The best peptides for athletes are the ones that are both legal and backed by human data, and that is a short list: collagen peptides or vitamin C-enriched gelatin taken before loading exercise, which doubled a blood marker of collagen production in one small trial and sped up Achilles tendinopathy recovery in another.[5][6] Growth hormone peptides, IGF-1, BPC-157 and TB-500 are prohibited at all times under WADA rules and lack proof that they improve performance or healing in people.[1][11]
This guide covers the prohibited list, testing, collagen for tendons and recovery claims. For more, visit our muscle and metabolism peptides hub.
Evidence-graded table
| Peptide or drug | Evidence level | What was shown | FDA / WADA status | Our profile |
|---|---|---|---|---|
| Collagen peptides or gelatin with loading | Small human studies | Doubled a collagen-synthesis marker; faster Achilles improvement; no added tendon growth in a 15-week RCT[5][6][8] | Food; not prohibited | None |
| Insulin (for type 1 diabetes) | FDA-approved (for diabetes, not performance) | Standard diabetes treatment | Approved; prohibited in sport, TUE possible[2] | None |
| Growth hormone | Human RCTs | +2.1 kg lean mass, no strength or endurance gain[10] | Approved for deficiency; prohibited[1] | HGH |
| CJC-1295, ipamorelin, MK-677, GHRPs | Small human studies (hormone levels only) | Raise GH; no performance trials | Not approved; prohibited[1] | CJC-1295, Ipamorelin, MK-677 |
| IGF-1 LR3, PEG-MGF | Animal or lab only | No human studies | Not approved; prohibited[1] | IGF-1 LR3, PEG-MGF |
| BPC-157 | Animal or lab only | 35 of 36 studies preclinical; 7 of 12 knee-pain patients reported relief in one uncontrolled series[11] | Not approved; prohibited (S0)[1] | BPC-157 |
| TB-500 | Animal or lab only | Repair in animal models[12] | Not approved; prohibited[1] | TB-500 |
Results come from different groups of people and are not head-to-head comparisons.
The WADA prohibited list: where peptides sit
WADA’s 2026 Prohibited List puts most performance peptides in section S2 (peptide hormones, growth factors, related substances and mimetics), banned in and out of competition.[1] That includes:
- GH and its fragments, including AOD-9604
- GH-releasing factors: CJC-1295, sermorelin, tesamorelin, ipamorelin, MK-677, GHRP-2, GHRP-6 and hexarelin
- Growth factors: IGF-1 and its analogues, mechano growth factors and thymosin beta-4 derivatives such as TB-500
- Testosterone-stimulating peptides in males: hCG, LH, gonadorelin and kisspeptin
BPC-157 is named under S0, the catch-all for substances with no human approval anywhere.[1] USADA says that on the 2027 List, effective January 1, 2027, “peptides” in general are named under S0. Insulin is prohibited under S4. Semaglutide and tirzepatide are not prohibited, but both are in the 2027 monitoring program, which tracks use without sanctions.[2]
Approval does not protect you. Tesamorelin and growth hormone are approved medicines, yet both are banned for athletes.[1] Our full guide to the WADA prohibited list quotes each section.
Testing and strict liability
Under the World Anti-Doping Code, athletes are strictly liable for what is in their bodies.[2] Anti-doping labs have built tests for newer peptides: a 2017 study of confiscated vials developed a urine method that detects BPC-157 at 0.1 ng/mL.[13]
Supplements carry their own risk. In an international study of 634 non-hormonal supplements bought in 13 countries, 14.8% contained anabolic steroids not listed on the label.[14] USADA also warns that not every prohibited peptide appears in its lookup tool, and that peptides may be sold under slang names.[2]
If you have a real medical need for a prohibited medicine, a therapeutic use exemption (TUE) is the route. USADA walks athletes through the process from diagnosis to decision, and it covers emergency treatment.[3]
Collagen for tendons: helpful with loading, not alone
Tendons respond to mechanical load. The question is whether collagen peptides, which supply the amino acids glycine, proline and hydroxyproline, add anything.
- Timing study: in 8 healthy men, 15 g of vitamin C-enriched gelatin taken an hour before 6 minutes of rope skipping doubled a blood marker of new collagen formation compared with placebo.[5]
- Achilles tendinopathy: in a 20-patient crossover pilot, specific collagen peptides with twice-daily calf strengthening improved a standard Achilles score faster than placebo with the same exercises.[6]
- Joint pain: in a 24-week trial of 147 college athletes (97 analyzed), 10 g of collagen hydrolysate modestly reduced activity-related joint pain versus placebo.[7]
- Healthy tendons: in a 15-week trial of 39 young men doing leg training, 15 g of collagen daily added no tendon size or stiffness gains over placebo.[8] Another trial found 30 g a day did not raise connective-tissue protein synthesis.[9]
The IOC consensus statement notes that only a few supplements, such as caffeine, creatine, buffering agents and nitrate, have good evidence of direct performance benefits.[4] Collagen is a reasonable, legal add-on for tendon rehab, not a performance drug. Learn more in peptide hormones and exercise.
Recovery claims vs evidence
Growth hormone peptides. A review of 27 study groups of fit adults found growth hormone increased lean mass by about 2.1 kg but did not improve strength or exercise capacity, and may have worsened it.[10] Secretagogues that raise GH have even less data.
BPC-157. A 2025 systematic review found 36 studies, 35 in animals. The one human study was a retrospective series in which 7 of 12 people reported knee-pain relief after injection, with no control group and no clinical safety data.[11]
TB-500 and others. A 2026 Sports Medicine review concluded that these peptides show tissue repair effects in animal models, but rigorous human safety data are scarce and there is potential for serious harm. The authors also highlight the placebo effect, amplified by social media.[12]
Questions to discuss with your team physician
- Is my injury best managed with a progressive loading program, and would collagen before sessions be reasonable?
- Is any medicine I take on the current prohibited list, and do I need a TUE?
- Are my supplements third-party tested for banned substances?
See also peptides and exercise and our evidence review of best peptides for muscle growth.
The bottom line
For athletes, the best-supported peptide is also the most boring: collagen or gelatin timed before tendon loading, as part of rehab. Nearly every injectable peptide marketed for recovery or performance is banned and untested in people.
