Sermorelin Dosage, half-life & reference guide
Also known as GHRH 1-29 · GRF 1-29
A synthetic copy of the first 29 amino acids of your natural growth hormone releasing hormone: it prompts your pituitary to release its own GH, keeping the body's feedback loops in play.
- Studied range
- 200–500 mcgstarting dose 200 mcg
- How often
- Daily
- Half-life
- ~11–12 min
- Evidence
- ●●●
Established - Route
- SubQ injection
Studied in research — not a recommendation.
How it works.
Synthetic analogue of endogenous GHRH. Stimulates the pituitary to produce and secrete GH naturally. Considered a more physiological approach to GH optimization compared to exogenous GH.
Commonly reported: Deeper sleep and vivid dreams in the first weeks, with gentle, slow-building effects, milder than CJC/ipamorelin. It was FDA-approved as a diagnostic test (1990) and to treat GH deficiency in children (1997) until the maker discontinued it in 2008, not for safety reasons.
Half-life & active level
The half-life of Sermorelin is ~11–12 min (US Geref label, after IV or SubQ).
Here's how a typical Sermorelin schedule plays out over 48 hours (one-compartment estimate).
An estimate from the half-life above, not a measurement. See your own curve build live in the half-life calculator.
Where Sermorelin works.
Brain, nerves & sleep
Reported by users. Commonly reported: sleep improves first, often within the first week, with vivid dreams.
Skin & hair
Reported by users. Commonly reported: measurable body-composition changes and better skin by now.
Muscle
Reported by users. Commonly reported in weeks 2 to 6: faster recovery from training, better skin and deeper, longer sleep.
An area lights for what a peptide is used for and what people report, with the evidence beside it. It isn’t a promise that it works there.
Week by week.
What to expect in the first 8 weeks
- Onset
- 1–2 weeks
- Peak effect
- 3–6 months
- Duration
- 3–6 months
Day 1–14Community
Sleep is the first signal
Sermorelin works through your own pituitary, so the first effects are subtle. Commonly reported: sleep improves first, often within the first week, with vivid dreams. Pre-bed dosing aims at your natural nighttime GH pulse.
The science
Sermorelin (GHRH 1-29) stimulates pituitary somatotrophs to release endogenous GH. Pre-sleep dosing aims to amplify the natural nocturnal GH pulse of the first hours of slow-wave sleep. FDA-approved as Geref (diagnostic from 1990; pediatric GH-deficiency treatment from 1997) until 2008.
Sources- Walker (2006)
- Federal Register (FDA) (2013)
Updated Sep 2026
Day 14–42Community
Recovery and skin are responding
Commonly reported in weeks 2 to 6: faster recovery from training, better skin and deeper, longer sleep. This is the slow-build phase; sermorelin rewards patience.
The science
Unlike synthetic GH, sermorelin works through the pituitary's own pulses and feedback loops, and IGF-1 rises gradually over weeks, not days. Whether that means better long-term pituitary health hasn't been studied.
Sources- Walker (2006)
Updated Sep 2026
Day 42–180Clinical
The long game is paying off
Community protocols run 3–6 months. Commonly reported: measurable body-composition changes and better skin by now. Many anti-aging physicians prefer it because it works through your body's own GH regulation rather than overriding it.
The science
Sermorelin has 1–3 years of pediatric safety data (Prakash & Goa 1999), unusual for GH peptides; there are no multi-year adult data. The claim that a "pituitary training" effect outlasts dosing comes from an editorial citing rat work (Walker 2006); no human data show benefits persisting after stopping.
Sources- Prakash & Goa (1999)
- Walker (2006)
Updated Sep 2026
Any dayClinical
What Sermorelin is built on
One of the few GH peptides with real FDA history: approved as Geref for GH-deficiency testing (1990) and treatment in children (1997), then discontinued in 2008 for non-safety reasons. A first-generation peptide that newer ones like CJC-1295 were built on; adult use rests on small GHRH trials in older adults.
