CJC-1295 vs Tesamorelin vs Ipamorelin vs Sermorelin
Three of these four target the same GHRH receptor at different levels of engineering; the fourth doesn't touch it at all. Here's how the mechanisms, regulatory status, and trial data compare across all four.
KYIN Peptides supplies CJC-1295, Tesamorelin, and Ipamorelin for laboratory research use. Sermorelin is not part of our standard catalogue but is available to order — see availability below.
At a Glance
| CJC-1295 | Tesamorelin | Ipamorelin | Sermorelin | |
|---|---|---|---|---|
| Molecular class | Modified, long-acting GHRH analog | Modified GHRH(1-44) analog | Selective ghrelin-receptor (GHSR1a) agonist | Unmodified GHRH(1-29) fragment |
| Receptor target | GHRH receptor | GHRH receptor | Ghrelin receptor (GHSR1a) | GHRH receptor |
| Duration of action | Extended — IGF-1 elevated up to 28 days with repeat dosing | Shorter, daily-dosed in its approved regimen | Not established to the same evidence standard | Cleared from circulation quickly — the reason later analogs were engineered for longer half-life |
| Regulatory status | Not FDA-approved; research use only | FDA-approved (Egrifta, 2010) | Not FDA-approved; research use only | Formerly FDA-approved (Geref); discontinued 2008 |
| Available from KYIN Peptides | Yes | Yes | Yes | No — available to order |
How the Mechanisms Differ
Three of these four compounds are variations on the same signal. Sermorelin is the unmodified GHRH(1-29) fragment — it retains full native bioactivity but is cleared from circulation quickly. CJC-1295 and Tesamorelin are both structurally modified descendants of that same GHRH signal, engineered specifically to resist rapid degradation and extend duration of action; Tesamorelin's stabilization work in particular carries a distinct research focus on lipid metabolism and visceral fat, distinguishing it from CJC-1295's more general long-acting GHRH signal.
Ipamorelin stands apart from all three: it doesn't act on the GHRH receptor at all, instead selectively activating the ghrelin receptor (GHSR1a) — a different receptor on the same growth-hormone axis. Because GHRH analogs and ghrelin secretagogues act on complementary points of the axis, they're often studied together rather than as substitutes for one another, which is precisely why KYIN pairs CJC-1295 with Ipamorelin in a single blend rather than offering it alongside Tesamorelin or Sermorelin.
Clinical Trial Data
CJC-1295: A human trial (Teichman et al., 2006; 65 healthy adult subjects) found that a single injection produced a dose-dependent GH increase of 2–10× baseline sustained for at least 6 days, and an IGF-1 increase of 1.5–3× baseline sustained for 9–11 days, consistent with an estimated half-life of 5.8–8.1 days. With repeated dosing, mean IGF-1 remained above baseline for up to 28 days, and the compound was well tolerated with no serious adverse events reported.
Tesamorelin: A Phase 3 randomized controlled trial (Falutz et al., New England Journal of Medicine, 2007; 412 HIV-infected adults with abdominal lipodystrophy) found that tesamorelin 2mg/day reduced visceral adipose tissue by 15.2% over 26 weeks, versus a 5.0% increase in the placebo group. A pooled analysis of two Phase 3 trials (806 participants total) confirmed a consistent 15–18% VAT reduction alongside triglyceride improvement. Based on this data, the FDA approved tesamorelin in November 2010 as Egrifta for VAT reduction in HIV-associated lipodystrophy — the only FDA-approved drug for this specific indication.
Ipamorelin: The foundational pharmacology paper (Raun et al., European Journal of Endocrinology, 1998) characterized ipamorelin's activity in rat pituitary cells and pigs, not in a human trial — establishing its selectivity (no significant ACTH or cortisol elevation, unlike earlier ghrelin-receptor agonists) but not efficacy or safety in humans. No completed human clinical trial of ipamorelin has been located.
Sermorelin: Unlike the other three, sermorelin has a completed pediatric approval history. The pivotal trials supporting its FDA approval (as Geref, in a 110-patient trial of prepubertal children with idiopathic GH deficiency) found daily subcutaneous sermorelin increased height velocity from a baseline of 4.1 cm/year to 8.0 cm/year, sustained through 36 months of continuous therapy; 74% of treated children showed increased growth velocity after 6 months. Geref was FDA-approved in 1990 (with a further approval in 1997) and later discontinued from the market in 2008 — a 2013 FDA determination confirmed the withdrawal was for commercial reasons, not safety or effectiveness.
CJC-1295 vs Tesamorelin vs Ipamorelin vs Sermorelin questions
Why compare CJC-1295, Tesamorelin, Ipamorelin, and Sermorelin together?
They're the four growth-hormone-axis compounds referenced across KYIN's GHRH & Growth Hormone research, spanning two different receptor mechanisms (GHRH receptor vs. ghrelin receptor) and very different levels of regulatory and clinical maturity, from a discontinued former FDA-approved drug to compounds with no completed human trial.
Which of these has FDA-approved trial data?
Only Tesamorelin (as Egrifta) is currently FDA-approved. Sermorelin was formerly FDA-approved (as Geref) but was discontinued from the market in 2008 for commercial reasons, not safety or effectiveness. CJC-1295 and Ipamorelin are not FDA-approved and remain research compounds.
How is Ipamorelin mechanistically different from the other three?
Ipamorelin acts on the ghrelin receptor (GHSR1a), not the GHRH receptor that CJC-1295, Tesamorelin, and Sermorelin all target. That's why it's frequently paired with a GHRH analog — as in KYIN's CJC-1295 + Ipamorelin Blend — rather than positioned as a direct substitute for any of the other three.
Does KYIN Peptides sell all four?
KYIN sells CJC-1295 (as part of the CJC-1295 + Ipamorelin Blend), Ipamorelin, and Tesamorelin. Sermorelin is not part of the standard catalogue but is available to order — contact us and we'll source it.
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