COMMON QUESTIONS
Questions the Literature Can and Cannot Answer
Short answers, each traced to the study it came from - and an explicit refusal where the study does not exist.
What is ipamorelin?
Ipamorelin is a synthetic five-amino-acid peptide, sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2, that acts as a selective agonist at the ghrelin / growth hormone secretagogue receptor GHS-R1a on pituitary cells. It was derived from the earlier peptide GHRP-1 and also appears under the code NNC 26-0161. Its defining property, established in its founding characterization, is that it releases growth hormone potently while leaving ACTH and cortisol at the level GHRH itself produces, even at doses more than 200-fold above its growth-hormone ED50 [6]. It has no approved human indication in any country and is supplied as a research chemical.
What does ipamorelin do?
In the measured literature, ipamorelin produces a single discrete pulse of growth hormone. In healthy male volunteers given fifteen-minute intravenous infusions, the growth-hormone response peaked at about 0.67 hours - roughly 40 minutes - and the peptide itself had a terminal half-life of approximately two hours [4]. In adult female rats, fifteen days of subcutaneous administration raised the longitudinal bone growth rate from 42 to as much as 52 micrometers per day, with no measurable change in total IGF-1 or in bone turnover markers [5]. Beyond that pulse, no human outcome has been demonstrated: the only Phase 2 trial missed its primary endpoint [3].
Is ipamorelin FDA approved?
No. Ipamorelin has never been approved as a drug for any indication in any jurisdiction. It was investigated for postoperative ileus under NCT00672074 and that program did not succeed [3]. On the compounding side, the FDA removed ipamorelin acetate from Category 2 of the interim Section 503A bulk drug substances list in 2024 after the nominator withdrew, and reviewed the acetate and free base at the October 29, 2024 Pharmacy Compounding Advisory Committee meeting; it is not an approved bulk substance for compounding. It is also prohibited in sport at all times under WADA category S2.
What are the risks of ipamorelin?
The documented risks are mostly gaps rather than events. There is no Phase 3 trial and no long-term human safety database; the largest controlled human dataset is 114 participants dosed intravenously for at most seven days [3]. The most concrete adverse signal in the class comes from a different molecule: a 28-day preclinical study of the GHS-R1a agonist GSK894281 found dose-dependent myocardial degeneration and necrosis in rats, with elevated heart-type fatty-acid-binding protein and no troponin rise [2]. Mechanistically, raising growth hormone raises IGF-1, a mitogen, which is why active or recent malignancy is a standing caution across the class. Research-grade material from unregulated suppliers additionally carries no assurance of identity, purity or sterility.
What is CJC-1295 / ipamorelin good for?
In terms of demonstrated human outcomes, nothing has been established - because the combination has never been evaluated in a controlled clinical trial for any outcome. What can be said is component-level. A single subcutaneous dose of CJC-1295 with DAC raised mean plasma growth hormone two- to ten-fold for six days or more and IGF-1 1.5- to three-fold for nine to eleven days in healthy adults [10]. Co-activating the two receptors in transfected cells doubled the cyclic AMP response relative to GHRH-receptor activation alone [12]. Those are pharmacology results. The uses commonly attributed to the pairing - sleep, recovery, body composition - rest on community report and mechanism, not on a pre-specified endpoint.
What are the bad side effects of CJC-1295 and ipamorelin?
No controlled trial of the pairing exists, so there is no adverse-event table to quote. Two sources of information fill that space, and they should not be confused. The first is class pharmacology: a review of growth-hormone secretagogues identified increased blood glucose from decreased insulin sensitivity as the chief safety concern, and noted that long-term cancer-incidence and mortality data are still needed [9]. Growth-hormone excess is also classically associated with fluid retention, carpal-tunnel-type nerve compression and joint pain. The second is community self-report, which is anecdotal, not clinical evidence: injection-site reactions, transient puffiness, facial flushing, tingling in the hands, grogginess and light-headedness are commonly described, with no verified dose or source behind any of it.
How long do CJC-1295 and ipamorelin take to work?
