CJC-1295 vs Ipamorelin: How They Differ, and What FDA Recorded on Each

CJC-1295 and ipamorelin both raise growth hormone, and they are usually sold together, but they work in different ways. CJC-1295 is a long-acting copy of growth hormone-releasing hormone (GHRH) that, in its original form, binds to albumin in the blood and lasts about a week.^[1][2] Ipamorelin is a small peptide that acts on the ghrelin receptor and produces one short burst of growth hormone, with a half-life of about two hours.^[4] Neither is FDA-approved, neither is in the HHS peptide policy of October 2026, and FDA’s records cite serious adverse events for both.^[6][10]

CJC-1295 vs ipamorelin at a glance

What each peptide is

Natural GHRH is released by the hypothalamus and tells the pituitary to release growth hormone, but its action is short, which limits its use as a drug.^[1] CJC-1295 was designed to fix that. In the version tested in people, a chemical linker binds the peptide to albumin, the main protein in blood, after injection, and its half-life was measured at 5.8 to 8.1 days.^[1][2] Sellers and reviewers now distinguish two products under the same name: CJC-1295 with that linker, called DAC (drug affinity complex), and CJC-1295 without it.^[12] The human studies below used the albumin-binding version.

Ipamorelin is a pentapeptide, five amino acids long, that its developers built from the GHRP family of growth hormone-releasing peptides. Those peptides act on what is now called the ghrelin receptor, separate from the GHRH receptor that CJC-1295 uses.^[3][5] Ipamorelin’s reputation as “selective” comes from the same 1998 paper: in pigs, it raised growth hormone without raising ACTH or cortisol, even at doses more than 200 times higher than needed for the growth hormone effect.^[3] That finding comes from animals. The human studies below measured growth hormone, not cortisol or prolactin.

The human evidence for each

CJC-1295: a week of raised growth hormone in healthy adults

Two randomized, placebo-controlled trials in healthy adults aged 21 to 61 tested single and repeated injections under the skin. After one injection, average growth hormone levels rose 2- to 10-fold for six days or more, and IGF-1, the hormone growth hormone drives, rose 1.5- to 3-fold for 9 to 11 days. With repeated doses, IGF-1 stayed above baseline for up to 28 days, and no serious adverse reactions were reported.^[1]

A follow-up study in healthy men aged 20 to 40 sampled blood every 20 minutes overnight, before and a week after one injection. The normal on-off pattern of growth hormone release was kept. What changed most was the baseline between pulses, which rose 7.5-fold; average growth hormone went up 46% and IGF-1 45%.^[2]

The developer then registered a 12-week phase 2 trial of CJC-1295 in people with HIV and abdominal fat. The record shows it was terminated in 2006, and no results were posted.^[9] We found no published trial testing CJC-1295 for body composition, recovery or any clinical outcome.

Ipamorelin: hormone modeling and a surgical trial

In the main human pharmacology study, eight healthy men at each of five dose levels received ipamorelin by IV infusion. It caused one episode of growth hormone release that peaked about 40 minutes after the infusion (0.67 hours) and faded, and its half-life was about two hours.^[4]

Ipamorelin’s largest trial was not about growth hormone. In a phase 2 trial, 114 patients recovering from bowel surgery received IV ipamorelin or placebo twice daily for up to seven days, to see whether their bowels would recover sooner. Patients on ipamorelin managed a solid meal after a median of 25.3 hours, against 32.6 on placebo, a gap the trial could not separate from chance (p = 0.15). Most patients in both arms had an adverse event: 87.5% on ipamorelin, 94.8% on placebo.^[5]

Both peptides raise growth hormone in people. Neither has a published trial showing that this improves body composition, recovery or anything else.

What FDA has recorded about each

The two sit in different places in FDA’s compounding records, and neither place is reassuring.

• CJC-1295. FDA’s safety-risk page lists it among withdrawn nominations. The agency says it found serious adverse events tied to CJC-1295, naming a faster heart rate and a body-wide widening of blood vessels, and that clinical data on the peptide are limited.^[6] In December 2024 FDA’s Pharmacy Compounding Advisory Committee voted on five forms of CJC-1295 for the 503A bulks list, which had been nominated for growth hormone deficiency. The votes were 13 to 0 against the free base, 12 to 1 against the acetate and 13 to 0 against each of the three DAC forms.^[8]
• Ipamorelin. Since September 29, 2023, ipamorelin acetate has sat in FDA’s active Category 2 for 503B outsourcing facilities, the group of bulk substances flagged for possible significant safety risks. FDA points to possible immune reactions, to unnatural amino acids that complicate testing what a vial holds, and to a published study of IV ipamorelin for stomach emptying in which serious adverse events, deaths among them, were reported.^[6]
• Both. Neither peptide is on any of FDA’s three 503A nomination lists as of May 2026, so neither is a substance under evaluation for 503A compounding.^[7] Neither is among the six peptides in the October 28, 2026 HHS enforcement-discretion policy, so that policy gives a pharmacy no cover to compound them.^[10]

Both are banned in sport at all times, under the peptide-hormone section of the list rather than the one for anabolic steroids. The World Anti-Doping Agency names CJC-1295 under S2.2.4 as a GHRH analog and ipamorelin in the same section as a growth hormone secretagogue.^[13]

Safety: what is known and what is not

• Short trials only. The human CJC-1295 data cover weeks, not months, and the ipamorelin trial lasted up to seven days.^[1][5] Nothing is known about long-term use of either.
• Growth hormone effects. A 2026 review of peptides that act on the growth hormone axis lists the adverse effects reported with this class: rises in prolactin and cortisol, appetite changes, blood sugar problems, fluid retention, joint and muscle aches, and injection-site reactions.^[12]
• A long-acting peptide cannot be stopped quickly. CJC-1295’s week-long half-life means an unwanted effect can last days after the last dose.^[1] Ipamorelin clears within hours.^[4]
• Unknown contents. With no approval, no 503A listing and no HHS cover, most of what is sold online is research-use-only, with no certificate requirement and no prescriber. The difference is explained in research-use-only vs compounded peptides.

Why people combine them

Because they act on different receptors, a GHRH analog and a ghrelin-receptor peptide given together can release more growth hormone than either alone. That was shown in 1990 in 18 healthy men given single IV doses of GHRH and GHRP-6, an older peptide in ipamorelin’s family: low doses of the two together released growth hormone synergistically.^[11] That is the basis for the stack. No published study has given CJC-1295 and ipamorelin together, so the size of any combined effect, and its safety, are untested.

The HHS policy’s single-ingredient rule does not come into play here, because neither peptide is covered in the first place.^[10] For how the stack is marketed and what FDA wrote about it, see the CJC-1295 and ipamorelin stack. For how ipamorelin compares with the older GHRH analog that once had an FDA approval, see ipamorelin vs sermorelin. The oral pill that acts on the same receptor as ipamorelin is compared with growth hormone itself in MK-677 vs HGH.

To check where any other peptide stands, use our peptide status checker.