Skip to content
Peptide Spencer
Partner

Growth hormone axis

Sermorelin

Also known as Sermorelin acetate, GHRH(1-29)-NH2, GRF(1-29), Geref (former US brand)

Limited human data

Growth hormone-releasing hormone (GHRH) receptor agonist; GH secretagogue

No FDA-approved product is marketed today. Not on FDA's 503A category lists (May 14, 2026). Source, May 14, 2026

Identity. Sermorelin is the first 29 amino acids of human GHRH, written GHRH(1-29)-NH2 (Sinha 2020). It is not CJC-1295/Mod GRF(1-29). It is also not the [Nle27] analog used in the Khorram trials. FDA treats distinct active moieties and salts as distinct bulk drug substances. Some older papers write the same molecule as 'GHRH(1-29)NH2' or 'GHRHa' without using the word sermorelin.

At a glance

These dosages are a helpful guide, not a prescription. Every clinician is expected to do their own due diligence before prescribing.

  1. Start

    30 micrograms/kg per day subcutaneously (children with GH deficiency)1

    Human study
Frequency
Once daily at bedtime1
Route
Subcutaneous (sc)1
Course
Up to 1 yr1
Study dose is weight-based for children with GH deficiency; it is not a flat adult dose and no adult dose is validated.
Calculate this dose

Dosing detail

Approved label

Approved label

  • Diagnostic test only, EU Geref 50 SmPC (not a treatment dose)

    1.0 microgram/kg2

    Route
    intravenous
    Frequency
    single injection in the morning after an overnight fast
    Source quote
    A single intravenous injection of 1.0 microgram/kg body weight in the morning following an overnight fast.

Human studies

Human study

  • Previously untreated prepubertal children with GH deficiency

    30 micrograms/kg1

    Route
    subcutaneous (sc)
    Frequency
    once daily at bedtime
    Duration
    up to 1 yr
    n
    110 treated; 86 eligible for efficacy analysis
    Design
    Multicenter, open-label (Geref International Study Group)
    Source quote
    One hundred and ten previously untreated prepubertal GH-deficient children were treated for up to 1 yr in a multicenter, open label study with 30 micrograms/kg GHRH-(1-29)/day, sc, given at bedtime.

    Finding. Mean height velocity rose from 4.1 cm/yr at baseline to 8.0 cm/yr (6 mo) and 7.2 cm/yr (12 mo). The drug was well tolerated.

  • Diagnostic provocative test for GH deficiency in children (single dose, not a treatment regimen)

    1 microg/kg bodyweight3

    Route
    intravenous
    Frequency
    single dose
    Duration
    single test
    n
    not stated in review
    Design
    Narrative drug review (Adis). The same review cites a subcutaneous treatment dose of 30 microg/kg at bedtime.
    Source quote
    Hormone responses to intravenous sermorelin 1 microg/kg bodyweight appear to be a rapid and relatively specific test for the diagnosis of growth hormone deficiency.

    Finding. The review describes the test as rapid and relatively specific for GH deficiency. A normal response does not exclude hypothalamic GHD.

  • Prepubertal children with radiation-induced GH deficiency

    15 micrograms/kg4

    Route
    subcutaneous injection
    Frequency
    twice daily
    Duration
    1 year
    n
    9
    Design
    Multicentre, before-and-after height velocity comparison
    Source quote
    A multicentre study comparing growth before and after 1 year of treatment with GHRH (1-29)-NH2, 15 micrograms/kg twice daily, by subcutaneous injection in children with radiation-induced GH deficiency.

    Finding. Height velocity rose from 3.3 to 6.0 cm/year. This was less than the response to subsequent GH therapy (7.5 cm/year).

  • Prepubertal children with idiopathic short stature (peak GH >20 mU/l, i.e. not GH deficient)

    20 micrograms/kg5

    Route
    s.c. injection
    Frequency
    twice daily
    Duration
    one year
    n
    18 recruited (1 withdrawn before 3 months)
    Design
    Uncontrolled, before-and-after height velocity
    Source quote
    Eighteen short pre-pubertal children (aged 4.3-11.0 years, 17 male) with idiopathic short stature (height < 3rd centile, peak GH to provocative testing > 20 mU/l) were recruited to receive GHRHa 20 micrograms/kg by twice daily s.c. injection for one year.

