FAQ
Common Questions, Straight Answers
Plain-language answers to the most-asked questions about GH axis research peptides — with citations where the research is firm, and honest uncertainty where it is not.
What is ipamorelin?
Ipamorelin (NNC 26-0161) is a synthetic five-amino-acid peptide that selectively activates the ghrelin receptor (GHS-R1a) on the anterior pituitary to trigger a pulse of growth hormone release [6]. Its defining feature is selectivity: it stimulates GH potently without significantly raising cortisol or prolactin — a contrast with earlier GH-releasing peptides. It is a research chemical, not an approved drug.
What does ipamorelin do for you?
In animal studies, ipamorelin stimulates GH release and, in rats, increased longitudinal bone growth rate dose-dependently [5]. Its only published Phase 2 human trial, in postoperative bowel resection patients, missed its primary endpoint [3]. Community accounts describe improved sleep, faster recovery, and gradual body composition changes — but these are anecdotal, not clinical findings. There are no controlled human trials confirming efficacy for any wellness or body-composition use.
What is ipamorelin peptide?
A peptide is a short chain of amino acids. Ipamorelin is a pentapeptide — five amino acids — with the sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2. The unusual amino acids (alpha-aminoisobutyric acid, D-2-naphthylalanine, D-phenylalanine) were chosen to confer protease resistance and GHS-R1a selectivity. It is synthesized, not extracted from a biological source. It is not an approved drug in any country.
What are the risks of ipamorelin?
Known and theoretical risks include: (1) a class-level cardiovascular signal — a related GHS-R1a agonist caused myocardial damage in a 28-day rat study [2]; (2) theoretical cancer risk from GH-axis stimulation and downstream IGF-1 elevation; (3) potential glucose disruption, including direct pancreatic beta-cell effects [6]; (4) increased appetite via GHS-R1a; (5) unknown long-term human safety — the only human datasets are a 7-day IV trial [3] and a single-dose PK study [4]. Research-grade material is of unverified purity.
What is CJC-1295?
CJC-1295 is a synthetic analog of GHRH built on the first 29 amino acids of human growth-hormone-releasing factor, with four protease-stabilizing substitutions and, in its DAC (Drug Affinity Complex) form, a chemical arm that binds to albumin to extend its half-life to approximately 5.8–8.1 days [11]. The no-DAC form (Modified GRF 1-29) has the same stabilizing substitutions but lacks albumin binding and is short-acting. CJC-1295 is not an approved drug and is prohibited in sport.
What does CJC-1295 do?
In early human pharmacology studies, CJC-1295 produced dose-dependent, sustained elevation of GH and IGF-1: mean GH rose 2- to 10-fold for 6 days or more from a single injection; IGF-1 rose 1.5- to 3-fold for 9–11 days [11]. Natural pulsatility of GH secretion was preserved [12]. These are PK/PD results in small, short studies of healthy adults — not evidence of clinical benefit for any wellness endpoint.
Is CJC-1295 safe?
Long-term safety in humans is unknown. Published human data come from small, short pharmacokinetics studies [11][12]. The development program was halted and the compound was not approved. The FDA has cited immunogenicity concerns for this class [8]. Mechanistic cautions include sustained IGF-1 elevation (a theoretical cancer-risk concern), fluid retention, insulin-sensitivity effects, and the risk that the DAC and no-DAC forms — with very different durations — are confused. It is not possible to characterize CJC-1295 as safe for human use.
How much CJC-1295 should I take?
This desk does not provide human dosing recommendations for any compound. CJC-1295 has no approved human indication. The doses used in published pharmacokinetics studies were research doses in controlled settings — not dosing guidance for self-administration. Circulating community protocols have no controlled-trial basis, and the DAC and no-DAC forms differ so substantially in duration that treating them as dose-equivalent is an error.
What is sermorelin?
Sermorelin is the 1-to-29 amino-terminal fragment of human growth-hormone-releasing hormone — the shortest GHRH fragment that retains full activity at the GHRH receptor. It was formerly FDA-approved for pediatric GH deficiency (NDA 020443) and was withdrawn from the US market in 2008 for commercial, not safety, reasons [16]. It is now available through compounding pharmacies as a Category 1 bulk drug substance under FDA's interim 503A policy.
What does sermorelin do to the body?
Sermorelin binds GHRH receptors on the anterior pituitary and triggers pulsatile GH release. In pediatric GH-deficient children, once-daily subcutaneous dosing accelerated linear growth velocity from approximately 4.1 cm/year to 7–8 cm/year in the first year [16]. In an RCT of older adults, a GHRH analog improved executive cognition, raised IGF-1 by 117%, and reduced body fat by 7.4% [13]. Sermorelin preserves pituitary feedback, so the GH response is self-limiting — a mechanistic advantage over exogenous GH [15].
Does sermorelin work?
For its original approved indication — pediatric GH deficiency — yes: multicenter clinical trials showed meaningful acceleration of linear growth [16]. For the wellness, anti-aging, and body-composition uses it is currently marketed for, the evidence is insufficient. A 2008 Annals of Internal Medicine editorial explicitly concluded that GH-secretagogue use to prevent or treat aging is "not yet ready for prime time" [14]. Community reports of improved sleep and gradual fat loss are anecdotal — not clinical evidence.
How long does it take for sermorelin to work?
Community accounts consistently describe sermorelin as a slow-acting compound. Improved sleep is often reported within the first one to three weeks. Body-fat and composition changes, when reported, typically appear after two to three months of consistent use. These timelines are anecdotal patterns, not clinical measurements. In the approved pediatric indication, clinically meaningful height-velocity gains were documented at one year [16].
What is tesamorelin?
Tesamorelin is a synthetic 44-amino-acid analog of human GHRH with an N-terminal trans-3-hexenoic acid modification that resists enzymatic degradation. It is the only FDA-approved GHRH analog (NDA 022505, approved 2010) and the only compound on this desk with an approved drug indication — specifically, reducing excess abdominal fat in adults with HIV-associated lipodystrophy [18]. Outside that indication, it has no approved human use.
What does tesamorelin do?
Tesamorelin stimulates pulsatile GH secretion via the GHRH receptor and, downstream, raises IGF-1. In HIV-positive adults with lipodystrophy, it significantly reduced visceral adipose tissue, trunk fat, and hepatic fat, and increased lean mass — all confirmed across multiple randomized controlled trials and meta-analyzed in 2026 [17]. In healthy men, it raised GH and IGF-1 substantially without significantly affecting insulin sensitivity at 2 weeks [20].
How does tesamorelin work?
It binds the GHRH receptor on anterior-pituitary somatotrophs, activating adenylyl cyclase/cAMP signaling to stimulate endogenous GH release. Downstream GH then drives hepatic IGF-1 production and promotes lipolysis preferentially in visceral adipose tissue. Because it amplifies the body's own pulsatile GH rhythm rather than supplying exogenous GH, pituitary feedback through somatostatin and IGF-1 remains intact — a mechanistic feature it shares with sermorelin and CJC-1295 [17].
Will tesamorelin help me lose belly fat?
In the specific population studied — HIV-positive adults with antiretroviral-related lipodystrophy — yes: visceral fat reductions of 18–42 cm2 versus placebo have been documented in rigorous RCTs [17][19][21]. Whether these findings transfer to people without HIV who want to reduce visceral fat is plausible mechanistically but has not been established in large, well-controlled trials. An important caveat: visceral fat reaccumulates when tesamorelin is stopped [21]. This desk does not recommend its use for any purpose.