CJC-1295 vs Ipamorelin: How They Differ, What the Evidence Shows and Lab Results

The main difference is the receptor each one switches on. CJC-1295 is a long-acting analog of growth-hormone-releasing hormone (GHRH), while ipamorelin is a small peptide that activates the ghrelin receptor. Both prompt the pituitary to release growth hormone, and neither is approved by FDA or any other regulator for any use. They are frequently sold and talked about together, but no published human study has tested the two in combination.

At a glance

How they work differently

Your pituitary gland has two separate "release growth hormone" switches. One is the GHRH receptor, which the brain's own growth-hormone-releasing hormone uses. The other is the ghrelin receptor, the one the stomach hormone ghrelin uses.

CJC-1295 works through the first. Natural GHRH is cleared from the blood within minutes, so ConjuChem, the Canadian company that developed CJC-1295, built a version with a chemical tail that hitches the peptide to albumin. That is the "DAC" (drug affinity complex) form. In healthy adults, a single injection of it kept growth hormone elevated for six days or more, with an estimated half-life of roughly six to eight days (Teichman et al. 2006, J Clin Endocrinol Metab). A follow-up study found that the body's natural pulses of growth hormone were preserved, while the low points between pulses rose (Ionescu and Frohman 2006). "Without DAC" lacks the tail. FDA's reviewers describe it as a separate form and note that the two get confused in listings (FDA briefing document, December 2024).

Ipamorelin works through the second switch. Novo Nordisk researchers derived it from an older growth-hormone-releasing peptide and described it in 1998. In that paper, ipamorelin acted through a receptor of the growth-hormone-releasing-peptide type and, unlike two related compounds, did not raise the stress hormones ACTH and cortisol in swine (Raun et al. 1998, Eur J Endocrinol). A 1999 human study in healthy men found it produces one short burst of growth hormone, peaking in under an hour, with a blood half-life of about two hours (Gobburu et al. 1999, Pharm Res).

Both act on the pituitary, so both need it to have some capacity left to respond. FDA's ipamorelin review says ipamorelin would not be expected to raise growth hormone in people with absent pituitaries or severely damaged growth-hormone-producing cells (FDA briefing document on ipamorelin, October 2024), and the CJC-1295 researchers likewise limited their conclusions to people with intact pituitary growth hormone secretion (Ionescu and Frohman 2006).

What the evidence shows

No head-to-head trial exists. We searched PubMed on September 30, 2026 for any published study that gave both compounds to people, and found none, only narrative reviews and doping-analysis papers. Comparing numbers from separate studies is unreliable, because they used different people, timelines and outcomes. So here is each compound's best evidence, briefly. The full versions are in our CJC-1295 guide and ipamorelin guide.

CJC-1295. The human evidence is a set of small studies in healthy adults, all with the DAC form. In the two placebo-controlled trials, growth hormone and IGF-1 rose, and the authors reported no serious adverse reactions (Teichman et al. 2006). FDA found no study of any form of CJC-1295 in people with a disease or condition, including growth hormone deficiency (FDA briefing document, December 2024). Nobody has published a trial showing a benefit for muscle, fat loss or recovery.

Ipamorelin. Beyond the 1999 pharmacology study, the only controlled human trial tested it for recovery of bowel function after abdominal surgery. In 114 analyzed patients, the time to tolerating a solid meal was about 25 hours with ipamorelin versus about 33 hours with placebo, a difference that was not statistically significant, and none of the secondary measures differed either (Beck et al. 2014, Int J Colorectal Dis). A later paper summarized the outcome as disappointing and said development for that use was discontinued (quoted in FDA's briefing document). FDA identified no data supporting ipamorelin for growth hormone deficiency either.

Put plainly, the evidence for both is that they raise growth hormone in healthy people. Neither has a published trial showing a downstream benefit that buyers commonly claim. A June 2026 narrative review sorted growth-hormone-axis peptides into evidence tiers running from randomized-trial data down to no human studies, and stressed the uncertainty around product composition and how people use them (Dominikowski et al. 2026, Front Endocrinol).

Side effects and risks compared

The two have different risk pictures, mostly because they have been studied differently.

CJC-1295. In FDA's summary of the healthy-volunteer studies, 33 of 35 people (94%) given the DAC form in one trial reported at least one adverse event, versus 2 of 7 on placebo. Injection-site reactions affected about 70%, headache 63% (versus 14% on placebo), and about 30% had flushing, warmth or a transient drop in blood pressure. These were more common at higher amounts (FDA briefing document, December 2024).

