K4 Elite
K4 Elite
BPC-157 (pentadecapeptide GEPPPGKPADDAGLV) has been studied almost entirely in rodent models, most often in rats given 10 µg/kg or 10 ng/kg intraperitoneally, intragastrically or in drinking water, across tendon, ligament, muscle, gastrointestinal and NSAID-toxicity models. No completed, published randomised controlled trial in humans exists; the human literature consists of a retrospective chart review of 17 patients given intra-articular injections (Lee & Padgett 2021) and a two-participant intravenous pilot (Lee & Burgess 2025), both in the same non-indexed journal. A Phase 1 oral study (NCT02637284) was registered in 2015 but no results have been posted. In September 2023 the U.S. FDA placed BPC-157 in Category 2 of its 503A bulk-substance interim policy, citing immunogenicity and impurity concerns and 'no, or only limited, safety-related information'; the nomination has since been withdrawn.
Each row records what a published study did: who it enrolled, the regimen it administered to those subjects, and what it reported. These are historical study descriptions, not protocols to follow.
| Study | Population | Regimen as reported | Primary findings |
|---|---|---|---|
| Staresinic et al., J Orthop Res 2003 (rat Achilles tendon transection, preclinical) | Rats with surgical transection of the right Achilles tendon 5 mm proximal to the calcaneal insertion | Rats were administered BPC 157 dissolved in saline at 10 µg/kg, 10 ng/kg or 10 pg/kg, or saline 5 mL/kg, intraperitoneally once daily, starting 30 min after surgery with the last dose 24 h before assessment on day 1, 4, 7, 10 or 14. | BPC 157-treated rats showed higher load to failure, Young's modulus and Achilles functional index values than saline controls, with smaller tendon defects on macroscopic and microscopic assessment. |
| Krivic et al., Inflamm Res 2008 (rat Achilles tendon-to-bone transection, preclinical) | 72 male Wistar albino rats with surgical transection of the Achilles tendon-to-bone junction | Rats were given BPC 157 10 µg/kg, methylprednisolone 5 mg/kg or saline 5 mL/kg intraperitoneally once daily, first dose 30 min after surgery and last dose 24 h before analysis on days 1-4. | BPC 157 increased Achilles functional index values at all time points and reduced myeloperoxidase activity and inflammatory cell influx while increasing vascular index; methylprednisolone reduced inflammation but also reduced new vessel formation and did not change functional recovery. |
| Chang et al., J Appl Physiol 2011 (rat tendon explants and cultured tendon fibroblasts, ex vivo / in vitro) | Achilles tendon explants and primary tendon fibroblasts derived from rats | Tendon explants and cultured rat tendon fibroblasts were incubated with or without BPC 157 at graded concentrations; outgrowth, MTT proliferation, survival under H2O2 stress, transwell migration, spreading and FAK/paxillin phosphorylation were measured. | BPC 157 accelerated explant outgrowth, increased fibroblast survival under oxidative stress and dose-dependently increased migration and FAK/paxillin phosphorylation, without directly changing proliferation. |
| Ilic et al., Life Sci 2011 (rat diclofenac-toxicity model, preclinical) | Rats given diclofenac 12.5 mg/kg intraperitoneally once daily for 3 days to induce gastrointestinal, liver and brain lesions | Rats received BPC 157 10 µg/kg or 10 ng/kg intraperitoneally immediately after each diclofenac dose, or BPC 157 in drinking water at 0.16 µg/mL or 0.16 ng/mL. | Diclofenac-induced gastric, intestinal, hepatic and encephalopathy lesions were reported to be reduced in BPC 157-treated rats by both routes. |
| Biçer et al., Jt Dis Relat Surg 2026 (rat Achilles tendon repair; BPC-157 alone, TB-500 alone, and combined; preclinical) | 32 male Sprague-Dawley rats (12 weeks old, ~330 g) after standardised Achilles tendon transection and repair, 8 per group | Rats were administered BPC-157 10 µg/kg/day, TB-500 60 µg/kg/day, both, or vehicle intraperitoneally for four weeks after surgery; tendons were harvested at four weeks for biomechanical and histological testing. | Maximum load to failure was numerically higher in both peptide groups but reached significance only for TB-500; BPC-157 alone showed numerically lower histology scores without significance, and the combination did not add benefit over either agent alone. |
| Lee & Padgett, Altern Ther Health Med 2021 (retrospective chart review, human) | 17 patients with knee pain of mixed aetiology treated at a single private clinic in Orlando, Florida (16 reached for telephone follow-up) | Patients had received an intra-articular injection of BPC 157, alone or combined with thymosin beta-4, 6 to 12 months before a telephone survey; no validated outcome instruments were used. | The report is an uncontrolled retrospective survey of patient-rated pain relief; no objective outcome or control group was included, and the authors state the peptides had not previously been studied for knee pain. |
| Lee & Burgess, Altern Ther Health Med 2025 (open-label intravenous pilot, human, n=2) | Two adults (a 58-year-old man and a 68-year-old woman) at a private clinic in Florida, both of whom had previously received intravenous BPC-157 | Participants received 10 mg BPC-157 in 250 mL normal saline infused over one hour on day 1 and 20 mg in 250 mL over one hour on day 2, with fasting blood work and vital signs before and after each infusion. | The authors reported no measurable change in cardiac, hepatic, renal, thyroid or glucose biomarkers and no side effects reported by the two participants. |
| PCO-02 Phase 1 safety and pharmacokinetics trial (PharmaCotherapia d.o.o.; registered, status unknown, no results posted) Registry: NCT02637284
|
Healthy volunteers (planned n=42) | The registration describes single oral doses of 1, 3 or 6 tablets of PCO-02 each containing 1 mg of 'Bepecin' (BPC 157) or matching placebo in Phase 1a, followed by a multiple-dose Phase 1b. | No results have been posted to ClinicalTrials.gov and the record status is listed as unknown; no peer-reviewed publication of this trial was located. |
Effects recorded in the cited reports. Frequencies are those the source reported, in the population that source studied.
