# Sermorelin: GHRH(1-29), Pulsatile GH, and the Body-Composition Record > Sermorelin is the 29-amino-acid GHRH fragment that tells the pituitary to release the body's own growth hormone. A cited digest of the mechanism, the body-composition findings, the half-life, and the limits of the adult data. A stencilled, cited reading of the published GHRH(1-29) record — the pulsatile-GH mechanism, the body-composition findings, the ~10-12 minute half-life, and the hard limits of the adult data. Numbers first. Attribution after. ## The short version Sermorelin is a lab-supplied research peptide — a short copy of a brain signal. Your hypothalamus makes a hormone called GHRH (the brain's own "make growth hormone" message). Sermorelin is the first 29 amino-acid building blocks of that message — the shortest piece that still works — so it acts as a secretagogue (something that tells a gland to release its hormone). It nudges the pituitary to send out the body's *own* growth hormone in natural bursts. Studies have measured faster growth in growth-hormone-deficient children, restored growth-hormone levels in older men, and — for the closely related drug-class analog tesamorelin — less belly fat. This page is a research digest, not medical advice, and gives no human dosing. ## Sermorelin peptide: GHRH(1-29) structure and class Sermorelin is sermorelin acetate, the amidated synthetic 29-amino-acid peptide that copies the amino-terminal 1-29 fragment of human growth hormone-releasing hormone (GHRH), a 44-residue hypothalamic hormone. That 1-29 segment is the shortest fragment that keeps full activity at the GHRH receptor — the rest of the native molecule can be removed without losing the signal [13]. The **sermorelin peptide** sits in a defined drug class: a growth hormone-releasing hormone analog, also called a pituitary growth hormone secretagogue (a molecule that prompts a gland to release its own hormone). It is distinct from the growth hormone-releasing peptides (GHRPs) such as ipamorelin, which act on a different receptor — see [how sermorelin works](/research). Its molecular weight is 3357.9 Da and its CAS number is 86168-78-7. Regulatory history matters here and is often misstated. Sermorelin was a fully FDA-approved prescription product (NDA 020443) for evaluating and treating growth-hormone deficiency and short stature in children. It was withdrawn from the US market in 2008 for commercial reasons — not for safety or efficacy problems [5]. It is now prepared by compounding pharmacies and treated as a long-standing Category 1 bulk drug substance under FDA's Section 503A framework (final guidance January 2025). The correct frame is a *formerly FDA-approved* GHRH analog, now compounded — not "currently approved," and not "never approved." ## What does sermorelin do to the body? Sermorelin binds GHRH receptors on the somatotrophs (the growth-hormone-producing cells) of the anterior pituitary and stimulates the gland to synthesize and release the body's own growth hormone (GH) in its natural pulses. Downstream, GH drives the liver to produce IGF-1 (insulin-like growth factor 1 — a growth signal the liver makes when GH rises), the hormone that carries out many of GH's effects [13]. Because sermorelin acts *upstream* on the pituitary rather than supplying growth hormone directly, the body's feedback brakes stay intact: somatostatin and IGF-1 still throttle the system, so the pulsatile (released in natural bursts, not a steady drip) pattern of GH secretion is preserved. An editorial in *Clinical Interventions in Aging* argued that this preserved-feedback, physiologic design makes a secretagogue a more physiologic approach to adult growth-hormone insufficiency than supplying recombinant GH directly [4]. ## Sermorelin benefits reported in the research literature The clearest documented result is in children. In a multicenter trial of prepubertal growth-hormone-deficient children, once-daily subcutaneous GHRH(1-29) raised first-year height velocity from about 4.1 cm/year to roughly 7-8 cm/year, without excessive IGF-1 generation [1]. In older adults, twice-daily GHRH(1-29) reversed the age-related fall in GH and IGF-1: at the high dose (1 mg twice daily for 14 days), GH and IGF-1 in men averaging 68 years no longer differed from those of young men, with no change in fasting glucose [2]. Body-composition and cognition signals come mainly from the stabilized drug-class analog tesamorelin, which is studied alongside GHRH(1-29). A randomized, double-blind, placebo-controlled trial of 152 older adults found a favorable effect on cognition (P=0.03), raised IGF-1 by 117% within the physiologic range, and reduced percent body fat by 7.4% [6]. These are GHRH-axis findings — reported here factually, not as