Quick answer: the only official sermorelin dosage came from its former brand, Geref: 30 mcg per kg of body weight injected under the skin once daily at bedtime for children with growth hormone deficiency, or a single 1 mcg per kg IV dose as a pituitary test.[1][2] Adult studies used 0.5 mg to 2 mg once or twice daily, but Geref was discontinued in 2008 and no current label covers adults.[3][5][6]
This guide covers what the Geref program used, what doses were tested in older adults, how often sermorelin was injected and why, and what to ask a clinician. For background, see our sermorelin profile and the wider growth hormone peptides hub.
What sermorelin is, and why dosing is short-acting
Sermorelin is the first 29 amino acids of growth hormone-releasing hormone (GHRH), the shortest piece that keeps the hormone’s full activity.[1] It tells the pituitary gland to release a pulse of growth hormone, which then raises IGF-1. Because it acts briefly, studies gave it once or twice a day rather than weekly.
That makes it different from long-acting GHRH analogs. See CJC-1295 vs sermorelin and tesamorelin vs sermorelin for how those compare.
The former Geref label doses
FDA approved two Geref products:[3][4]
- A diagnostic ampule (0.05 mg), approved in December 1990, for testing whether the pituitary can release growth hormone.
- Treatment vials (0.5 mg and 1.0 mg), approved in September 1997, for idiopathic growth hormone deficiency in children with growth failure.
EMD Serono discontinued both in 2008, and FDA withdrew the approvals in June 2009 at the company’s request. In 2013, FDA determined they were not withdrawn for safety or effectiveness reasons.[3] The full Geref package insert is not posted on Drugs@FDA, so the doses below come from the published review and trials.
| Use | Dose | How given |
|---|---|---|
| Pituitary test (diagnosis) | 1 mcg per kg, single dose | Into a vein |
| Growth hormone deficiency in children | 30 mcg per kg, once daily | Under the skin at bedtime |
A 1999 drug review described the 30 mcg per kg bedtime dose as the recommended treatment dosage, and the single 1 mcg per kg IV dose as the test dose, used alongside conventional growth hormone tests.[1]
What the 30 mcg/kg dose achieved in children
The main pediatric trial, run by the Geref International Study Group, treated 110 children with growth hormone deficiency at 30 mcg per kg once nightly for up to a year.[2]
- Average growth rate rose from 4.1 cm a year before treatment to 8.0 cm a year at 6 months and 7.2 cm a year at 12 months.
- 74% were considered good responders at 6 months.
- Bone age did not advance faster than height, fasting glucose did not change, and IGF-1 did not rise excessively.
This was open-label, without a placebo group, and 86 of the 110 children qualified for the efficacy analysis.[2]
Other pediatric dosing schedules
Researchers outside the Geref program tested different schedules:
| Study | Who | Dose |
|---|---|---|
| Shanghai, randomized[7] | 60 children, hypothalamic growth hormone deficiency | 30 or 60 mcg/kg/day by continuous infusion, vs growth hormone |
| UK, radiation-induced deficiency[8] | 9 children | 15 mcg/kg twice daily under the skin |
| London, idiopathic short stature[9] | 18 children | 20 mcg/kg twice daily under the skin |
Two lessons came from these. Doubling the dose from 30 to 60 mcg per kg did not improve growth in the Shanghai trial, and both doses worked less well than growth hormone itself (about 9.2 vs 14.6 cm a year).[7] And in the London study, growth slowed again in the first 3 months after stopping.[9]
Sermorelin doses studied in adults
There has never been an approved adult sermorelin dosage. The adult data come from small studies of healthy older men:
| Study | Dose | Length | Result |
|---|---|---|---|
| National Institute on Aging[5] | 0.5 mg or 1 mg twice daily | 14 days each | Only 1 mg twice daily significantly raised growth hormone and IGF-1 |
| Johns Hopkins[6] | 2 mg once nightly | 6 weeks | Raised nighttime growth hormone; IGF-1, body composition and blood sugar unchanged |
Key points:
- Twice daily beat once nightly. In the National Institute on Aging study, 10 older men reached IGF-1 levels similar to young men on 1 mg twice daily, while 0.5 mg twice daily did not significantly raise IGF-1.[5]
- A larger single dose was not enough. In the Johns Hopkins study, 11 men injected 2 mg nightly at home. Two of six strength measures improved, but the authors concluded single nightly doses were less effective than multiple daily doses.[6]
- Sleep research used far smaller IV doses. A Belgian study gave young men 0.3 mcg per kg into a vein during the night; a late-night dose increased deep sleep.[10] That was a research setting, not a treatment schedule.
None of these studies tested long-term use, and none was designed to show anti-aging benefits.
Injections, timing and frequency
Most sermorelin dosing searches are really about injections. Here is what the studies did:
- Route: injection under the skin for treatment; into a vein only for the diagnostic test or sleep research.[1][10]
- Timing: the pediatric Geref schedule used bedtime, and the Johns Hopkins study used nightly self-injection.[2][6]
- Frequency: once daily in the Geref program, twice daily in several UK pediatric and US adult studies.[2][5][9]
- Weight-based or fixed: children were dosed per kilogram, while the adult studies used fixed milligram doses.
For help reading milligrams and micrograms on a prescription, see our guide on how to calculate peptide dosage and our peptide calculator. These tools explain the math; they do not set a dose.
Why there is no current approved dose
Because Geref is discontinued, no current FDA label tells clinicians how to dose sermorelin for any condition.[3] The adult studies above were small, short and focused on hormone levels rather than health outcomes. A clinician who prescribes sermorelin is making a judgment without a label to follow.
Athletes should also know that sermorelin is banned in sport. The U.S. Anti-Doping Agency says a therapeutic use exemption is highly unlikely, because sermorelin is not a first-line treatment for growth hormone deficiency.[12]
For side effects at these doses, see our sermorelin side effects guide. For how sermorelin compares with a ghrelin-receptor peptide, see sermorelin vs ipamorelin.
Questions to ask a clinician
- What condition are we treating, and is there an FDA-approved option for it?
- Which study is this dose based on, and how does it compare with the 0.5 to 2 mg adult doses that were tested?
- Should it be once or twice daily, and at what time?
- Which blood tests (IGF-1, fasting glucose) will you check, and how often?
- Who made the product, and what quality testing does the pharmacy do?
Talk to a licensed clinician before starting or changing any hormone-related treatment.
