CJC-1295 vs sermorelin
Last updated: October 3, 2026 · 5 min read · By the Grey Peptides Editorial Board
- Both start from the same 29 amino acids of growth hormone-releasing hormone. CJC-1295 adds a chemical anchor that bonds it to albumin in the blood, stretching its half-life from minutes to about a week.
- CJC-1295 has two small 2006 studies in healthy adults and was never approved; the FDA records serious adverse events with it, and products sold under the name have not always contained it.
- Sermorelin was an approved paediatric drug, now discontinued. Both are banned in sport under S2.2.4.
Side by side
CJC-1295 Medium and sermorelin Medium are built on the same active fragment of growth hormone-releasing hormone, GHRH(1-29). Sermorelin is that fragment with an amide at its end. CJC-1295 modifies it and attaches a maleimide group that bonds to albumin after injection; the chemists who designed it made three such versions and picked the one that gave the most growth hormone in rat pituitary cells 1. The table is read from our encyclopedia entries.
| Field | CJC-1295 | Sermorelin |
|---|---|---|
| Encyclopedia entry | CJC-1295 Full entry | Sermorelin Full entry |
| Molecule class | Peptide | Peptide |
| Category | Growth Hormone | Growth Hormone |
| FDA status | Discontinued | Discontinued |
| Approved elsewhere | None recorded | None recorded |
| Evidence grade | Medium | Medium |
| Half-life | 5.8–8.1 days (with DAC) | Not established in our sources |
| Formula | C165H269N47O46 | C149H246N44O42S |
| Molecular weight | 3,647.2 g/mol | 3,357.9 g/mol |
| WADA 2026 | Prohibited at all times (S2.2.4) | Prohibited at all times (S2.2.4) |
| WADA 2027 | Prohibited at all times (S2.2.4) | Prohibited at all times (S2.2.4) |
| In one line | A long-acting GHRH analog engineered with a DAC linker that binds serum albumin, extending half-life from minutes to approximately 8 days. | GHRH's first 29 amino acids, sold in the US as Geref (approved 1990 and 1997) to test and treat childhood growth hormone deficiency until it was discontinued, not for safety reasons. |
| Mechanism | GHRH(1-29) analogue with four substitutions and a maleimidopropionamide-lysine that bonds covalently to albumin after injection, keeping it in circulation for days. In healthy adults it raised growth hormone for six days or more and IGF-1 for up to 11 days, with growth hormone pulses preserved and trough levels raised. | GHRH receptor agonist: the 29-amino-acid active fragment of GHRH, which stimulates growth hormone secretion from the anterior pituitary. Used as a 1 µg/kg intravenous test of pituitary reserve (a normal response cannot exclude hypothalamic deficiency) and, as Geref, as a nightly treatment for children with idiopathic growth hormone deficiency. |
| Sources in the entry | 9 | 9 |
| Study cards | 8 | 6 |
| Dosage page | Dosage page | Dosage page |
What the albumin bond changes
Bonding to albumin protects the peptide from the enzyme that normally breaks GHRH down within minutes and keeps it circulating: our entry gives CJC-1295's half-life as 5.8 to 8.1 days 2. In two randomised, placebo-controlled trials in healthy adults aged 21 to 61, a single injection raised mean growth hormone two- to tenfold for six days or more, and IGF-1 rose for longer 3. A study in healthy men sampling blood every 20 minutes overnight found that a week after a dose, growth hormone pulses kept their frequency and size, but trough levels rose 7.5-fold and mean growth hormone rose 46% 4. That is the core difference: sermorelin produces a short burst, CJC-1295 a sustained rise on top of the normal rhythm.
Status and safety signals
CJC-1295 was never approved. According to our entry, its US compounding nomination was withdrawn and the FDA records serious adverse events associated with it, including increased heart rate and a systemic vasodilatory reaction 2. Its human data stop at the two 2006 studies 3 4. There is also a product problem: a preparation seized by Norwegian police and customs in 2009 and sold as CJC-1295 contained a 29-amino-acid peptide consistent with a different product then marketed under that name 5, so what is in a vial labelled CJC-1295 may not be the molecule in the trials.
Sermorelin, by contrast, was approved as Geref for diagnosing and treating growth hormone deficiency in children; both products were discontinued, and the FDA determined in 2013 that this was not for safety or effectiveness reasons 2. Its human studies are paediatric diagnostic and short dosing studies 6.
'With DAC' and 'without DAC'
Online, CJC-1295 is often sold in two forms, "with DAC" and "without DAC". The albumin-binding design described in the 2005 chemistry paper and tested in the 2006 trials is the long-acting form 1 3. A version without the albumin anchor would behave much more like sermorelin, with a short half-life; it is usually sold as Mod GRF 1-29, which has its own entry, and the 2006 trials did not test it. Anyone comparing the two should know which one a product claims to be, and that the claim is not verified.
What the animal and doping studies add
Two further lines of work explain why CJC-1295 interests both researchers and anti-doping laboratories. In mice lacking the GHRH gene, injections every 24 hours from one week of age for five weeks produced normal body weight and length, every-other-day dosing gave normal bone length, and dosing every 72 hours gave partial improvement, which shows the long action in a living animal 7. The same albumin bond that makes it long-acting makes it hard to find in drug tests: a horse-racing laboratory had to capture it from plasma with antibodies, digest it and analyse the fragments by mass spectrometry to confirm it 8. Sermorelin, which clears in minutes, has no comparable long-acting profile.
How the differences add up (as of October 3, 2026)
CJC-1295 trades sermorelin's short action for a week-long rise in growth hormone and IGF-1, with two small studies, no approval, recorded serious adverse events and uncertain product identity. Sermorelin has a discontinued paediatric approval and an older, narrower record. Neither has evidence for the adult uses it is sold for, and both are prohibited in sport under S2.2.4 2. Doses on this page are those in our entries' sources, not recommendations.
Frequently asked questions
What is the difference between CJC-1295 and sermorelin?
Both use the same 29 amino acids of GHRH. CJC-1295 adds an anchor that bonds it to albumin, giving a half-life of about 6 to 8 days; sermorelin lasts minutes.
Is CJC-1295 safe?
It was never approved, its human data are two small 2006 studies, and the FDA records serious adverse events with it, including increased heart rate and a vasodilatory reaction.
Is sermorelin approved?
It was approved as Geref for children with growth hormone deficiency; both products are discontinued.
Related on Grey Peptides
Sources
- Jetté, L., et al. (2005). Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology, 146(7), 3052-8. PMID: 15817669
- Grey Peptides dataset records for both compounds (status, half-life and studied doses as sourced on each entry); read October 2, 2026.
- Teichman, S. L., et al. (2006). Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab, 91(3), 799-805. PMID: 16352683
- Ionescu, M., et al. (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab, 91(12), 4792-7. PMID: 17018654
- Henninge, J., et al. (2010). Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation. Drug Test Anal, 2(11-12), 647-50. PMID: 21204297
- Prakash, A., et al. (1999). Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs, 12(2), 139-57. PMID: 18031173
- Alba, M., et al. (2006). Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. Am J Physiol Endocrinol Metab, 291(6), E1290-4. PMID: 16822960
- Timms, M., et al. (2019). A method for confirming CJC-1295 abuse in equine plasma samples by LC-MS/MS. Drug Test Anal, 11(8), 1248-1257. PMID: 30938069
Educational information, not medical advice. Each dose in this guide names its source, an approved label or a published study. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose.
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