Two ways to reach the same hormone
The pituitary releases growth hormone in pulses, and two hypothalamic signals set the size of those pulses. Growth-hormone-releasing hormone (GHRH) acts on the GHRH receptor and drives both synthesis and release. Ghrelin, the stomach hormone, acts on a different receptor (GHS-R1a) and amplifies the pulse. Everything in this class is an analogue of one or the other. GHRH analogues keep the natural pulsatile pattern, because release still waits for the pituitary's own rhythm; ghrelin mimetics add to whatever pulse is under way. The two receptors are additive, which is why the literature so often studies one of each together.
Native GHRH has a half-life of a few minutes, cleared mainly by the enzyme DPP-4. Each analogue below is a different engineering answer to that: protect the N-terminus, attach the peptide to albumin, or use a small synthetic peptide that binds the other receptor instead.
Side by side
| Compound | Receptor | Developer · code | Half-life | Status | What the cited human studies measured |
|---|---|---|---|---|---|
| CJC-1295 with DAC | GHRH receptor | ConjuChem · CJC-1295 | 5.8–8.1 days (Teichman 2006) | Investigational; development did not proceed to approval | In healthy adults a single dose raised growth hormone for at least six days and IGF-1 for nine to eleven days. Pulsatile release was preserved: trough and mean levels rose, pulse frequency did not change. |
| Ipamorelin | Ghrelin receptor (GHS-R1a) | Novo Nordisk · NNC 26-0161 | About two hours (Gobburu 1999) | Investigational; later evaluated for postoperative ileus, not approved | In animals it released growth hormone without the ACTH or cortisol release seen with GHRP-6, the reason it is called selective. In human volunteers growth hormone release was dose-dependent and short-lived. |
| Tesamorelin | GHRH receptor | Theratechnologies · TH9507 | Under an hour | Approved (US 2010, Egrifta) for excess abdominal fat in HIV-associated lipodystrophy | Visceral adipose tissue fell by about 15% over 26 weeks against a rise on placebo, held through 52 weeks of continued treatment and reversed on withdrawal. A later 12-month trial measured a reduction in liver fat. |
Trial figures are as reported in the papers cited on each product page, in the populations those trials enrolled. They are quoted as published research context, not as claims about any product sold on this site.
How each molecule is built
CJC-1295 with DAC
A 29-residue GHRH fragment with four substitutions that resist enzymatic cleavage, plus a Drug Affinity Complex: a reactive group on the C-terminus that bonds to serum albumin after administration. Riding on albumin is what turns a minutes-long peptide into a week-long one. The same fragment without the DAC group is sold elsewhere as "CJC-1295 no DAC" or modified GRF(1-29) and has a half-life of minutes; the two are not interchangeable in a study design.
Ipamorelin
A pentapeptide, Aib-His-D-2-Nal-D-Phe-Lys-NH2, built from the GHRP series with two D-amino acids and a non-natural naphthylalanine. It is a ghrelin receptor agonist, not a GHRH analogue, so it acts on the second of the two pathways above. Its short half-life is a property of the small peptide, not a defect.
Tesamorelin
Full-length GHRH(1-44) with a trans-3-hexenoyl group on the N-terminal tyrosine, which blocks DPP-4 without changing receptor binding. It is the one member of this class with a marketing approval, for one specific indication, and its clinical literature is correspondingly the deepest.
Related compounds you will see in the literature
- Sermorelin: GHRH(1-29) without modifications. Approved in the United States in 1997 for paediatric growth-hormone deficiency and withdrawn from the market in 2008 for commercial reasons.
- GHRP-2 and GHRP-6: the earlier ghrelin mimetics from which ipamorelin was derived; both also release cortisol and prolactin, which ipamorelin was designed to avoid.
- Ibutamoren (MK-677): an orally active non-peptide ghrelin mimetic. Not a peptide and not in our catalog.
Handling notes for this class
- All three are supplied as lyophilised powder and stored at −20°C in the dark.
- Tesamorelin's sequence contains methionine, which oxidises in solution; keep reconstituted material dark and use it promptly.
- CJC-1295 with DAC contains a reactive maleimide group; it should be reconstituted immediately before use rather than stored in solution.
- Concentration arithmetic is on the reconstitution calculator; storage horizons by form are on the storage guide.
In our catalog
CJC-1295 with DAC, Ipamorelin and Tesamorelin, each with its specifications, the references summarised above with PubMed links, and the certificate for the lot in stock where one exists.