    Finding. Height velocity rose from 4.8 to 7.2 cm/year, then declined after treatment stopped. Fasting glucose and insulin rose.

  • Healthy, non-obese men aged 64-76 with low baseline IGF-I

    2 mg6

    Route
    subcutaneous self-injection
    Frequency
    nightly
    Duration
    6 weeks
    n
    11
    Design
    Prospective open treatment study. The abstract describes no placebo arm.
    Source quote
    Eleven healthy, ambulatory, non-obese men aged 64 to 76 years with low baseline IGF-I levels were treated at home as outpatients by nightly subcutaneous self-injections of 2 mg GHRH for 6 weeks.

    Finding. Nocturnal GH rose. IGF-I did not change. 2 of 6 strength tests and the abdominal crunch improved. No significant adverse effects were reported.

  • Healthy old men aged 60-78 (n=10) vs young men (n=9)

    0.5 or 1 mg7

    Route
    subcutaneous
    Frequency
    twice daily
    Duration
    14 days, held 14 days, restarted for another 14 days
    n
    10 elderly men (plus 9 young men)
    Design
    Randomized trial: low (0.5 mg) and high (1 mg) dose in random order, 14 days each, with a 14-day nontreatment interval
    Source quote
    Old men then took, randomly, both low (0.5 mg) and high (1 mg) dose GHRH-(1-29) sc injections twice daily for 14 days, with an intervening 14-day nontreatment period.

    Finding. GH parameters rose in a dose-related way. 24-h GH, area under peaks, peak amplitude and IGF-I rose significantly versus old baseline only at the high dose (1 mg twice daily). Over the study there was no effect on fasting glucose, urinary C-peptide, blood pressure, or chemistry and hematology profiles.

  • Healthy adults aged 55-71 (10 women, 9 men). The drug was the [Nle27] analog of GHRH(1-29)-NH2, not sermorelin itself.

    10 microg/kg8

    Route
    s.c.
    Frequency
    nightly (injected at 2100 h)
    Duration
    16 weeks, after 4 weeks of placebo
    n
    19
    Design
    Single-blind, randomized, placebo-controlled
    Source quote
    Ten women and 9 men between the ages of 55-71 yr self-injected placebo (saline) s.c. nightly for 4 weeks followed by 16 weeks of [Nle27]GHRH-(1-29)-NH2 at a dose of 10 microg/kg.

    Finding. IGF-I rose within 2 weeks and stayed elevated for 12 weeks. Lean mass rose in men only. Transient hyperlipidemia occurred.

  • Hypogonadal men on testosterone therapy. Sermorelin was combined with GHRP-2 and GHRP-6, so this is not a sermorelin-alone dose.

    100 µg9

    Route
    subcutaneous injection
    Frequency
    thrice daily (combined GHS therapy)
    Duration
    average 134 days
    n
    14
    Design
    Retrospective review (as described by Sinha 2020)
    Source quote
    These men were given thrice daily 100 µg doses of this combined GHS therapy via subcutaneous injection for an average period of 134 days following which IGF-1, T, FT, E, LH, and FSH were measured at follow-up intervals of 90, 180, and 270 days.

    Finding. IGF-1 increased at all three follow-up timepoints (90, 180 and 270 days).

Clinical practice

Clinical practice

The practice numbers come from a community protocol page (updated Oct 12, 2026) and a vendor page, not from a trial, label or textbook. The community page itself labels the 100-200 mcg dose "Community-practice dose, not one studied in adults." Titration steps, usual maintenance dose and ceiling are blank because no independent source supports a figure. The 100-200 mcg start is about 5 to 10 times below the lowest daily dose studied in adult sermorelin trials. In Corpas 1992, the low dose (0.5 mg twice daily = 1 mg/day) did not significantly raise IGF-I. Once-nightly 2 mg (Vittone) also did not raise IGF-I. Do not present nightly 100-200 mcg as validated to reach an IGF-I target. The weight-based 30 microg/kg dose is the only pediatric regimen with a trial. It is not a flat adult dose.

Start
100 to 200 mcg subcutaneously once daily at bedtime for 4 to 6 weeks (labeled a community-practice dose, not one studied in adults)
Frequency
Once daily at bedtime
Route
Subcutaneous injection (rotate between belly, thigh, and upper arm)
Timing
30 to 60 minutes before sleep
Cycle
No validated cycle length exists. One vendor page says research protocols use 30 mcg/kg nightly for 12+ months, and its quick reference gives a different regimen (200-300 mcg, five nights per week, 3-6 month cycles). Do not cite either as consensus.

