Sermorelin held an FDA approval as Geref, but both products are discontinued and no current US label exists to consult. The figures below record what published studies administered and what research and clinic sources report. They are data points, not a protocol for the reader.
The short answer
The doses used in published research were weight-based and larger than the flat figures in circulation. The paediatric treatment study used 15 µg/kg twice daily subcutaneously (Ogilvy-Stuart et al., Clin Endocrinol 1997), and the older-adult study used 10 µg/kg nightly (Khorram et al., J Clin Endocrinol Metab 1997) — about 700 µg per dose for a 70 kg adult. Research and clinic sources most often describe a flat 200–500 µg subcutaneously at bedtime — roughly a third to three-quarters of the per-dose amount used in the published adult study.
Doses used in published studies
15 µg/kg subcutaneously, twice daily, for one year — nine prepubertal children with radiation-induced GH deficiency. Height velocity rose from 3.3 to 6.0 cm/year (p = 0.004); switching to growth hormone the following year produced 7.5 cm/year. No adverse events attributable to the therapy, and no adverse changes in three-monthly biochemistry, haematology, lipids or thyroid function (Ogilvy-Stuart 1997).
10 µg/kg nightly for 16 weeks — 19 healthy adults aged 55–71, using the closely related [Nle27]GHRH-(1-29)-NH2, after a four-week saline run-in. IGF-1 rose within two weeks; lean body mass increased in men only; skin thickness increased in both sexes; sleep was unchanged (Khorram 1997).
Geref product strengths — 0.05 mg per ampoule for the diagnostic formulation (NDA 019863, approved December 1990) and 0.5 mg and 1 mg vials for the treatment formulation (NDA 020443, approved September 1997) (Drugs@FDA). Both are discontinued.
Commonly reported patterns
Research, wellness-clinic and community sources most often describe 200–500 mcg subcutaneously once daily at bedtime, on an empty stomach, sometimes paired with a ghrelin-receptor agonist such as ipamorelin. Courses of three to six months with periodic IGF-1 checks are frequently described in clinic settings.
These are flat doses, not weight-based, and they sit below the per-dose amounts used in the published adult study. No regulator currently reviews or supports them, and no controlled trial has evaluated this schedule for the outcomes it is offered for.
Why bedtime dosing, and what the evidence says about it
The rationale is that the body's largest natural GH pulse occurs during early slow-wave sleep, so a short-acting GHRH analogue given at bedtime reinforces a pulse that is already happening rather than creating an artificial one. The published adult study did dose nightly, which is consistent with the reasoning (Khorram 1997).
Two honest qualifications. No study has compared bedtime with any other schedule for this compound, so the timing is a mechanistic argument rather than a tested one. And the same study that dosed nightly reported that sleep itself was unaffected in both men and women — worth knowing, given how often improved sleep is the reason sermorelin is offered.
The paediatric study, by contrast, used twice-daily dosing, which was also the schedule of the approved treatment product. Two injections a day for a smaller effect than one daily growth hormone injection is a large part of why the product lost commercially (Walker, Clin Interv Aging 2006).
The pharmacology that shapes the schedule
Sermorelin is GHRH(1-29) with no stabilising modifications, and its plasma half-life in humans is roughly 10 to 20 minutes, limited mainly by renal ultrafiltration and enzymatic degradation at the N-terminus (Esposito et al., Adv Drug Deliv Rev 2003). Everything about the dosing follows from that number: injections rather than tablets, daily or twice-daily rather than weekly, and the whole engineering effort behind modified GRF 1-29 and CJC-1295 with DAC, which exist to make that half-life longer.
A second constraint is biological rather than chemical. Because sermorelin works by asking the pituitary to release growth hormone, it does nothing when the pituitary cannot — which is why the Geref label instructed that children who did not adequately respond to a Geref stimulation test, defined as a peak GH below 2 ng/mL, "should be excluded from Geref therapy" (FDA briefing document, PCAC October 2024). Dose escalation cannot overcome an unresponsive pituitary.
Why oversight matters
The most useful thing a clinician adds here is measurement. IGF-1 is a direct readout of whether the compound is doing anything — it rose within two weeks in the older-adult study — and it is the parameter that distinguishes an effective dose from an expensive placebo, and an excessive one from an appropriate one. Fasting glucose is the other, since the wider secretagogue class is associated with decreased insulin sensitivity (Sigalos & Pastuszak, Sex Med Rev 2018), even though the GHRH analogue studied in older adults improved it in men.
On the product side: sermorelin ships as a lyophilised powder requiring reconstitution, and the delivered dose is set by how much bacteriostatic water is added, not by the vial label — with the drawn volume read in syringe units, routinely misread as micrograms. Material obtained outside a pharmacy supply chain also carries none of the identity, purity and endotoxin assurances that the discontinued Geref product did.
Sermorelin is prohibited in sport at all times under WADA section S2 as a growth hormone-releasing factor (WADA Prohibited List).
See also sermorelin side effects and the research and evidence overview.