Ipamorelin + CJC-1295 Stack: Evidence, Mechanism, and Protocol

What the two peptides are

Ipamorelin is a five-amino-acid synthetic peptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) containing unnatural amino acids, identified in 1998 [3][2]. CJC-1295 is an investigational long-acting analogue of growth hormone-releasing hormone, first described in 2005, and has never been approved in any country FDA searched [1][5].

FDA describes two forms of CJC-1295: a 29-amino-acid GHRH analogue, and CJC-1295 DAC, which is that peptide with an extra maleimidopropionic acid-lysine unit at the C-terminal end that lets it bind albumin in blood and last much longer [1]. The preclinical paper that named it describes a tetrasubstituted form of GHRH(1-29) with the added lysine unit, detectable in rat plasma beyond 72 hours [5].

Do they work through different receptors?

Yes. Ipamorelin and CJC-1295 act through different receptor systems involved in growth hormone release [1][3]. Ipamorelin stimulates growth hormone release at the ghrelin/growth hormone secretagogue receptor, not at the GHRH receptor [3]. In rat pituitary cells it released GH with potency and efficacy similar to GHRP-6; in anesthetised rats and in conscious swine it also matched GHRP-6, and in swine it did not change FSH, LH, prolactin or TSH [3]. Most of what is said about ipamorelin's selectivity comes from that animal work.

CJC-1295 acts like GHRH on the pituitary to raise the body's own GH and, through GH, IGF-I [6][7]. Because the DAC form binds albumin, its half-life after a single subcutaneous injection was estimated at 5.8 to 8.1 days in healthy adults [6].

What the human CJC-1295 studies actually show

FDA identified only three published human studies of CJC-1295, all of the DAC form and all in healthy volunteers, and no study of any form in people with a disease [1].

Teichman and colleagues ran two randomized, placebo-controlled, double-blind, ascending-dose trials lasting 28 and 49 days in healthy adults aged 21 to 61, with single doses in the first and two or three weekly or biweekly doses in the second [6]. After one injection, mean plasma GH rose 2- to 10-fold for 6 days or more and mean IGF-I rose 1.5- to 3-fold for 9 to 11 days; after multiple doses, IGF-I stayed above baseline for up to 28 days [6]. FDA counted 35 treated subjects and 7 on placebo in the first trial [1].

Ionescu and Frohman gave healthy men aged 20 to 40 a single injection of 60 or 90 micrograms/kg [7]. A week later, GH pulse frequency and size were unchanged, but trough GH between pulses had risen about 7.5-fold, mean GH by 46% and IGF-I by 45%, with no difference between the two doses [7].

A phase 2 trial ended after a participant's death

ConjuChem withdrew CJC-1295 DAC from clinical testing in 2006 after a participant in a phase 2 trial in HIV lipodystrophy, which enrolled 192 people, died [1]. FDA's account, drawn from news reports, is that the person had chest discomfort 2 hours after an 11th weekly dose, an ECG showed an acute heart attack, and the attending physician's most likely explanation was undiagnosed coronary artery disease with plaque rupture; the data were never published, so a causal link is neither shown nor excluded [1].

What the human ipamorelin studies actually show

Ipamorelin's human data are intravenous and short. A phase 2 trial in 117 adults having bowel resection, 114 analyzed, gave 0.03 mg/kg IV twice daily from postoperative day 1 to 7 or discharge [8]. Median time to a first tolerated solid meal was 25.3 hours on ipamorelin versus 32.6 hours on placebo (p=0.15), a difference that was not statistically significant, and secondary recovery endpoints did not differ [8]. Development was reportedly discontinued after disappointing phase 2 results [2].

A volunteer study infused 4.21 to 140.45 nmol/kg over 15 minutes and found dose-proportional pharmacokinetics, a terminal half-life of about 2 hours, and a single GH peak about 0.67 hours after the infusion [9]. FDA found no human pharmacokinetic, safety or efficacy data for subcutaneous ipamorelin [2].

