Sermorelin vs CJC-1295 Side-Effect Profile Head-to-Head

What safety data exist for each peptide?

Sermorelin's main human safety data come from a 1-year, open-label, multicenter trial of 110 previously untreated prepubertal children with growth hormone deficiency, who received 30 micrograms per kg subcutaneously at bedtime; 86 children were evaluable for efficacy [3]. Safety measures were monitored every 3 to 6 months. No adverse changes appeared in general biochemical or hormonal analyses, fasting glucose did not change, IGF-I was not excessively raised, and the peptide was well tolerated overall [3].

CJC-1295's record is much thinner. FDA's review identified only three published human studies of CJC-1295, all of the DAC form and all in healthy volunteers (Teichman 2006, Ionescu and Frohman 2006, Sackmann-Sala 2009), and found no study of any form in people with a disease [1]. No trial tested the version sold as CJC-1295 without DAC [1].

Sermorelin side effects: what the 1-year trial recorded

The routine blood and hormone panels in the pediatric trial showed no adverse changes, fasting glucose was unchanged, and IGF-I was not driven excessively high over 12 months [3]. Height velocity rose from 4.1 cm a year at baseline to 8.0 cm a year at 6 months and 7.2 cm a year at 12 months [3].

Adult data are physiology, not safety data. In one study, 10 healthy men with a mean age of 68 received 0.5 mg and 1 mg of GHRH(1-29) subcutaneously twice daily for 14 days each; at the higher dose, 24-hour GH and IGF-I rose to levels not significantly different from those of 9 young men [8]. That was a short physiology study, not a clinical-benefit trial [8].

CJC-1295 side effects: what the healthy-volunteer studies found

Teichman 2006 ran two randomized, placebo-controlled, double-blind, ascending-dose trials lasting 28 and 49 days in healthy adults aged 21 to 61. The first gave single doses (35 treated subjects and 7 on placebo); the second gave two or three weekly or biweekly doses [1][2].

In FDA's summary of that trial, injection-site reactions occurred in about 70% of treated subjects in study 1 and in all treated subjects in study 2. Headache occurred in 63% versus 14% on placebo in study 1. Flushing, warmth and transient low blood pressure occurred in about 30% of treated subjects in study 1, along with transient diarrhea, and two subjects had transient dizziness with low blood pressure. Most events were more common at the higher doses of 125 or 250 micrograms per kg. No serious adverse reactions were reported [1][2].

Heart rate, blood pressure and injection sites

Ionescu and Frohman 2006 gave healthy men aged 20 to 40 a single injection of 60 or 90 micrograms per kg. No serious adverse events occurred; the study reported dose-dependent increases in heart rate and transient injection-site redness and tenderness [1].

A week after that injection, GH was still being released in pulses of unchanged frequency and size, while between-pulse GH had risen about 7.5-fold and mean GH by 46%, with IGF-I up 45% [9]. So GH pulsatility was preserved in this study [9].

FDA's page on bulk substances that may present significant safety risks lists increased heart rate and a systemic vasodilatory reaction among the serious adverse events associated with CJC-1295, and states that the available clinical data are limited [10].

The phase 2 trial that stopped early

ConjuChem withdrew CJC-1295 DAC from clinical trials in 2006 after a participant in a phase 2 trial in HIV-associated lipodystrophy, which enrolled 192 people, died. FDA cites anecdotal news reports: 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]. A trial in HIV-associated visceral obesity listed on ClinicalTrials.gov as NCT00267527 was also terminated [1].

How long each peptide keeps GH raised

CJC-1295 DAC binds albumin, so its half-life is measured in days. After one subcutaneous injection the estimated half-life was 5.8 to 8.1 days, 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 [2].

Sermorelin is the opposite shape. After an intravenous dose in healthy men it was rapidly eliminated, yet GH stayed raised for about 3 hours [6].

The risk both peptides share: high GH and IGF-I

FDA's stated concern about growth-hormone-raising peptides is that GH and IGF-I elevation carries the risks listed on approved growth hormone labels, for example glucose intolerance and diabetes, fluid retention, and tumor growth concerns. FDA also said the CJC-1295 human studies were short, small and mostly single-dose, so long-term safety is unknown [1].

Over 12 months in children, sermorelin did not change fasting glucose or raise IGF-I excessively [3]. A single CJC-1295 DAC injection raised mean IGF-I 1.5- to 3-fold for 9 to 11 days, and repeated doses kept it above baseline for up to 28 days [2].

Regulatory status of each product

Sermorelin was FDA-approved as Geref under two applications: a 0.05 mg ampule for testing the pituitary's ability to release GH, originally approved December 28, 1990, and 0.5 mg and 1 mg vials for treating idiopathic GH deficiency in children with growth failure, originally approved September 26, 1997 [4]. The manufacturer discontinued both in 2008 and asked FDA to withdraw the applications, which FDA did effective June 18, 2009. In March 2013 FDA determined that Geref was not withdrawn for reasons of safety or effectiveness [4]. Geref was never approved for adults, anti-aging, weight loss or athletic performance [4].

With Geref gone, sermorelin sold in the US today is compounded, and compounded drugs are not FDA-approved: FDA does not review their safety, effectiveness or quality before they are marketed [5]. Sermorelin is not on FDA's list of bulk substances that may present significant safety risks [10]. Sermorelin acetate appears on FDA's nominated list for outsourcing facilities in category 1 (under evaluation), marked as a bulk substance that is a component of FDA-approved drugs [11].

CJC-1295 has never been approved anywhere FDA searched, and none is authorized by the European Medicines Agency [1]. It sits on FDA's nominated-but-withdrawn table: it had been in category 2 for significant safety risks, then came off when the nominators withdrew. FDA's stated concerns remain on that page, including 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]. It is in none of the three categories on FDA's list for state-licensed pharmacies and physicians and is not on the list for outsourcing facilities [12][11]. In December 2024 FDA reviewers proposed that no CJC-1295 form be added to the pharmacy bulks list, and the Pharmacy Compounding Advisory Committee voted 0 yes and 13 no on the free base, 1 yes and 12 no on the acetate, and 0 yes and 13 no on each DAC form [13].

Sport

Both peptides are named in section S2.2.4 of WADA's 2026 Prohibited List as growth hormone-releasing factors and their analogues. Both are prohibited at all times, in and out of competition, and both appear again in the 2027 List that takes effect January 1, 2027 [7][14].