Tesamorelin vs CJC-1295: Same Receptor, Different Clock

Tesamorelin and CJC-1295 act on the same receptor. Both are analogues of growth hormone-releasing hormone (GHRH), both bind the GHRH receptor on the pituitary, and both raise growth hormone and IGF-1. What separates them is how long they last, which "CJC-1295" is meant — and the fact that only one of them was ever approved.

They were even developed towards the same clinical target. Tesamorelin was approved for excess abdominal fat in HIV-associated lipodystrophy; CJC-1295 entered a phase 2 trial in HIV patients with visceral obesity that was terminated without results. This covers how the molecules differ, what that means for the evidence, and what cannot be concluded from it.

What each one is

• Tesamorelin is the full 44-residue GRF(1-44) sequence with a trans-3-hexenoic acid group on the N-terminus. The modification protects it from dipeptidyl peptidase-4 cleavage and extends its half-life, though only to minutes: it is still a once-daily injection. Developed as TH9507, it was approved by the FDA in November 2010 (Spooner and Olin 2012). See the tesamorelin profile.

• CJC-1295 with DAC is a shorter GRF(1-29) analogue with four amino-acid substitutions that resist enzymatic breakdown, plus a reactive group that bonds covalently to circulating albumin after injection. That albumin depot is the Drug Affinity Complex, and it stretches the half-life from minutes to days. See the CJC-1295 profile.

• CJC-1295 without DAC, also sold as Mod GRF(1-29), has the same four substitutions but no albumin-binding group. It is short-acting and pharmacologically distinct from the DAC form despite the shared name. See the no-DAC profile.

All three sit in the same family as sermorelin, which is GHRH(1-29) itself. The differences are engineering choices about how to keep a fragile hormone intact long enough to work.

Same receptor, different clock

At the receptor, the three do the same thing: bind the pituitary GHRH receptor, raise cyclic AMP, and stimulate growth hormone synthesis and release, with IGF-1 rising downstream. Release stays subject to somatostatin and IGF-1 feedback. The difference is timing.

Tesamorelin has a half-life of 26–38 minutes. Each injection is a transient stimulus, and the approved product is injected once daily.

CJC-1295 with DAC had an estimated half-life of 5.8–8.1 days in healthy adults. After a single subcutaneous injection, mean growth hormone rose two- to ten-fold for six days or more and IGF-1 rose 1.5- to three-fold for nine to eleven days; after repeated doses, IGF-1 stayed above baseline for up to 28 days (Teichman 2006). A second study found that growth hormone pulses persisted under this continuous stimulation — pulse frequency and size were unchanged — but trough levels rose about 7.5-fold, and that raised baseline accounted for much of the increase in mean growth hormone and IGF-1 (Ionescu and Frohman 2006).

CJC-1295 without DAC is short-acting, on the order of thirty minutes, producing a brief pulse more like tesamorelin's than like the DAC form's. No human pharmacokinetic study of this specific molecule is indexed, so that figure is not a measured human value.

The practical upshot: tesamorelin and no-DAC CJC-1295 are pulse generators; CJC-1295 with DAC is closer to a continuous stimulus with pulses riding on top of it.

Side by side

The CJC-1295 name problem

"CJC-1295" on a vial can mean either molecule, and the difference is not a detail. A half-life of about thirty minutes and one of about a week imply entirely different exposure from the same labelled amount.

The confusion also runs through the evidence. Both published human dosing studies used the DAC form. Pages selling the no-DAC version routinely cite them anyway, and that transfer does not hold: human data for the DAC form is not evidence for a molecule without it. The closest human data for the no-DAC form is on its parent, GHRH(1-29), given intravenously or intranasally in a 1993 study (Wilton 1993) — a related but distinct analogue.

What the human evidence looks like

Tesamorelin has a regulatory-grade programme. Two randomised, placebo-controlled phase 3 trials in people with HIV-associated central fat accumulation showed reduced visceral adipose tissue and waist circumference over 26 weeks, maintained to week 52 on treatment, with visceral fat returning after discontinuation (Dhillon 2011; Spooner and Olin 2012). The phase 3 trial registered as NCT00123253 enrolled 412 patients on 2 mg daily of the original formulation; the Egrifta SV label specifies 1.4 mg by subcutaneous injection once daily for the approved indication. The label warns that tesamorelin raises IGF-1, which should be monitored, and can cause glucose intolerance or diabetes.