Sources

  • Clinical practicePeer-reviewed review9
    thrice daily 100 µg doses of this combined GHS therapy via subcutaneous injection for an average period of 134 days

What clinics and vendors publish

These ranges come from clinic and vendor publications, not studies.

Community-reported
  • Community-reportedOther web source10
    100-200 mcg
  • Community-reportedOther web source10
    Community-practice dose, not one studied in adults.
  • Community-reportedOther web source10
    Once daily at bedtime
  • Community-reportedOther web source10
    Bedtime injection (30-60 minutes before sleep) is ideal because it amplifies your body's natural nighttime GH pulse.
  • Community-reportedOther web source10
    Site: Rotate between belly, thigh, and arm.
  • Community-reportedVendor page11
    Research protocols for Sermorelin typically use 30 mcg/kg, once daily at bedtime for 12+ months with growth monitoring.

Safety

Serious warnings

  • Untreated hypothyroidism or antithyroid drugs may blunt the response. Correct hypothyroidism before dosing. This caution comes from a diagnostic-use label.2
  • Use caution in diabetes mellitus or epilepsy (diagnostic-use label). Obesity, hyperglycaemia and elevated fatty acids are associated with poor GH response. Glucose and insulin rose in children on 20 micrograms/kg twice daily (Kirk 1994).2

Contraindications

  • Hypersensitivity to sermorelin acetate or any excipient (mannitol, sodium phosphate salts).2
  • Pregnancy and lactation.2

Adverse effects

  • Transient facial flushing and pain at the injection site were the most commonly reported adverse events with single IV dosing and repeated once-daily subcutaneous dosing (pediatric review).3
  • Nausea, facial flushing and redness at the injection site were rare. The review judged the safety profile favorable but noted that the studies were small and short.9
  • In the 110-child once-daily 30 micrograms/kg study, general biochemical and hormonal analyses showed no adverse changes. Fasting glucose did not change, and IGF-I was not excessively raised. The drug was well tolerated overall.1
  • In children with idiopathic short stature on 20 micrograms/kg twice daily, fasting blood glucose and insulin levels increased during therapy.5
  • With the [Nle27] analog in adults aged 55-71 (10 microg/kg nightly, 16 weeks), the only adverse effect reported was transient hyperlipidemia, which resolved by the end of the study.8
  • Continuous subcutaneous infusion of GHRH(1-29)-NH2 for 6 months in 6 children with partial GH deficiency produced a biphasic effect. GH rose early, then declined by 3 months, with complete suppression of GH secretion in one child. This was continuous infusion, not nightly injection.12
  • Label: facial heat, flushing and injection-site pain occasionally occur and usually resolve within minutes.2

Monitoring

  • Suggested monitoring, drawn from the evidence above rather than from trial protocols. Check TSH and free T4 at baseline, because hypothyroidism blunts the response. Check glucose and insulin, or HbA1c, periodically (they rose in Kirk 1994 but not in the 14-day Corpas study). Check a lipid panel (transient hyperlipidemia occurred with the analog in Khorram). Monitor blood pressure. Run a pregnancy test before starting (labeled contraindication). Check IGF-1, noting that trials do not show nightly 2 mg raises it. Reassess if the GH response is lost (desensitization was seen with continuous infusion in Tauber).2

Interactions

  • Drugs that affect pituitary GH release may alter the response. These include somatostatin-pathway agents, insulin, glucocorticoids, cyclo-oxygenase inhibitors (aspirin, indomethacin) and anti-muscarinics such as atropine. Beta-adrenergic agonists and blockers may also do so. This is test-context label text. Significance with chronic dosing is unknown.2

Handling

Reconstitution

Follow the dispensing pharmacy's reconstitution instructions. The figures below are arithmetic, not pharmacy instructions. Concentration = mg per vial / mL diluent. 5 mg in 2 mL = 2.5 mg/mL (200 mcg = 0.08 mL; 500 mcg = 0.2 mL; 2 mg = 0.8 mL). 10 mg in 2 mL = 5 mg/mL (200 mcg = 0.04 mL; 500 mcg = 0.1 mL; 2 mg = 0.4 mL). 10 mg in 1 mL = 10 mg/mL (200 mcg = 0.02 mL, 2 units on a U-100 syringe, which invites measurement error). Choose a diluent volume that keeps a 200-500 mcg dose at 0.1 mL or more. Warning: historical Geref vials were 0.5 mg and 1.0 mg (diagnostic ampoule 0.05 mg). Formulary vials are 5 mg and 10 mg, 10 times larger. Do not apply historical vial-based instructions or mental math to formulary vials. No study dose uses a whole vial.