The bigger question mark is the 2006 Phase 2 trial in people with HIV. ClinicalTrials.gov lists it as sponsored by ConjuChem, terminated in September 2006 (NCT00267527). FDA's memo relays press reports that a participant had a fatal heart attack; the physician's stated explanation was undiagnosed coronary artery disease, and the data were never published. FDA's memo makes clear those details come from anecdotal reports, and cause was never established either way.

FDA's advisory committee met on December 4, 2024 and voted against adding CJC-1295 forms to the list for compounding: 13 against for the free base and the DAC forms, and 12 against, 1 in favor, for the acetate (summary minutes). Those are advisory votes on compounding eligibility, not a safety finding on their own.

Ipamorelin. In the surgical trial, adverse events were reported by 87.5% on ipamorelin and 94.8% on placebo, and the authors concluded it was well tolerated (Beck et al. 2014). That was a short hospital course in surgical patients, so it says little about anything else. FDA's review of the same trial notes serious adverse events in 17.9% of ipamorelin patients and 15.5% of placebo patients, including two deaths in the ipamorelin group after bowel-resection complications (whether the drug played a role is unclear), and more hypokalemia (12.5% versus 3.4%) and hyperglycemia at discharge (14.3% versus 8.6%) on ipamorelin. Beyond that, FDA's review raises theoretical concerns. Ghrelin receptors sit in brain reward regions, and the ghrelin class could in principle affect reward processing. A mouse study of ghrelin found effects on fertilization and early embryo development, and FDA says it remains to be determined whether ipamorelin does the same. FDA also called the available nonclinical toxicity studies "too limited in scope and duration," and found two non-serious adverse-event reports tied to compounded products (FDA briefing document, October 2024). On October 29, 2024, its advisory committee voted 0 in favor, 12 against, 1 abstaining on listing either form for compounding (summary minutes). FDA's bulk substances page, current as of April 22, 2026, still lists ipamorelin acetate in Category 2 for 503B outsourcing facilities (added September 29, 2023), while CJC-1295 appears under nominations that were withdrawn.

What the lab tests show

These figures come from independent lab reports, mostly commissioned by buyers, as of September 30, 2026, and count only vendors we can identify. Our failure definition is an empty vial, purity under 95%, more than 20% under label, or more than 50% over.

Ipamorelin: 20 vials from 12 vendors, about 18 reports, January 2025 to August 2026. Median purity was 99.77%. Median dose came in 1.6% under label, unusual in our data, where most compounds skew over. Six vials were within 5% of label and ten within 10%; two were more than 20% under and one more than 20% over. Two of 20 vials (10%) failed.

CJC-1295: the numbers are thinner and split by form. With DAC: 7 vials, 5 vendors, median purity 99.33% with one vial under 95%, median dose 1.2% over label, one vial more than 20% under, and 2 failed. Without DAC: 6 vials, 4 vendors, median purity 99.28%, median dose 0.6% over label, one vial more than 50% over, and 1 failed. Two more vials were sold as pre-mixed blends, too few to say anything.

With samples this small, one vendor can move every figure, and the numbers cannot rank one compound against the other. What you can say is that both are sold in varied forms and that naming is inconsistent, so it is worth knowing which molecule the label actually claims.

Ipamorelin has enough vials for a vendor table. CJC-1295 does not, so it has no ranked list yet. Here is who has the strongest independent lab record for ipamorelin right now. The table flags vendors with more than 5% failed vials, and a ranked vendor is not automatically a good one:

Buying smarter

Check the vendor's record for the specific compound: our ipamorelin results page and CJC-1295 results page show every report behind the numbers, and a vendor needs five or more lab reports before we rank them. Because listings use "CJC-1295," "with DAC," "without DAC" and "Mod GRF 1-29" inconsistently, a lab report that identifies the molecule matters as much as the purity number.

How to get a peptide tested covers ordering identity, purity and quantity testing on your own vial. A vendor's posted COA is a starting point, not proof, so cross-check it with how to read a peptide COA and fake peptide COAs. If a report comes back failed, stop using that batch, tell anyone who bought from the same run, bring the report to the vendor, and submit it to VendorVerify.

Database figures without a date update automatically from VendorVerify's lab results; dated figures are snapshots. This isn't medical advice; both compounds are sold for research use only and neither has been approved by FDA for any use.