Type "wolverine stack" into any forum and the answer comes back with a confidence the literature does not support: two peptides, one for the gut, one for wounds, combined into a regimen for tendons, ligaments and comebacks from injury. This page counts what actually exists in humans for each compound, explains what TB-500 is (it is not what the name suggests), sets out the banned-status facts, and separates the question of healing from the question of muscle. It is research journalism about research compounds; it contains no usage guidance, per our editorial standards.
What the two compounds are
BPC-157 (Body Protection Compound-157) is a synthetic 15-amino-acid peptide derived from a protein found in human gastric juice. Its literature is large and, as a 2025 commentary in Pharmaceuticals points out, unusually concentrated: "over 80% of BPC-157 studies originate from a single research group", and the only Phase I trial the commentary could find was cancelled. The authors add that "without independent, well-designed multi-dose studies, long-term safety evaluations, and randomized clinical trials, it will remain difficult to convince the broader medical community that this so-called 'wonderful' compound meets the criteria of a legitimate therapeutic agent" (Pharmaceuticals 2025, PMC12567171).
TB-500 is sold as if it were thymosin beta-4, a 43-amino-acid protein present in most human cells that binds actin and is involved in cell migration and wound repair. It is not. TB-500 is "Ac-LKKTETQ, derived from the active site of thymosin β4", a synthetic, acetylated seven-residue fragment. The 2024 paper that developed a method to measure it in urine states plainly: "The biological effects of TB-500, however, have not been documented" (Rahaman et al., Journal of Chromatography B 2024). The fragment's marketing borrows the protein's biology.
The human evidence, counted
We searched PubMed on 2026-09-05. The counts are the finding.
| Question | Search | Result |
|---|---|---|
| Clinical trials of BPC-157 in humans | BPC-157 with the clinical-trial or RCT publication-type filter | 0 |
| Human studies of BPC-157 of any design | BPC-157 AND humans | 53 records, nearly all reviews, commentaries and analytical-chemistry papers; one retrospective case series |
| Human trials of TB-500 | TB-500 AND humans | 16 records, none a trial of TB-500; reviews and doping-detection papers |
| Clinical trials of thymosin beta-4 (the full protein) | thymosin beta-4 with the clinical-trial filter | 9, in heart disease, dry eye and healthy volunteers |
| Human studies of the combination | BPC-157 AND TB-500 | 7 records, all reviews or commentaries |
The one human BPC-157 study everyone cites is a retrospective series of intra-articular knee injections. The 2025 HSS Journal systematic review, which found "35 preclinical studies" and "1 clinical study" among 36 BPC-157 musculoskeletal papers, describes it: "a retrospective study of musculoskeletal pain following intraarticular injection of BPC-157 for unspecified chronic knee pain, 7 of 12 patients reported relief for >6 months." The reviewers' conclusion: "The lack of clinical outcome and safety data prevents us from proposing evidence-based practice use guidelines", and "clinicians and athletes should exercise caution when considering the use of BPC-157" (HSS Journal 2025, PMC12313605). A 2026 scoping review in the American Journal of Sports Medicine that covered BPC-157, TB-500, CJC-1295, MK-677, ipamorelin and GHK-Cu found that "67% of identified publications utilized preclinical animal models" and that "human clinical studies were limited to a handful of investigations, most lacking robust controls or rigorous study designs" (Tewari et al., AJSM 2026). A second 2026 AJSM paper, a primer for orthopaedic surgeons, reached the same place: BPC-157 "demonstrated potential benefits in tendon and muscle repair, but these findings are largely unvalidated in human trials" (Mayfield et al., AJSM 2026).
For thymosin beta-4, the human trials are real but beside the point of the stack. A 2010 phase 1 study gave healthy volunteers intravenous synthetic Tβ4 at 42 to 1,260 mg, single and then daily for 14 days, with infrequent, mild-to-moderate adverse events and no dose-limiting toxicity, with cardiac ischemia as the intended indication (Ruff et al., Ann N Y Acad Sci 2010). A 2022 phase 1 study of recombinant Tβ4 in 54 healthy Chinese volunteers found it "well tolerated and safe", again aimed at myocardial infarction (Wang et al., J Cell Mol Med 2022). A phase 2 trial of 0.1% Tβ4 eye drops in nine patients with severe dry eye reported a 35.1% reduction in discomfort and a 59.1% reduction in corneal staining versus vehicle (Sosne et al., Cornea 2015). None of these is a tendon, muscle or performance study, and none used TB-500.