Storage before mixing

Geref 50 diagnostic ampoule only: 2 C to 8 C, protect from light, shelf life 2 years (EU SmPC). Storage for compounded vials is not established. Follow the pharmacy's instructions.

Storage after mixing

Storage for reconstituted compounded multi-dose vials is not established. The Geref 50 SmPC says to reconstitute immediately before use and discard any remainder. Do not extrapolate that to multi-dose vials.2

Evidence

Sermorelin was a US-marketed pediatric GHD product (Geref, NDA 20-443, approved Sept 26, 1997). Pediatric trial data used 30 micrograms/kg/day in an open-label design. Adult data are small and short. They include a randomized low-dose versus high-dose comparison in 10 older men (Corpas 1992, 14 days; IGF-I rose only at 1 mg twice daily), a 2 mg nightly open study (Vittone, n=11; IGF-I unchanged), a placebo-controlled trial of the [Nle27] analog (Khorram, n=19), and a retrospective combination-therapy series. No trial establishes adult clinical outcomes or a clinical dose range. The US Geref treatment label text was not reviewed. Label information comes from the EU Geref 50 diagnostic SmPC.

Mechanism

Sermorelin is a synthetic GHRH(1-29) fragment. It binds the pituitary GHRH receptor and raises cAMP, which prompts the pituitary to release endogenous growth hormone. After IV dosing, plasma half-life is 6-7 minutes and the response lasts 2-3 hours (Geref 50 EU SmPC). One review gives 10-20 minutes for subcutaneous dosing and a GH effect of about 2 hours. The IGF-I response depends on dose and frequency.269

Availability

Amounts offered

  • 5 mg
  • 10 mg

Custom strengths on request.

References

According to PubMed

  1. 1Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy. Geref International Study Group.J Clin Endocrinol Metab 81(3):1189-96, 1996
  2. 2Geref 50 (sermorelin acetate 50 microgram ampoule) Summary of Product Characteristics, diagnostic useIrish Medicines Board / Serono, printed 13/07/2006, 2006
  3. 3Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency.BioDrugs 12(2):139-57, 1999
  4. 4Treatment of radiation-induced growth hormone deficiency with growth hormone-releasing hormone.Clin Endocrinol (Oxf) 46(5):571-8, 1997
  5. 5Treatment with GHRH(1-29)NH2 in children with idiopathic short stature induces a sustained increase in growth velocity.Clin Endocrinol (Oxf) 41(4):487-93, 1994
  6. 6Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men.Metabolism 46(1):89-96, 1997
  7. 7Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men.J Clin Endocrinol Metab 75(2):530-5, 1992
  8. 8Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women.J Clin Endocrinol Metab 82(5):1472-9, 1997
  9. 9Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males.Transl Androl Urol 9(Suppl 2):S149-S159 (PMC7108996), 2020
  10. 10Sermorelin dosing & administration (Peptide Initiative; owner-authored, reviewed by its research team; no conflict-of-interest statement on the page)peptideinitiative.com, last updated Oct 12, 2026, 2026
  11. 11Sermorelin (Peptide Protocol Wiki; site also sells peptide-related products)peptideprotocolwiki.com
  12. 12Growth hormone (GH) profiles in response to continuous subcutaneous infusion of GH-releasing hormone(1-29)-NH2 in children with GH deficiency.Acta Paediatr Suppl 388:28-30, 1993
  13. 13Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?Clin Interv Aging 1(4):307-8 (editorial; PMC2699646), 2006
  14. 14Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act (content current as of 05/14/2026; no mention of sermorelin in page text)FDA, 2026
  15. 15Geref (Injection) consumer drug page; reports brand and generics discontinued in the US (cited from search result; page not fetched)Drugs.com, 2026
  16. 16Determination That GEREF (Sermorelin Acetate) Injection ... Were Not Withdrawn From Sale for Reasons of Safety or EffectivenessFederal Register 78(42):14096, 2013

Last reviewed 2026-10-14. 52 figures checked against their sources. How this works