Sermorelin and CJC-1295 are often presented as alternatives — a "gentler" daily peptide and a "longer-acting" one — and sometimes the second is described as an improved version of the first. The structural part of that story is accurate. CJC-1295 is sermorelin with four amino acids replaced, and in one version a linker that changes its half-life from minutes to days. The evidence part is where the two diverge: one molecule once had a US label, and the other has a few dozen volunteers. This page sets out both, sourced and dated. It recommends nothing. How brands appear on this site is on our disclosure page.
Four letters apart
Human growth-hormone-releasing hormone (GHRH) is 44 amino acids long. Its first 29 carry the full biological activity, and that fragment, amidated at the end, is sermorelin. CJC-1295 keeps the same 29 positions and changes four:
| Position | Sermorelin (GHRH 1-29) | CJC-1295 | What the record shows about the swap |
|---|---|---|---|
| 2 | Ala | D-Ala | Measured alone in 10 men: clearance roughly halved (Soule 1994) |
| 8 | Asn | Gln | Not tested on its own in people |
| 15 | Gly | Ala | Not tested on its own in people |
| 27 | Met | Leu | Removes sermorelin's only sulfur-containing residue; not tested on its own in people |
The sequences are from UniProt's human GHRH record (P01286) and the CJC-1295 sequence printed in FDA's 2024 evaluation, which cites the substitutions at "positions 2, 8, 15 and 27". The formulas confirm the last swap: sermorelin is C149H246N44O42S (PubChem), CJC-1295 C152H252N44O42 (FDA), with no sulfur. Of the four changes, only the first has been tested on its own in people.
"CJC-1295 with DAC" adds a drug affinity complex: in FDA's description, a maleimidopropionamide-lysine unit at the C-terminus that bonds to the cysteine-34 residue of albumin in the blood, which is what holds the peptide in circulation for days. "CJC-1295 without DAC", also sold as modified GRF 1-29, is the four-substitution peptide alone.
Half-life: minutes, slightly more minutes, and a week
| Molecule | Measured half-life in people | Source |
|---|---|---|
| GHRH(1-29)-NH2 (sermorelin) | 4.3 ± 1.4 min disappearance half-time, IV infusion | Soule et al. 1994, 10 men |
| D-Ala2-GHRH(1-29)-NH2 (one of CJC-1295's four swaps) | 6.7 ± 0.5 min | Same study |
| CJC-1295 without DAC | No human measurement | FDA 2024: no study establishing pharmacological activity |
| CJC-1295 with DAC | 5.8–8.1 days (estimated) | Teichman et al. 2006 |
The one substitution measured in isolation cut clearance roughly in half (39.7 to 21 mL/kg/min) and lengthened the half-time by about 2.4 minutes. What the other three add, together, has not been published. The day-long figures in circulation for no-DAC products are not from a human study. The week-long figure is real, and it belongs only to the DAC form: in Ionescu and Frohman's 2006 study, a single 60 or 90 mcg/kg injection left trough growth hormone 7.5-fold higher a week later, with GH pulses unchanged in frequency and size, mean GH up 46% and IGF-1 up 45%.
Approval and evidence
Sermorelin was approved in the US as GEREF (EMD Serono): a diagnostic ampule and a treatment vial. Drugs@FDA lists both as discontinued, with FDA's note that they were not withdrawn for safety or effectiveness reasons. The labelled treatment was pediatric — about 30 mcg/kg under the skin at bedtime for idiopathic growth hormone deficiency — and the diagnostic dose 1 mcg/kg intravenously (Prakash and Goa, 1999). Three adult trials in the 1990s gave GHRH(1-29) or a close analogue for 2 to 16 weeks to older men and women. Today it is dispensed by compounding pharmacies; the figures they state are on our sermorelin dosage page.
CJC-1295 was developed by ConjuChem. Its human record, as FDA counted it in 2024, is 63 healthy adults across three studies, 87% men and 73% given a single injection, plus a phase 2 trial in HIV-associated abdominal fat that was terminated in 2006 after a participant's death and never published. FDA's evaluation recommended against adding any of five CJC-1295 forms to the 503A bulks list, citing incomplete characterisation, immunogenicity risk and the absence of evidence that the no-DAC form is active. The other GHRH comparison in that history is on our CJC-1295 vs tesamorelin page.