| Effect | Frequency / context | Source |
|---|---|---|
| No adverse effects reported in the three small human pilot reports (animal/pilot-level evidence only) | A 2025 narrative review identified only three pilot human studies (intra-articular knee pain, interstitial cystitis, intravenous safety/pharmacokinetics) and states that no adverse effects were reported but that rigorous, large-scale trials are lacking; the reviewers concluded BPC-157 should be considered investigational. | Regeneration or Risk? A Narrative Review of BPC-157 for Musculoskeletal Healing (Curr Rev Musculoskelet Med 2025) ↗ |
| Immunogenicity and peptide-impurity risk (regulatory assessment, not an observed clinical event) | FDA's Category 2 safety statement: compounded BPC-157 'may pose risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and active pharmaceutical ingredient (API) characterization'; FDA 'lacks sufficient information to know whether the drug would cause harm when administered to humans'. | FDA — Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks ↗ |
| Animal toxicity: no lethal dose identified (author-group claim) | The originating research group states in a 2025 review that an LD1 was not achieved in animal toxicology; this is the group's own summary and independent toxicology data were not located. | Stable Gastric Pentadecapeptide BPC 157 as a Therapy and Safety Key: A Special Beneficial Pleiotropic Effect Controlling and Modulating Angiogenesis and the NO-System (Pharmaceuticals 2025) ↗ |
Interactions documented in trial reports, prescribing information or pharmacology references.
| Agent | Type | Note | Source |
|---|---|---|---|
| NSAIDs (diclofenac; rat model) | pharmacodynamic (preclinical) | In rats given diclofenac 12.5 mg/kg/day for 3 days, co-administered BPC 157 (10 µg/kg or 10 ng/kg i.p., or 0.16 µg/mL or 0.16 ng/mL in drinking water) was reported to reduce diclofenac-induced gastrointestinal, liver and brain lesions. No human interaction data exist. | Pentadecapeptide BPC 157 and its effects on a NSAID toxicity model: diclofenac-induced gastrointestinal, liver, and encephalopathy lesions (Life Sci 2011) ↗ |
| Nitric-oxide pathway agents: L-NAME (NOS inhibitor) and L-arginine (NOS substrate) (rat models) | pharmacodynamic (preclinical) | In 24-hour short-bowel rats, BPC 157 (10 µg/kg or 10 ng/kg i.p.) was tested alone and combined with L-NAME 5 mg/kg and L-arginine 100 mg/kg; the authors report BPC 157 counteracted L-NAME-aggravated outcomes, and the group describes a general BPC 157–NO-system interaction across many rat models. | Effects of Diclofenac, L-NAME, L-Arginine, and Pentadecapeptide BPC 157 on Gastrointestinal, Liver, and Brain Lesions, Failed Anastomosis, and Intestinal Adaptation Deterioration in 24 Hour-Short-Bowel Rats (PLoS One 2016) ↗ |
| Antiplatelet agents: aspirin, clopidogrel, cilostazol (rat model) | pharmacodynamic (preclinical) | Rats received aspirin, clopidogrel or cilostazol 10 mg/kg intragastrically once daily for 3 days followed immediately by BPC 157 10 µg/kg or saline; platelet aggregometry and thromboelastometry were assessed 2 h after the last dose. The authors report that BPC 157 counteracted the inhibitory effects of these antiplatelet agents on aggregation induced by arachidonic acid, ADP and collagen, with no effect on thromboelastometry clotting parameters. This is a potential pharmacodynamic opposition to antiplatelet therapy observed in rats only; no human data exist. | Intragastric Application of Aspirin, Clopidogrel, Cilostazol, and BPC 157 in Rats: Platelet Aggregation and Blood Clot (Oxid Med Cell Longev 2019) ↗ |
Exclusions and label contraindications recorded in the cited sources.