“CJC-1295 builds muscle in healthy adults.”
No study has tested whether CJC-1295 builds muscle in healthy adults; trials measured only hormone levels.
CJC-1295 raises growth hormone, but nobody has shown that it builds muscle, and it carries real safety warnings. It is not worth the injections or the risk for muscle gain.
Skip CJC-1295 for muscle and put that effort into a steady strength-training plan.
Safety note: FDA has flagged serious reactions with CJC-1295, including a fast heart rate and a sudden widening of blood vessels. A 2006 trial in people with HIV was stopped after a participant died; a link to the drug was not established. CJC-1295 is not an approved medicine, and it is banned in sport at all times.
Talk to a healthcare professional if: you are thinking about injecting CJC-1295 or another growth hormone peptide.
The only trials in healthy adults lasted 4 to 7 weeks and measured hormone levels, not muscle size or strength. We found no human trial that measured muscle with CJC-1295, so the muscle question has not been tested.
No study has tested whether CJC-1295 builds muscle in healthy adults; trials measured only hormone levels. Raising growth hormone on a blood test does not show that muscle grows.
In two placebo-controlled trials in 2006, healthy adults aged 21 to 61 got CJC-1295 injections for 28 or 49 days. Growth hormone rose 2 to 10 times and IGF-1, a related growth factor, rose 1.5 to 3 times, but the trials did not measure muscle or strength. The name CJC-1295 is used for more than one form of the substance, so a product sold under that name may not match the one tested, a naming problem FDA singled out in its 2026 peptide review.
- Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. Journal of Clinical Endocrinology and Metabolism. 2006;91(3):799-805. DOI: 10.1210/jc.2005-1536. PMID: 16352683
- US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. Content current as of April 22, 2026
- US Food and Drug Administration. Pharmacy Compounding Advisory Committee meeting, July 24, 2026: FDA presentations. FDA document 193774
- aidsmap. Lipodystrophy study halted after patient death. July 2006
- World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. In effect January 1, 2026