CJC-1295 with DAC has two small pharmacology studies in healthy adults (Teichman 2006; Ionescu and Frohman 2006) and a follow-up analysis of serum proteins before and after injection in 11 men (Sackmann-Sala 2009). The first of those reported no serious adverse reactions. Its one registered efficacy trial — phase 2, in HIV patients with visceral obesity (NCT00267527) — was terminated and posted no results. That is the gap in one sentence: the two compounds were aimed at the same condition, and only one produced outcome data.

CJC-1295 without DAC has no registered trial and no indexed human study of its own.

A 2026 review of GH-axis peptides sold as research compounds lists all three as GHRH analogues and contrasts the published evidence with the self-administration protocols circulating online (Dominikowski 2026).

Why they get compared

People looking at GHRH analogues often see tesamorelin as "the approved one" and CJC-1295 as the longer-acting alternative. They do share a receptor. That does not make one a substitute for the other. Tesamorelin's outcome data comes from a specific population and a daily, pulsatile regimen. CJC-1295 with DAC produces a different exposure pattern and has no outcome data at all. For the other common comparison in this class, see tesamorelin vs sermorelin.

Side effects and safety signals

Tesamorelin's adverse effects come from controlled trials. Serious treatment-emergent events occurred in under 4% of patients over 26 weeks, and most were injection-site reactions or effects known from growth hormone therapy, such as joint pain, headache and peripheral oedema (Dhillon 2011).

For CJC-1295 with DAC, the 2006 study authors described it as safe and relatively well tolerated, particularly at the lower doses tested (Teichman 2006). Small, short studies in healthy volunteers are not a safety profile, though. The IGF-1 warning on the tesamorelin label is a reasonable question to ask of any GHRH analogue that holds IGF-1 above baseline for weeks — an inference from shared mechanism, not a finding. For the no-DAC form there is no human safety data at all.

What the evidence does not show

• Which is more effective. No trial has compared tesamorelin and CJC-1295 directly.

• That CJC-1295 reduces visceral fat. Its only trial for that purpose was terminated without results.

• That tesamorelin's effect generalises. Every phase 3 result is from HIV-associated lipodystrophy.

• That sustained elevation is equivalent to daily pulses. The DAC form raises trough growth hormone; whether that matters for outcomes, good or bad, is untested.

• Long-term safety of CJC-1295. The human exposure data covers weeks, in small numbers of healthy volunteers.

Vial math and handling

Both are lyophilised powders reconstituted before use. The tesamorelin calculator and the CJC-1295 + ipamorelin calculator turn a vial size and diluent volume into a concentration and a syringe reading, and the insulin syringe units converter handles the unit markings. They answer what a draw contains, not what quantity is appropriate. The approved tesamorelin product comes with its own diluent and instructions, which take precedence. The reconstitution guide and storage guide cover the rest.

Frequently asked questions

Is CJC-1295 the same as tesamorelin?

No. Both are GHRH analogues acting on the same receptor, but they are different molecules: tesamorelin is a modified GRF(1-44), CJC-1295 a modified GRF(1-29). Tesamorelin is FDA-approved for one indication; CJC-1295 is not approved for anything.

Which is stronger, tesamorelin or CJC-1295?

There is no head-to-head data to answer that. The DAC form raises growth hormone and IGF-1 for longer after a single injection, but duration is not strength, and neither CJC-1295 form has outcome data to compare with tesamorelin's.

Tesamorelin vs CJC-1295 for fat loss?

Tesamorelin reduced visceral fat in randomised trials in people with HIV-associated lipodystrophy. CJC-1295's trial in the same kind of population was terminated without results. Beyond that population, neither has human fat-loss evidence. See peptides for weight loss for compounds with broader trial data.

Can tesamorelin and CJC-1295 be taken together?

No study has examined it. Both act on the GHRH receptor, so the pairing lacks the two-receptor rationale behind combining a GHRH analogue with a ghrelin-receptor agonist such as ipamorelin. Combinations with stated evidence grades are in the peptide stacks directory.

Is CJC-1295 FDA approved?

No. Neither the DAC nor the no-DAC form is approved, and both are prohibited in sport under WADA class S2 — as is tesamorelin, despite its approval.