The honest answer depends on what is meant by work, and only the hormonal question has measured data. On growth-hormone release the components act on very different clocks: ipamorelin's response peaks about 40 minutes after an intravenous dose and the peptide is cleared with a terminal half-life near two hours [4], whereas a single subcutaneous dose of CJC-1295 with DAC keeps growth hormone elevated for six days or more and IGF-1 elevated for nine to eleven days, with IGF-1 remaining above baseline up to 28 days after repeated dosing [10]. On any downstream outcome - body composition, recovery, sleep - there is no measured time course at all, because no trial of the combination has measured one.
How many mg of CJC-1295 and ipamorelin should I take?
This site does not answer that question, and no honest reading of the literature can. There is no approved dose for either compound, no dose-ranging study of the combination, and no published pharmacokinetic characterization of the subcutaneous route that most non-clinical use follows. The doses that do appear in the literature belong to specific studies and to specific routes: 0.03 mg/kg intravenously twice daily for up to seven days in ipamorelin's Phase 2 trial [3], and fifteen-minute intravenous infusions between 4.21 and 140.45 nmol/kg in its pharmacokinetic study [4]. Those figures describe what investigators administered under supervision in a defined protocol. They are not a schedule, and neither compound is approved for human use.
What is tesamorelin?
Tesamorelin is a synthetic 44-amino-acid analogue of human growth-hormone-releasing hormone, GHRH(1-44)-NH2, with a trans-3-hexenoic acid group on the N-terminus that blocks cleavage by dipeptidyl peptidase-IV and extends its stability in plasma. It is marketed as Egrifta and is the only compound in this hub with a regulatory approval: the FDA approved it in November 2010, under NDA 022505, to reduce excess abdominal fat in HIV-infected adults with antiretroviral-related lipodystrophy [13]. Outside that indication it has no approved human use, and it is prohibited in sport under WADA category S2.
What does tesamorelin do, and how does it work?
Tesamorelin binds the growth-hormone-releasing-hormone receptor on anterior-pituitary somatotrophs and activates the Gs / adenylyl-cyclase / cyclic-AMP / protein-kinase-A cascade, stimulating pulsatile secretion of the body's own growth hormone. That growth hormone drives hepatic IGF-1 production, and the pair promote lipolysis preferentially in visceral rather than subcutaneous fat. The effect is measurable in people: two weeks at 2 mg per day in thirteen healthy men raised mean overnight growth hormone by 0.5 micrograms per liter (P=0.004) and IGF-1 by 181 micrograms per liter (P<0.0001), while leaving fasting glucose (P=0.93) and insulin-stimulated glucose uptake (P=0.61) unchanged [15].
Will tesamorelin help me lose belly fat?
The trials measured a narrower thing than that phrasing suggests, in a narrower group of people. In HIV-associated lipodystrophy, tesamorelin reduced visceral adipose tissue - the deep fat around the organs, measured as a cross-sectional area on a scan - by a pooled mean difference of -27.71 cm2 across five randomized controlled trials, along with -4.28% hepatic fat fraction and +1.42 kg lean body mass [8]. A six-month trial found a -42 cm2 treatment effect on visceral fat and a net -2.9% reduction in hepatic lipid [14]. Three qualifications travel with those numbers: the participants were HIV-positive adults on antiretroviral therapy, the visceral fat reaccumulated once dosing stopped [16], and use outside that population is off-label and was not what the trials tested.
Which of these three has the strongest human evidence?
Tesamorelin, and not narrowly. It has five randomized controlled trials pooled in a meta-analysis [8], a six-month trial with two imaging endpoints [14], a 52-week trial in 410 randomized participants that also documented what happens after withdrawal [16], a mechanistic study in healthy volunteers [15] and a regulatory approval [13]. Ipamorelin has one Phase 2 trial that missed its primary endpoint [3] and one pharmacokinetic study [4]. The CJC-1295 and ipamorelin combination has no human trial of its own at all. Ranking by mechanism would order these three quite differently, which is the reason this desk ranks by study.