in people using BPC-157. In artery segments removed during heart bypass surgery in Türkiye, BPC-157 relaxed the vessel in the lab through nitric oxide. The authors called this early evidence whose clinical relevance needs more study.[8]
- Heart tests: the IV pilot found no change in tested heart blood markers.[3]
- Breathing: one FDA report described shortness of breath leading to an emergency room visit; the cause was unclear.[1]
- Clotting: FDA saw changes in aPTT, a clotting time test, in rats at 1 mg/kg a day and in dogs at 0.5 mg/kg a day.[1] Whether this matters in people, for example those on blood thinners or facing surgery, is unknown.
A 2026 review of unregulated injectable “biohacking” drugs lists cardiovascular stress, abnormal blood vessel growth and cancer promotion among the potential risks of this group of products, including BPC-157.[11]
Cancer and immune reactions
Because BPC-157 helps form new blood vessels, Cleveland Clinic notes researchers worry it could also promote cancer growth.[12] No study has tested this directly, and none shows that BPC-157 causes cancer.
FDA also says BPC-157 may pose a significant risk of immune reactions when injected or sprayed in the nose. Clumping (aggregation) and impurities from manufacturing could make that worse.[1] FDA had placed BPC-157 on its list of compounding substances that may present significant safety risks. The nomination has since been withdrawn, but FDA’s April 2026 page still says the agency lacks enough information to know whether BPC-157 causes harm in people.[13]
Product quality risks
Cleveland Clinic separates the safety of BPC-157 itself from the safety of where it comes from. Products may not contain BPC-157, may contain other ingredients or allergens, or may be expired or contaminated with toxins or heavy metals such as lead or arsenic.[12] Self-injecting also brings infection risk from shared or reused needles.[12] See our guides to counterfeit peptides and peptide injection-site reactions.
Pregnancy and other groups
In pregnant rats, daily injections up to 4 mg/kg did not cause birth defects or affect fetal survival, but there are no studies covering a full reproductive cycle or breastfeeding, and no human data.[1] People who are pregnant or breastfeeding, have a history of cancer, take blood thinners or have liver or kidney disease have no safety data to go on. Competitive athletes should check anti-doping rules; see is BPC-157 legal.
What about dose?
Higher doses have not been shown to be safer or more effective. The human studies used a single 10 mg bladder injection and IV doses of 10 mg then 20 mg; no dose is approved.[4][3] BPC-157 lasts under 30 minutes in the blood of rats and dogs.[7] For what was tested, see our BPC-157 dosage guide, and for how the route changes exposure, oral vs injectable BPC-157. Combining it with other peptides adds more unknowns; see the BPC-157 and TB-500 stack.
Questions to ask a clinician
- Is there an approved treatment with known side effects for my injury or condition?
- Which blood tests (kidney, liver, clotting) would you check if I have already used BPC-157?
- Could BPC-157 interact with my medicines, such as blood thinners?
- Are there any registered clinical trials I could join instead?
If you develop shortness of breath, a spreading rash, swelling of the face or throat, or a hot, painful injection site, seek medical care promptly.
