A lot of peptide protocols circle the same idea: instead of injecting growth hormone itself, nudge your own pituitary to release more of it. Four peptides come up most. They are not interchangeable, and the evidence behind them ranges from one FDA-approved product to compounds with little modern human data. Here's the honest map.
Two ways to nudge growth hormone
There are two levers. GHRH analogs copy the natural release signal your hypothalamus sends the pituitary — sermorelin, CJC-1295 and tesamorelin all work this way. Ghrelin-receptor agonists, also called GHRPs, pull a different lever that adds a clean pulse on top — ipamorelin is the selective, cortisol-neutral example. That is why CJC-1295 and ipamorelin are so often paired: one sets a baseline, the other adds the pulse.
Side by side
- Sermorelin — a GHRH analog (the 1-29 fragment). The oldest of the group, with little modern adult outcome data. Not FDA-approved for these uses.
- CJC-1295 — a long-acting GHRH analog; limited human data, not FDA-approved. Often the base of a stack.
- Ipamorelin — a selective ghrelin-receptor agonist that adds a clean growth-hormone pulse without raising cortisol or prolactin. Limited human data, not FDA-approved.
- Tesamorelin — a GHRH analog, and the only FDA-approved one here: approved to reduce excess abdominal fat in people with HIV-associated lipodystrophy. The strongest evidence of the four, for that specific use.
The honest headline: of the four, only tesamorelin is FDA-approved, and only for a specific population. The others are used in compounded peptide therapy on the strength of mechanism and limited data, not large human trials.
Why they get combined
Because the two levers are complementary. A GHRH analog sets a steady background signal; a GHRP adds a sharp pulse. Together they are meant to produce a release pattern closer to the body's own than either alone. That rationale is mechanistic, not the result of a head-to-head trial of the combination.
None of these is a substitute for prescribed growth hormone, and none should be assumed safe long-term. Human safety data is limited for all but tesamorelin, and growth-hormone secretagogues are prohibited in sport. Anything compounded is not FDA-approved.
Keep reading: the evidence on CJC-1295, sermorelin, tesamorelin and ipamorelin, and the Build blend that pairs two of them.
Sources
The primary sources behind this article — so you can read them yourself.
- Tesamorelin — graded evidence & primary sources — New Start MD
- CJC-1295 — graded evidence & primary sources — New Start MD
- WADA Prohibited List — World Anti-Doping Agency
- Drugs@FDA (official labels) — U.S. Food and Drug Administration
Products are available only by prescription after a consultation with a licensed provider, who decides whether treatment is appropriate. Many compounds described here are not FDA-approved medicines and have not been tested in people for the uses described; information on this site is educational and is not medical advice.