A research-based guide to the peptides most studied for muscle growth, GH axis optimization, and training recovery — covering mechanisms, how strong the evidence is for each, safety unknowns and WADA status. We do not publish dosing, stack or cycle protocols.
WADA Prohibited — All Compounds Listed
All peptides covered in this guide are prohibited by the World Anti-Doping Agency (WADA) under S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics). Competitive athletes subject to anti-doping testing should not use these compounds. This guide is for research and educational purposes only.
IGF-1 LR3 directly activates the PI3K/Akt/mTOR signaling cascade — the master regulator of muscle protein synthesis. This is the same pathway resistance training activates; whether IGF-1 LR3 adds anything to training in people has not been tested.
CJC-1295 acts on the GHRH receptor and Ipamorelin on the ghrelin receptor; each raises GH in early studies, and GHRH and GHRP pairs in general give larger responses together. No trial has tested the pair for a body-composition outcome.
IGF-1 LR3 activates muscle satellite cells (myogenic stem cells), in cell and animal studies; whether this happens in people at any amount has not been shown. This mechanism is distinct from androgen receptor-mediated anabolism.
BPC-157 upregulates VEGF and activates the FAK-paxillin pathway, accelerating tendon and ligament repair. TB-500 regulates actin polymerization and reduces systemic inflammation. These are rodent findings; they have not been tested in people who train.
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| Compound | Role | Mechanism | Established dose | Human data | Evidence |
|---|---|---|---|---|---|
| IGF-1 LR3Anabolic | Long R3 IGF-1 analogue. Activates mTOR signalling in cell and animal studies. No human muscle trials. | IGF-1R → PI3K/Akt/mTOR → protein synthesis + satellite cell activation | None | None for LR3 | Cell + animal |
| CJC-1295GH Axis | GHRH analogue. Raises GH and IGF-1 in early human studies. The DAC version has a half-life of about a week. | GHRH-R agonist → ↑ GH pulse amplitude → ↑ IGF-1 | None | Early PK studies; development stopped | Early human |
| IpamorelinGH Secretagogue | Selective GHSR agonist. Triggers GH release with little cortisol or prolactin rise in early studies. | GHSR-1a agonist → selective GH pulse → ↑ IGF-1 | None | Phase 2 IV trial (post-surgical bowel) missed its goal | Early human |
| BPC-157Recovery | Pentadecapeptide. Improved tendon, ligament and muscle repair in rodent injury models. | VEGF upregulation + FAK-paxillin pathway → angiogenesis + tissue repair | None | Three small uncontrolled reports | Animal (extensive) |
| TB-500Recovery | Thymosin Beta-4 fragment. Actin-binding fragment; cell migration and wound repair in animal models. | Actin regulation + MMP-2 upregulation → cell migration + anti-inflammation | None | None for the fragment | Animal |
| GHK-CuSkin & Collagen | Copper-binding tripeptide. Collagen and skin-remodelling effects, mainly in topical and cell studies. | TGF-β activation + MMP modulation → collagen synthesis + skin remodeling | None (injectable) | Topical cosmetic studies only | Topical + animal |
Bulking, recovery and contest-prep "stacks" combine compounds that have each been studied separately, mostly in cells or rodents. No trial has tested any of these combinations for muscle, fat loss or recovery, and no dose, route, timing or cycle length has been established for any of them in people. The protocols shared online come from forums and vendor marketing. Compound Review does not publish dosing, stack or cycling protocols. Every compound here is sold for laboratory research only, is not for human or animal consumption, and is prohibited in tested sport.
mTOR signalling and satellite-cell activation in cell and animal studies
GHRH analogue: raises GH and IGF-1 in early human studies
Selective GH release with little cortisol rise in early studies
Long R3 IGF-1 analogue. Activates mTOR signalling in cell and animal studies. No human muscle trials.
GHRH analogue. Raises GH and IGF-1 in early human studies. The DAC version has a half-life of about a week.
Selective GHSR agonist. Triggers GH release with little cortisol or prolactin rise in early studies.
Pentadecapeptide. Improved tendon, ligament and muscle repair in rodent injury models.
Thymosin Beta-4 fragment. Actin-binding fragment; cell migration and wound repair in animal models.
Copper-binding tripeptide. Collagen and skin-remodelling effects, mainly in topical and cell studies.
The ones people ask about are IGF-1 LR3 (a growth-factor analogue used mainly in cell culture), CJC-1295 and Ipamorelin (which raise growth hormone), BPC-157 and TB-500 (studied in rodents for tissue repair) and GHK-Cu (a copper peptide studied mostly in skin). None has a controlled trial showing muscle gain or better recovery in healthy people, and none is approved for those uses.
IGF-1 LR3 binds the IGF-1 receptor and activates the PI3K/Akt/mTOR pathway that drives protein synthesis; it is engineered to escape binding proteins, so it lasts far longer than native IGF-1. That is established in cell and animal work. There are no human trials of IGF-1 LR3 for muscle, and low blood sugar is its known risk.
Each raises growth hormone in early studies, through different receptors, and GHRH and GHRP pairs in general give larger GH responses together than apart. No trial has tested this pair for muscle, fat loss or recovery, and raising GH has not been shown to improve strength in healthy adults. We do not publish stack protocols.
No. Steroids act directly on androgen receptors and have a large body of evidence for muscle gain. The research peptides here act on growth-hormone, IGF-1 or repair pathways, and none has shown comparable effects on muscle in human trials.
Yes. IGF-1 LR3, CJC-1295, Ipamorelin, BPC-157 and TB-500 are all prohibited by WADA, and WADA-accredited laboratories test for them in urine and blood. Competitors in any tested federation should not use them.
No. The bulking and cutting 'stacks' and cycles shared online, with their doses and timings, come from forums and vendor marketing rather than studies. Compound Review does not publish dosing, stack or cycling protocols. These compounds are sold for laboratory research only and are not for human or animal consumption.
There is no research basis for cycle lengths for any of these compounds, and we do not publish them.
BPC-157 and TB-500 improved tendon, ligament and muscle repair in rodent injury models. Whether they do anything for recovery from training in people has not been tested in a controlled trial. Pre-mixed blends add a further question: whether the certificate covers the blend or only the separate raw materials.
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