a proven anti-aging benefit of sermorelin specifically. ## Sermorelin and weight loss: what the body-composition studies show Direct weight-loss trials of GHRH(1-29) itself are limited. The body-composition evidence in this drug class comes from the stabilized GHRH analog tesamorelin. In HIV-infected patients with abdominal fat accumulation, tesamorelin significantly reduced visceral adipose tissue versus placebo — demonstrating that GHRH-axis stimulation can produce measurable changes in body composition [9]. A separate randomized trial of GHRH in HIV-infected men with lipodystrophy evaluated the same axis on fat distribution [10]. Mechanistically, the GH/IGF-1 axis and abdominal fat are linked: in 47 men studied under combined GHRH and GHRP-2 infusion, abdominal visceral fat, IGF-1 and IGFBP-3 together explained 60% of the variability in the GH response, with visceral fat negatively associated [7]. The honest framing: **sermorelin weight loss** marketing outpaces the sermorelin-specific evidence. The drug-class fat-loss data are real and cited; a proven anti-aging or general-population weight-loss benefit for GHRH(1-29) is not established. ## Sermorelin before and after: outcomes reported in studies When people search **sermorelin before and after**, they usually want measured outcomes rather than anecdotes. The literature reports several, each tied to its study. In growth-hormone-deficient children: first-year height velocity rose from about 4.1 to roughly 7-8 cm/year on once-daily subcutaneous GHRH(1-29) [1]. In short children with *normal* GH secretion, evening GRF(1-29)NH2 at 5 micrograms/kg for six months increased growth velocity even though 24-hour GH profiles did not change significantly [8]. In older men: GH and IGF-1 measures, depressed by age, returned to the young-adult range after high-dose GHRH(1-29) [2]. In the drug-class cognition trial: IGF-1 +117% within the physiologic range and percent body fat -7.4% over 20 weeks [6]. The [body-composition findings](/research) are reported as measured study endpoints, not testimonials. ## Does sermorelin burn fat? Sermorelin itself is studied for its GH and IGF-1 effects; the clearest fat-loss evidence in this drug class comes from the stabilized GHRH analog tesamorelin, which significantly reduced visceral adipose tissue versus placebo in HIV-related fat accumulation [9]. That is GHRH-axis evidence, reported factually — not a demonstrated fat-burning effect of sermorelin in the general population. ## Is sermorelin effective for weight loss? Direct weight-loss trials of GHRH(1-29) are limited. GHRH-axis stimulation reduced percent body fat by 7.4% in a cognition trial using the analog tesamorelin [6], but anti-aging and weight-loss marketing outpaces the evidence for sermorelin specifically. The literature supports measured body-composition change in the drug class, not a proven general weight-loss indication. ## Does sermorelin build muscle? Sermorelin raises GH and IGF-1 — the anabolic axis [2]. A men's-health review discusses GH/IGF-1 modulation by secretagogues as a candidate strategy within body-composition management [11], but rigorous lean-mass trials of sermorelin in healthy adults are scarce. The honest statement is a plausible mechanism with thin direct outcome data. ## Sermorelin before and after: what changes do studies report? Measured outcomes in the literature include first-year height velocity rising from about 4.1 to 7-8 cm/year in GH-deficient children [1], restored GH and IGF-1 in older men at the high dose [2], and IGF-1 and body-fat changes in GHRH-analog trials [6]. These are study endpoints across distinct populations, not before-and-after photos. ## What is sermorelin? Sermorelin is sermorelin acetate — the amidated synthetic 29-amino-acid N-terminal fragment of GHRH, written GHRH(1-29), and the shortest fragment that retains full activity at the GHRH receptor [13]. It is a pituitary growth-hormone secretagogue, formerly FDA-approved for pediatric growth-hormone deficiency and now compounded. ## What is sermorelin used for? Sermorelin was FDA-approved to evaluate and treat growth-hormone deficiency and short stature in children, where it accelerated linear growth [1]. In adult research it has been studied for the age-related decline in GH and IGF-1 [2] and related endpoints. Adult anti-aging and body-composition uses are studied but not established. --- The GHRH(1-29) record stencilled onto raw concrete — the pulsatile-GH mechanism, the studied doses, the body-composition data filed where it belongs as tesamorelin, the formerly-approved-then-withdrawn history set straight, and the thin adult-safety line sprayed in caution-orange; no clinic behind the wall and nothing here dosed, compounded, or sold.