# Sermorelin FAQ: GHRH(1-29) Questions Answered from the Research > Sermorelin questions answered from the published literature: what it is, what it does, whether it works, how it compares to ipamorelin, CJC-1295, and tesamorelin, side effects, IGF-1, sleep, and timing. Cited, no advice. Direct, cited answers to the most-asked GHRH(1-29) questions — definitional, comparative, mechanistic, and safety. Research context only; no dosing instructions. ## What is sermorelin? Sermorelin (GHRH(1-29)NH2 / GRF(1-29)) is a synthetic 29-amino-acid analog of growth hormone-releasing hormone — a pituitary GH secretagogue [1]. It was formerly FDA-approved for growth hormone deficiency in children, withdrawn from the US market in 2008 for commercial reasons, and is now prepared by compounding pharmacies as a Category 1 503A bulk substance. ## What does sermorelin do to the body? It binds GHRH receptors on pituitary somatotrophs and activates the cAMP/PKA pathway, stimulating the body's own pulsatile growth hormone release [1]. The higher GH then raises hepatic IGF-1. Because it works upstream through the body's own gland, natural feedback through somatostatin and IGF-1 stays intact. ## Does sermorelin work? In GH-deficient children it accelerated first-year height velocity from about 4.1 to 7-8 cm/year [1]; in older men it raised 24-hour GH and IGF-1 at the high dose [2]. Long-term adult anti-aging efficacy data remain limited, and authorities have urged caution about that use [5]. ## How long does it take for sermorelin to work? Acutely, a single dose elevates serum GH for roughly 3 hours despite a 10-12 minute plasma half-life [3]. Trial outcomes such as IGF-1 changes were measured over longer windows — 14 days in the older-men study [2] and 20 weeks in the cognition trial of a related analog [6]. ## What is sermorelin used for? Its historical FDA-approved indication was idiopathic GH deficiency / short stature in children [1]. Research has also examined the GH/IGF-1 axis in aging, cognition, sleep, and body composition, largely through GHRH(1-29) and its stabilized analogs [2][6]. This site documents that research; it is not a use recommendation. ## How does sermorelin compare to CJC-1295? Sermorelin is native GHRH(1-29) with a short half-life; CJC-1295 is a long-acting GHRH analog (DAC technology) that produced prolonged GH and IGF-1 elevation over days in healthy adults [10]. Same receptor, very different duration of action. ## Sermorelin vs ipamorelin: what is the difference? Sermorelin is a GHRH-receptor analog; ipamorelin is a selective GH secretagogue acting on the ghrelin/GHS receptor, characterized as releasing GH without significant ACTH/cortisol or prolactin effects [9] — a different mechanism reaching the same pituitary cells. ## How does sermorelin differ from direct HGH injections? Sermorelin acts upstream on the pituitary to stimulate the body's own pulsatile GH release with feedback intact; direct HGH supplies the hormone from outside. An editorial argues the secretagogue route is a more physiologic approach to adult GH insufficiency than recombinant GH [4]. ## Sermorelin vs tesamorelin: how do they differ? Tesamorelin is a stabilized GHRH analog (FDA-approved for HIV-associated lipodystrophy only) studied at 2 mg/day for visceral fat and 1 mg/day for cognition [8][6]; sermorelin is the native GHRH(1-29) fragment, formerly approved for pediatric GH deficiency and now compounded. ## What pairs well with sermorelin (e.g., ipamorelin or GHRP-2)? Research-user communities describe pairing a GHRH analog with a GHRP-class secretagogue such as ipamorelin; the two classes act on different receptors [9]. This is a research-context observation about mechanism, not a dosing recommendation, and no protocol is given here. ## Does sermorelin affect testosterone? Sermorelin acts on the GH/IGF-1 axis, not directly on the gonadal axis [1]. The research literature documents GH and IGF-1 changes [2][3], not testosterone effects, so claims of a testosterone benefit are not supported by the GHRH(1-29) record and are framed here factually. ## Will sermorelin raise my IGF-1 levels? GHRH(1-29) raises GH and, downstream, IGF-1. In older men, high-dose GHRH(1-29) twice daily for 14 days restored IGF-1 toward young-adult levels [2]; in the SMART trial of a stabilized analog, IGF-1 rose by 117% within the physiologic range [6]. ## Does sermorelin burn fat? The GHRH analog tesamorelin reduced visceral fat in clinical trials, and the SMART trial reported a 7.4% reduction in percent body fat [6]; pulsatile GH contributes to lipolysis. That said, anti-aging and body-composition marketing outpaces the evidence for sermorelin itself [5]. ## Is sermorelin effective for weight loss? Body-composition effects are documented mainly for the related analog tesamorelin (visceral fat, body-fat percentage) [6], not as approved weight-loss outcomes for sermorelin. Rigorous long-term efficacy data for that use are limited, and authorities have cautioned against assuming the benefit [5]. ## Does sermorelin build muscle? By raising GH and IGF-1, GHRH-axis stimulation is studied in the context of body composition and sarcopenia, but direct muscle-growth efficacy for sermorelin in adults is not established [5]. The findings here are described, not recommended, and no dosing is provided. ## Does sermorelin affect the brain? A randomized trial found a favorable cognitive effect from 20 weeks of a daily GHRH analog in older adults (P=0.03), strongest in executive function [6], and related work has examined GHRH effects on brain chemistry. Sermorelin and GHRH analogs are studied for neuroendocrine effects. ## Can sermorelin or GHRH improve cognition in older adults? A randomized, double-blind, placebo-controlled trial of 152 older adults found 20 weeks of a daily GHRH analog had a favorable effect on cognition (P=0.03), with the strongest signal in executive function (P=0.005) [6]. The result is for tesamorelin, a stabilized GHRH analog, not sermorelin specifically. ## What are the side effects of sermorelin? Reported effects in trials were generally mild — injection-site reactions, and no fasting-glucose change in the older-men study [2]. Long-term adult-use safety data are limited [5], and because GH/IGF-1 are mitogenic, a theoretical oncologic consideration is noted for any GH-axis intervention. ## Does sermorelin actually help with sleep, or is it waking me up instead? GHRH itself has slow-wave-sleep-promoting effects in research, and the sleep-endocrine response depends on when it is given relative to the natural nocturnal GH rhythm [12]. Individual experiences in user reports vary; this is framed as research context, not advice or a protocol. ## Why is it recommended to inject sermorelin at night? Endogenous GH is secreted in pulses, especially during slow-wave sleep, so research protocols administered GHRH analogs before bedtime to align with the natural nocturnal rhythm — the SMART trial dosed 1 mg/day before sleep [6]. Stated as study design, not a usage recommendation. ## When is the best time to take sermorelin? Research protocols dosed GHRH analogs before bedtime to coincide with nocturnal pulsatile GH release [6][12]. This reflects study design rather than a usage recommendation, and no human dosing instructions are provided on this site. ## Is 3 months of sermorelin enough? Study durations varied widely — from 14-day GH/IGF-1 pharmacology work [2] to 20-week cognition trials [6] and year-long pediatric growth studies [1]. The literature does not define an adult "enough" duration; this is offered as study context only. --- A confidence-graded intelligence brief on the GHRH(1-29) secretagogue record — each figure scored against its study, the pediatric-growth evidence held apart from the limited adult anti-aging data and the formerly-approved-now-compounded status stated plainly; no clinic behind the console and nothing here dosed, prescribed, or sold.