CJC-1295 and ipamorelin side effects: what the published trials report

What the CJC-1295 human trials reported

Teichman and colleagues (2006) ran two randomised, placebo-controlled, double-blind ascending-dose trials of CJC-1295 in healthy adults aged 21 to 61. The first gave a single subcutaneous injection at one of four dose levels; the second gave two or three doses at weekly or fortnightly intervals, with the trials lasting 28 and 49 days. The published conclusion is that subcutaneous CJC-1295 was safe and relatively well tolerated, particularly at 30 or 60 µg/kg, and that no serious adverse reactions were reported.

The same paper explains why the tolerability window matters. A single injection raised mean growth hormone (GH) two- to ten-fold for six days or more, and IGF-I 1.5- to three-fold for nine to eleven days. The estimated half-life was 5.8 to 8.1 days, and after repeated doses IGF-I stayed above baseline for up to 28 days. The compound is still active long after the injection, so anything it does to you is not confined to the day you inject.

That conclusion covers healthy adults, ascending doses and periods measured in weeks. It does not cover long-term use, people with existing endocrine, metabolic or cardiovascular conditions, or doses outside the tested range, because none of those were studied. The published abstract does not itemise individual adverse events, so we do not list any here.

The pulsatility question

Growth hormone is normally released in pulses, and the theoretical concern with any long-acting GHRH analogue is that continuous stimulation might flatten that rhythm. Ionescu and Frohman (2006) tested exactly this. Healthy men aged 20 to 40 had blood sampled every 20 minutes across a 12-hour overnight period, before and one week after a single injection of 60 or 90 µg/kg CJC-1295. The frequency and size of GH pulses were unchanged. What rose was the basal level between pulses, by 7.5-fold, which lifted mean GH by 46% and IGF-I by 45%. The two doses did not differ.

That answers one specific mechanistic question. It is not an adverse-event study and reports no clinical outcomes, so it tells you the rhythm survives a single dose in healthy men.

Ipamorelin: one surgical trial and a selectivity argument

The only placebo-controlled human safety data for ipamorelin that we can point to come from Beck and colleagues (2014), a phase 2 proof-of-concept trial in adults recovering from small or large bowel resection. Across multiple centres, patients received intravenous ipamorelin at 0.03 mg/kg or placebo twice daily from the first day after surgery, for up to seven days or until discharge. Of 117 enrolled, 114 formed the safety population. Treatment-emergent adverse events were recorded in 87.5% of the ipamorelin group and 94.8% of the placebo group, and the authors concluded the regimen was well tolerated. It did not significantly shorten the time to a first tolerated meal (25.3 versus 32.6 hours).

Read those percentages carefully. Nearly everyone on a post-operative ward reports some adverse event, which is why the placebo arm ran higher than the treatment arm; the comparator is what lets you see that. What the trial cannot tell you is how ipamorelin behaves when given subcutaneously, in healthy people, or for longer than a week, because it tested none of those.

The selectivity claim that ipamorelin is usually described by is older and preclinical. Raun and colleagues (1998) characterised it as the first growth hormone secretagogue that released GH without significantly raising ACTH or cortisol, even at more than 200 times the effective GH-releasing dose, and without affecting FSH, LH, prolactin or TSH. That work was done in rat pituitary cells, anaesthetised rats and conscious swine. It is a receptor-level argument for a cleaner hormonal profile, not a human adverse-event record.

What is not known

Three gaps are worth naming. No published human trial has given CJC-1295 and ipamorelin together, so any interaction between a GHRH analogue and a ghrelin-receptor agonist in the same person is uncharacterised. No human study of either compound extends beyond 49 days. And because neither is an authorised medicine, there is no pharmacovigilance system collecting reports from everyday use, which is how the rare or delayed effects of approved drugs are usually found. Absence of reported adverse events in short trials of small groups reflects the limit of what those trials could detect; it is not evidence of long-term safety. Where a study has not looked, nobody knows; those are questions for a clinician who knows your history.

The rationale for pairing the two is mechanistic: CJC-1295 acts through the GHRH receptor and ipamorelin through the ghrelin receptor, two routes to the same GH release. Our CJC-1295 versus ipamorelin comparison covers that pairing logic. This page covers only what has been measured in people.

The pen we sell

We sell CJC-1295 and ipamorelin in one combined pre-loaded pen, CJC-1295 & IPAMORELIN 20 mg in 3 ml, with the peptide already in solution. We supply the two together in one pen; we do not sell either on its own. Each pen ships with eight threaded pen needles, a printed guide and a verification sticker, in insulated packaging with a cooling element and a temperature indicator so it stays at 2–8 °C from our Czech dispatch point to your refrigerator, inside discreet outer packaging.

Every batch is tested by an independent laboratory for identity by mass spectrometry, purity by HPLC and sterility. Scan the QR code on the pen, or open the COA index, to read the certificate for your batch. None of that testing is clinical evidence: it tells you what is in the pen, not how your body responds to it. Buying requires an account and the short eligibility quiz, and we ship to adults aged 18 and over.