Readme.txt / FAQ
Sermorelin FAQ: common questions, answered from the record
Direct answers to the questions readers actually ask about sermorelin, each one returned to the published literature.
What is sermorelin used for?
In the research record it has two main contexts: a historical pediatric use — it was a prescription drug for growth hormone deficiency and short stature in children, since withdrawn from the US market — and adult GH-axis research, where GHRH(1-29) raised GH and IGF-1 in older men [2]. This digest reports those findings rather than recommending a use.
Why was sermorelin discontinued from the US market?
It was an FDA-approved prescription drug for pediatric growth hormone deficiency (NDA 020443) and was withdrawn from the US market in 2008 for commercial reasons, not because of safety or efficacy problems. It is now prepared by compounding pharmacies and treated as a Category 1 bulk drug substance under FDA's Section 503A framework.
Are there other peptides or applications being researched for GHRH analogs?
Recent reviews of GHRH and its analogues survey therapeutic applications of GHRH agonists and antagonists across health and disease [13], and situate GHRH within the broader central and peripheral control of the GH/IGF-1 axis [15]. The class is an active research area beyond sermorelin itself.
What is sermorelin?
Sermorelin (GHRH(1-29)NH2) is a synthetic 29-amino-acid peptide matching the first 29 residues of growth hormone-releasing hormone, the shortest fragment that keeps full activity at the GHRH receptor on pituitary cells [13]. As sermorelin acetate it has a molecular weight of 3357.9 Da. It is a GHRH analog, not growth hormone itself.
What does sermorelin do to the body?
It binds GHRH receptors on pituitary somatotrophs and prompts the body's own pulsatile release of growth hormone, which in turn raises liver-made IGF-1 [13]. Physiologic feedback through somatostatin and IGF-1 stays intact, so the natural burst pattern of GH secretion is preserved rather than overridden.
Does sermorelin work?
In controlled studies GHRH(1-29) produced measurable endocrine effects: in healthy older men, 0.5-1 mg twice daily for 14 days raised 24-hour GH and IGF-1, and at the high dose those values no longer differed from young men [2]. In GH-deficient children, daily dosing accelerated linear growth [1].
How long does it take for sermorelin to work?
Endocrine changes appear quickly in studies: a single dose elevated serum GH for roughly three hours [3], while measurable IGF-1 increases were reported over a 14-day course in older men [2]. Trial follow-up windows ranged from weeks to many months [1].
How does sermorelin compare to CJC-1295?
Both act on the GHRH receptor, but sermorelin is the short native GHRH(1-29) with a ~10-12 minute half-life [3]; CJC-1295 uses a DAC albumin-binding modification (building on a D-Ala2 substitution) to act far longer [3]. Same receptor target, very different duration.
Sermorelin vs ipamorelin: what is the difference?
They work through different receptors: sermorelin is a GHRH analog acting on the GHRH receptor, while ipamorelin is a growth hormone-releasing peptide (GHRP) acting on the ghrelin/GHS receptor [13]. Both prompt the pituitary to release its own GH, but through distinct pathways.
Does sermorelin actually help with sleep, or is it waking me up instead?
GHRH has a recognized physiologic role in slow-wave sleep, and growth hormone is secreted in pulses especially during deep sleep [1]. The reviewed evidence here is mechanistic rather than a controlled sleep-outcome trial, so individual sleep responses are not something this research digest can predict.
Why is it recommended to inject sermorelin at night?
Growth hormone is released mostly in pulses during slow-wave sleep, so bedtime timing aligns the stimulus with the body's natural nocturnal GH pulse; the pediatric efficacy trial dosed subcutaneously at bedtime [1]. This digest reports that study timing rather than recommending a schedule.
Does sermorelin burn fat?
Anti-aging and fat-loss marketing outpaces the evidence for sermorelin itself [5]. The clearest body-composition data in this class come from the related stabilized GHRH analog tesamorelin, which reduced body fat in trials [6]; pulsatile GH is also linked to lipolysis. For sermorelin specifically, this is not established.
Is sermorelin effective for weight loss?
No reviewed study tests sermorelin as a weight-loss treatment. Body-composition findings in the GHRH class come mainly from tesamorelin (visceral-fat reduction) [6]; for sermorelin specifically, weight-loss benefit is not established [5].
Does sermorelin affect testosterone?
Sermorelin acts on the GH/IGF-1 axis, not the testosterone axis, so it is not a testosterone therapy. One acute pediatric study did note small short-term rises in LH and FSH [8], but these were minor off-target effects, not a sustained testosterone action.
Will sermorelin raise my IGF-1 levels?
In studies it can: by increasing the body's own GH output, GHRH(1-29) raised IGF-1 in healthy older men over 14 days [2], and a stabilized GHRH-analog trial reported a 117% IGF-1 increase kept within the physiologic range [6].
Does sermorelin build muscle?
No reviewed trial measures muscle growth from sermorelin. It raises GH and IGF-1, the axis associated with muscle, and reviews discuss GH/IGF-1 modulation as a candidate strategy against age-related muscle loss [13], but a muscle-building effect is not demonstrated for sermorelin itself.
How does sermorelin differ from direct HGH injections?
Sermorelin acts upstream on the pituitary to stimulate the body's own pulsatile GH, leaving somatostatin/IGF-1 feedback intact; injected HGH supplies the hormone directly and bypasses that feedback [13]. An editorial argued the secretagogue route is more physiologic for adult GH insufficiency [4].
Does sermorelin affect the brain?
GHRH-axis activity has been linked to brain function: a randomized GHRH-analog trial reported a favorable effect on cognition in older adults [6], and an MRI study of lifelong GHRH-receptor deficiency found largely preserved brain structure and brain-aging trajectory [14].
Can sermorelin or GHRH improve cognition in older adults?
A randomized, placebo-controlled trial of a GHRH analog in 152 older adults (including 66 with mild cognitive impairment) reported a favorable effect on cognition over 20 weeks, alongside a 117% IGF-1 increase within the physiologic range [6]. The effect was for the stabilized analog tesamorelin, not sermorelin specifically.
What are the side effects of sermorelin?
In pediatric long-term dosing (30 mcg/kg/day), GHRH antibodies appeared in some responders without interfering with growth, and no changes in glucose or lipids were noted [7]. An acute study saw small short-term rises in prolactin, LH, and FSH [8]. Long-term adult anti-aging safety data remain limited [5].
When is the best time to take sermorelin?
Bedtime is the timing used in the literature, because it coincides with the body's natural nocturnal, slow-wave-sleep GH pulse; the pediatric efficacy trial dosed once daily at bedtime subcutaneously [1]. This digest reports that study timing rather than recommending a schedule.
Is 3 months of sermorelin enough?
Study durations varied widely: adult GH/IGF-1 effects were measured over 14 days [2], a GHRH-analog cognition trial ran 20 weeks [6], and pediatric growth trials ran 6 to 24 months [7]. This digest reports those windows rather than recommending a course length.