One problem, three solutions: natural growth hormone-releasing hormone (GHRH) is destroyed by enzymes within minutes, and ghrelin, the other GH trigger, is short-lived and hits several hormone systems at once. CJC-1295, tesamorelin and ipamorelin are three different engineering answers to those problems. This guide shows how each one was built, what the published human and animal data says, and how labs decide between them.
The two-minute problem
The pituitary releases growth hormone when GHRH binds its receptor. Native GHRH would be the obvious research tool, except that the enzyme dipeptidyl peptidase-4 (DPP-4) clips its first two amino acids almost immediately, inactivating it within minutes. Every GHRH analogue is a strategy for surviving that enzyme. Ipamorelin sidesteps the issue entirely by acting on a different receptor.
Side by side
| CJC-1295 (DAC) | Tesamorelin | Ipamorelin | |
|---|---|---|---|
| Receptor | GHRH receptor | GHRH receptor | Ghrelin receptor (GHS-R1a) |
| Built from | GHRH(1-29) + 4 substitutions + DAC | Full GHRH(1-44) + N-terminal hexenoyl group | Synthetic pentapeptide |
| Survival strategy | Albumin binding | Protected N-terminus | Different pathway |
| Duration | Days | Short | Short |
| Human data | Small 2006 studies | Randomized trials, approved product | Early clinical work |
| Signature finding | Prolonged GH/IGF-1, pulses preserved | Reduced visceral fat in specific trials | GH release without ACTH/cortisol rise |
CJC-1295: make it last for days
CJC-1295 keeps only the active first 29 amino acids of GHRH, swaps four of them to resist DPP-4 and other enzymes, and adds a Drug Affinity Complex that bonds to albumin in the blood. The result lasts days instead of minutes. Teichman and colleagues (2006) reported GH elevation for six days or more and IGF-1 elevation for 9 to 11 days after a single administration in healthy adults; Ionescu and Frohman (2006) showed the natural GH pulse pattern persisted. Watch the label: the version without DAC lasts about 30 minutes. See CJC-1295 with DAC.
Tesamorelin: keep the whole hormone, protect the front
Tesamorelin takes the opposite approach: it keeps the full 44-amino-acid sequence of human GHRH and adds a small chemical group at the very front, exactly where DPP-4 attacks. It remains short-acting, but it is the only compound in this group developed into an approved medicine in some jurisdictions. Randomized trials, beginning with Falutz and colleagues in 2007 (NEJM), reported reduced visceral abdominal fat in a specific patient population, which gives tesamorelin the strongest human dataset of the three. See Tesamorelin.
Ipamorelin: take the other road, cleanly
Ipamorelin does not touch the GHRH receptor at all. It activates the ghrelin receptor, the second switch for GH release. Older ghrelin-pathway compounds such as GHRP-6 and GHRP-2 also raised cortisol, ACTH and prolactin. Raun and colleagues (1998) described ipamorelin as the first selective GH secretagogue because, in their animal models, it released GH without significant increases in ACTH or cortisol. See Ipamorelin.
Because ipamorelin and the GHRH analogues work through different receptors, combining one of each produces a synergistic GH response in research models. That is the rationale behind the CJC-1295 + Ipamorelin blend, explained in depth in our Ipamorelin and CJC-1295 guide.
How labs choose
- Need a sustained, multi-day elevation of the GH axis? CJC-1295 with DAC.
- Need the compound with the most robust human clinical data, or a model close to native GHRH physiology? Tesamorelin.
- Need to isolate the ghrelin pathway, or avoid confounding cortisol effects? Ipamorelin.
- Studying dual-pathway synergy? A GHRH analogue plus ipamorelin.
| Product | Sizes | From |
|---|---|---|
| CJC-1295 with DAC | 2, 5, 10 mg | $31 |
| Tesamorelin | 2, 5, 10, 20 mg | $37 |
| Ipamorelin | 2, 5, 10 mg | $40 |
| CJC-1295 + Ipamorelin | 10 mg | $75 |
Frequently asked questions
Cliquez sur une question pour afficher la réponse.
What is the difference between CJC-1295 and tesamorelin?
Both act on the GHRH receptor. CJC-1295 with DAC is a modified 29-residue fragment that binds albumin and lasts days; tesamorelin is full-length GHRH with a protected N-terminus and a short duration, backed by randomized clinical trials.
Is ipamorelin a GHRH analogue?
No. Ipamorelin acts on the ghrelin receptor (GHS-R1a), a separate pathway that also triggers GH release.
Why do GHRH analogues break down so fast?
The enzyme DPP-4 removes the first two amino acids of native GHRH within minutes, inactivating it. Analogues are engineered to resist this.
Which has the most human data?
Tesamorelin, which went through randomized clinical trials and was approved for a specific indication in some jurisdictions.
Selected references
- Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295. J Clin Endocrinol Metab. 2006;91(3):799–805. PubMed
- Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295. J Clin Endocrinol Metab. 2006;91(12):4792–4797. PubMed
- Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552–561. PubMed
- Falutz J, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359–2370. NEJM
Related: What is tesamorelin?
All TrueLabs products are sold for in vitro and laboratory research use only. They are not intended for human or veterinary use, and nothing in this article is medical advice.