CJC-1295 and ipamorelin are sold as a pair on the theory that two different signals to the pituitary add up to more growth hormone than either alone. Each has a small amount of human data on its own. A search of PubMed and ClinicalTrials.gov finds no published study that gave the two together. The combination’s effect, and its safety, are an inference rather than a measurement.
Both are research-only on this site, which means this page describes what studies used and what they found, and nothing about what anyone should take. What a peptide is, in general terms, is in what are peptides.
Two receptors, one pituitary
The theory behind the pairing starts at the pituitary, which has separate receptors for two kinds of growth hormone signal. CJC-1295 is an analog of growth-hormone-releasing hormone, the same family as sermorelin, so it acts on the GHRH receptor [1]. Ipamorelin acts through a different receptor, the one used by the growth-hormone-releasing peptides [4].
That two receptors exist is established; that stimulating both at once with these two particular molecules gives a useful, safe result in people is the hypothesis, and it is the part no published trial has tested.
CJC-1295: what the 2006 studies measured
Two randomized, placebo-controlled, ascending-dose trials gave CJC-1295 by injection under the skin to healthy adults aged 21 to 61, over 28 and 49 days [1]. After one injection, mean growth hormone rose 2- to 10-fold for 6 days or more, and IGF-1 rose 1.5- to 3-fold for 9 to 11 days, with an estimated half-life of 5.8 to 8.1 days.
That long half-life comes from the molecule binding to albumin in the blood. A second study in healthy men aged 20 to 40, given 60 or 90 micrograms per kilogram, found the body’s normal pulses of growth hormone were preserved, while the baseline between pulses rose 7.5-fold and IGF-1 rose 45% [2]. No serious adverse reactions were reported in the first study, which measured hormone levels, not any health outcome.
One registered trial went further: a phase 2 study of CJC-1295 for 12 weeks in 120 people with HIV and excess abdominal fat. Its registry record lists it as terminated, with no results posted and no reason given [3].
Ipamorelin: what was measured
In healthy men given ipamorelin by 15-minute infusion, each dose produced a single pulse of growth hormone peaking at 0.67 hours, and the drug had a half-life of about 2 hours [4]. Its one published efficacy trial, after bowel surgery, found no significant benefit over placebo: median time to a tolerated meal was 25.3 hours on ipamorelin and 32.6 hours on placebo, p = 0.15 [6]. The full record is in ipamorelin’s human evidence.
What FDA has said about each
FDA’s page on bulk substances that may present significant safety risks addresses both [7]. For CJC-1295, the agency states it has identified serious adverse events, “including increased heart rate and systemic vasodilatory reaction,” and that available clinical data are limited. Its nomination for pharmacy compounding was withdrawn, leaving it on no 503A list. Ipamorelin sits in 503B Category 2, and FDA cites serious adverse events, including death, when it was given intravenously for gut motility.
Put the two records side by side and the gap is plain. One compound has hormone-level data from healthy volunteers and a terminated trial; the other has a dosing study and a trial that missed its goal. Neither record includes muscle, fat loss, sleep or recovery outcomes, and the combination has no record at all. The regulatory background is in are peptides legal, and approved options with trial evidence start at the recovery goal page.