Is there a standard protocol or dose?

No. Neither peptide has an FDA-approved dose [1][2]. The doses that appear in the literature are study doses:

• CJC-1295 DAC, healthy adults: single subcutaneous injections of about 30 to 250 micrograms/kg, or two to three doses given weekly or every two weeks [1][6].
• Ipamorelin: 0.03 mg/kg IV twice daily in the ileus trial, and single 15-minute IV infusions of 4.21 to 140.45 nmol/kg in the volunteer study [8][9].

None of these are recommended doses, and FDA noted the human studies were short, small and mostly single-dose [1]. FDA also noted that CJC-1295 sold online is mostly labeled research use only, including blends with ipamorelin, and that research-use-only products are not approved drugs [1].

What has been reported as harmful

In the Teichman trials, injection-site reactions occurred in about 70% of treated subjects in the first study and in all treated subjects in the second; headache 63% versus 14% on placebo; flushing, warmth and transient low blood pressure in about 30% of treated subjects in the first study; transient diarrhea; and transient dizziness with low blood pressure in two subjects [1][6]. Most events were more common at the higher doses of 125 or 250 micrograms/kg, and no serious adverse reactions were reported [1][6]. In the Ionescu study there were no serious adverse events, but heart rate rose with dose and injection sites were transiently red and tender [1].

FDA's compounding page lists its own remaining concerns about CJC-1295: possible immunogenicity for certain routes, impurity and characterization problems, serious adverse events including increased heart rate and systemic vasodilatory reaction, and limited clinical data [10].

For ipamorelin, the ileus trial reported low potassium in 12.5% on ipamorelin versus 3.4% on placebo, insomnia 10.7% versus 5.2%, high blood sugar at discharge 14.3% versus 8.6%, and serious adverse events 17.9% versus 15.5%; two ipamorelin-treated patients died of surgical complications, and FDA said it is unclear whether the deaths were related to the drug [2][8]. FDA also cites a published study that identified serious adverse events including death when ipamorelin was given intravenously to improve gastric motility, and states it has not identified safety information for other injectable routes [10].

FDA's concern about growth hormone-raising peptides generally is that GH and IGF-I elevation carries the risks listed on approved growth hormone labels — glucose intolerance and diabetes, fluid retention and tumor growth concerns among them — and that the human studies were short, small and mostly single-dose, so long-term safety is unknown [1]. CJC-1295 raised GH and IGF-I in its human studies [6]. Intravenous ipamorelin produced GH release in volunteers [9], and FDA warns that it may carry the same GH-label risks and, like the approved GH stimulator macimorelin, possibly QT prolongation, and that it found no data showing otherwise [2].

Regulatory status

Neither peptide is approved, and the advisory votes went against both. On December 4, 2024, FDA's Pharmacy Compounding Advisory Committee voted 0 yes and 13 no on CJC-1295 free base, 1 yes and 12 no on CJC-1295 acetate, and 0 yes and 13 no on each of the three DAC forms [11]. On October 29, 2024, the same committee voted 0 yes, 12 no with 1 abstention on both ipamorelin free base and ipamorelin acetate, citing a lack of information on safety and efficacy [12]. FDA's reviewers proposed that neither peptide be added to the list of bulk substances pharmacies may compound [11][12].

Ipamorelin acetate remains in FDA's category 2 — bulk substances that may present significant safety risks — for outsourcing facilities, a list it was added to on September 29, 2023 and was still on as of the page dated 04/22/2026 [10][13]. On the pharmacy side, ipamorelin's nominations were withdrawn and it sits in the nominated-but-withdrawn table [10]. CJC-1295 also sits in that table after its nominators withdrew, but FDA's safety concerns remain posted [10]. Neither is among the six peptides in HHS's October 2026 draft enforcement-discretion policy [14]. In sport, WADA names both in section S2.2.4, prohibited at all times, in and out of competition [4][15].