Where the stack claims come from
Rats. The animal literature for both compounds reports faster tendon-to-bone healing, wound closure and angiogenesis, and the 2026 Sports Medicine review by Mendias and Awan summarises the position fairly: "Many unapproved peptides demonstrate favorable tissue repair and metabolic outcomes in animal models, but rigorous human safety data are scarce, and there is potential for serious harm to patients." The same paper describes the market: "a parallel 'gray market' of unapproved compounds has emerged, operating largely outside of regulatory oversight" (Mendias and Awan, Sports Medicine 2026). The name itself is a Reddit coinage; it does not appear in a journal.
Healing is not muscle
The stack is marketed to lifters, so it is worth being exact about what the animal studies measure: tendon healing, wound closure, vessel growth, gut-lining repair. Not muscle cross-sectional area, not strength, not work capacity. On our evidence ledger both compounds score 1 out of 5 for muscle growth, the score for no human muscle data at all. Whether either helps an injury heal in a human is a separate question, and the answer above is that nobody has tested it in a controlled trial. A compound can be useless for muscle and useful for healing, or neither; the point is that the evidence does not currently let anyone say which.
Banned status and detection
On the 2026 WADA Prohibited List, effective 2026-01-01, BPC-157 is named among the examples under S0, non-approved substances, and "Thymosin-β4 and its derivatives e.g. TB-500" appear under S2.3, growth factors and growth factor modulators. Both classes are prohibited at all times, in and out of competition. The NCAA's 2026-27 banned-drug classes name "BPC-157" and "TB-500" under peptide hormones, growth factors, related substances and mimetics. For US Service Members, BPC-157 is on the DoD Prohibited Dietary Supplement Ingredients List under DoDI 6130.06, and Operation Supplement Safety says research-chemical labels do not change that. Anti-doping laboratories screen for both by mass spectrometry; a 2026 method detects them, with 52 other agents, in dried blood spots. Our drug-testing page covers what each test looks for.
Regulatory status
Neither compound is approved as a drug anywhere. Both are sold in the United States by research-chemical vendors under labels such as "research use only" and "not for human consumption". FDA's warning letters to peptide sellers state that such labels do not control intended use when the seller's site makes therapeutic claims; the letters are tracked, with FDA's wording, on Peptifact. FDA's compounding bulk-substances page, updated 2026-04-22, records BPC-157 and TB-500 among substances it has reviewed for immunogenicity and peptide-impurity concerns with limited human safety data.
What is not known
Whether BPC-157 or TB-500 does anything for a human tendon, ligament or muscle; whether the combination adds anything to either alone; what the safe dose range is in humans, since no dose-ranging trial exists; and what long-term use does, since no one has followed it. What is known is the animal literature, its concentration in one laboratory, one uncontrolled knee series, and a set of rules that treat both compounds as prohibited for tested athletes and Service Members.
Sources and dates
PubMed searched and abstracts opened 2026-09-05: HSS Journal 2025 systematic review (PMC12313605); Pharmaceuticals 2025 commentary (PMC12567171); Tewari et al., AJSM 2026 (PMID 42578445); Mayfield et al., AJSM 2026 (PMID 41476424); Mendias and Awan, Sports Medicine 2026 (PMID 41966639); Rahaman et al., J Chromatogr B 2024 (PMID 38382158); Ruff et al. 2010 (PMID 20536472); Wang et al. 2022 (PMID 34346165); Sosne et al. 2015 (PMID 25826322). Also opened: the 2026 WADA Prohibited List, NCAA 2026-27 banned classes, OPSS on BPC-157 (2025-04-29), FDA's category-2 bulk-substances page (2026-04-22). Corrections go to the contact page.