Doses in the record
| Sermorelin | CJC-1295 with DAC | |
|---|---|---|
| Labelled | 30 mcg/kg/day SC at bedtime (pediatric, discontinued); 1 mcg/kg IV (diagnostic) | None |
| Trials | Adults: 0.5–1 mg twice daily for 14 days; 2 mg nightly for 6 weeks; 10 mcg/kg nightly for 16 weeks (analogue) | Healthy adults: single doses 30–250 mcg/kg; 2–3 weekly or fortnightly doses |
| What clinics and pharmacies state | 0.2–0.3 mg nightly (compounding pharmacy pages, read 2026-09-23) | DAC: 1–2 mg once or twice weekly; no-DAC: 100 mcg rising to 200–300 mcg nightly with ipamorelin (clinic guide dated 2026-07-24) |
For a 70 kg adult, the CJC-1295 trial range of 30–250 mcg/kg is 2.1 to 17.5 mg in one injection; the 30–60 mcg/kg doses the authors called best tolerated are 2.1 to 4.2 mg. The clinic figure of 1–2 mg weekly sits below that. For the no-DAC form there are no trial figures to compare against at all.
Side effects, as each record reports them
Sermorelin. The 1999 review reports single intravenous and repeated daily subcutaneous doses as well tolerated, with transient facial flushing and injection-site pain the most common events. A 16-week adult trial of an analogue reported a transient rise in blood lipids. FAERS held 59 reports naming sermorelin on 2026-09-23, most frequently itching, nausea and hypersensitivity. Detail: our sermorelin side-effects page.
CJC-1295. In the first 2006 trial, FDA's summary reports adverse events in 33 of 35 treated volunteers against 2 of 7 on placebo: injection-site reactions about 70%, headache 63%, diarrhoea 43%, flushing or transient low blood pressure 30%, mostly at the higher doses. FAERS held 5 reports on 2026-09-24. Detail: our CJC-1295 side-effects page.
The records are not comparable rate for rate: different decades, populations, routes and doses. A week-long molecule and a minutes-long one also expose the body to growth-hormone stimulation in different shapes — continuous versus a nightly pulse — and no study has compared the two directly.
What the record does not contain
- A head-to-head study of CJC-1295 and sermorelin.
- Any human half-life, dose-response or safety data for CJC-1295 without DAC — the form most often sold, and usually sold with ipamorelin.
- Any trial of either molecule for muscle, fat loss, sleep or ageing in healthy adults beyond the small 1990s sermorelin studies.
- Published results from CJC-1295's only patient trial.
The CJC-1295 and ipamorelin pairing is covered on our CJC-1295 and ipamorelin dosage page, and the half-lives of the wider family on our peptide half-life page. What each molecule is, in plain terms, is in Peptide Lexicon's sermorelin and CJC-1295 entries. Decisions about any growth-hormone secretagogue belong with a clinician.
Sources and dates
- UniProt P01286 (human somatoliberin, GHRH) sequence; PubChem CID 16132413 (sermorelin, C149H246N44O42S, 3357.9 g/mol); read 2026-10-02.
- FDA. CJC-1295-related bulk drug substances, evaluation for the Pharmacy Compounding Advisory Committee meeting of 4 December 2024 (fda.gov/media/183819): structure, nonclinical and conclusion sections, read 2026-10-02.
- Soule S, King JA, Millar RP. Incorporation of D-Ala2 in growth hormone-releasing hormone-(1-29)-NH2 increases the half-life and decreases metabolic clearance in normal men. J Clin Endocrinol Metab 1994;79(4):1208-11 (PMID 7962295).
- Teichman SL et al. J Clin Endocrinol Metab 2006;91(3):799-805 (PMID 16352683). Ionescu M, Frohman LA. Pulsatile secretion of growth hormone persists during continuous stimulation by CJC-1295. J Clin Endocrinol Metab 2006;91(12):4792-7 (PMID 17018654).
- Prakash A, Goa KL. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs 1999;12(2):139-57 (PMID 18031173).
- Drugs@FDA NDA 019863 and NDA 020443 (GEREF), FAERS counts, and the compounding-pharmacy and clinic dose pages, as read for this site's sermorelin, CJC-1295 and CJC-1295/ipamorelin pages on 2026-09-23 and 2026-09-24.
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