The science
Sermorelin is the first 29 amino acids of endogenous GHRH (44 amino acids). FDA approvals covered diagnostic testing (1990) and treatment of idiopathic GH deficiency in children (1997); they were withdrawn in 2009 after the maker stopped production, and FDA determined in 2013 that this wasn't for safety or effectiveness reasons. The newer CJC-1295 added amino acid substitutions for improved half-life and potency, but sermorelin remains the most physiologically conservative option.
Sources- Federal Register (FDA) (2013)
- Prakash & Goa (1999)
Updated Sep 2026
Any dayClinical
Where Sermorelin sits in the GH family
Sermorelin is the original GHRH analog — a near-exact copy of your own GHRH, which makes it the gentlest and most physiological of the family but also the shortest-acting (~10–20 minutes). CJC-1295 is essentially Sermorelin with stabilizing tweaks for a longer, more durable pulse; Tesamorelin is the longer, visceral-fat-focused GHRH with the most clinical data. If you want the lightest GHRH and don't mind a slower build, Sermorelin is the conservative pick.
The science
Sermorelin (GHRH 1-29, ~11–12 min half-life) is the native-sequence GHRH analog; CJC-1295/Mod GRF 1-29 adds substitutions for enzymatic resistance and a cleaner pulse; Tesamorelin is a stabilized GHRH analog FDA-approved for HIV lipodystrophy with the strongest visceral-fat data. All three are GHRH-side (baseline) agents typically paired with a GHRP for a fuller pulse. Positioning only — established pharmacology, no new claims.
Sources- Walker (2006)
Updated Sep 2026
Day 1 is the day you start it.
Formerly FDA-approved diagnostic and pediatric GH-deficiency treatment. Slower onset than Ipamorelin/CJC combos per community consensus.
Moderate evidence
Mixing and a typical run.
Example numbers
Reconstitution example
Reconstitute a 5 mg vial of Sermorelin with 2 mL of bacteriostatic water and a 200 mcg dose is 8 units on a U-100 syringe, about 25 doses per vial.
- Vial
- 5 mg
- Water
- 2 mL
- Amount
- 200 mcg
Draw to8 units
0.3 mL insulin syringe · 30 units
Run notes
- Cycle
- 3–6 months common; considered a more physiological approach so longer cycles are used.Community practice — opinions vary. Not a clinical recommendation.
- Timing
- Pre-sleep injection aligns with natural GH secretion. Fasted preferred.
- Route
- SubQ injection
- Stacks
- Ipamorelin, MOTS-c, BPC-157
Safety.
Common side effects
- Headache
- Flushing
- Dizziness
- Nausea
- Injection site reaction
- Water retention
Goes with.
Compared with.
Questions people ask.
What is Sermorelin?
A synthetic copy of the first 29 amino acids of your natural growth hormone releasing hormone: it prompts your pituitary to release its own GH, keeping the body's feedback loops in play.
How is Sermorelin dosed in research?
The research range for Sermorelin is 200–500 mcg, daily, before bed, with a 200 mcg starting dose. Studied in research — not a recommendation.
How long does Sermorelin last?
The half-life of Sermorelin is ~11–12 min (US Geref label, after IV or SubQ).
What do people report on Sermorelin?
Commonly reported on Sermorelin: deeper sleep and vivid dreams in the first weeks, with gentle, slow-building effects, milder than CJC/ipamorelin. It was FDA-approved as a diagnostic test (1990) and to treat GH deficiency in children (1997) until the maker discontinued it in 2008, not for safety reasons.
Is Sermorelin safe?
The research basis for Sermorelin is established: clinical trials or FDA-approved use exists. Common side effects in the library: headache, flushing, dizziness, nausea, injection site reaction and water retention.
What does Sermorelin stack with?
Common stacks for Sermorelin: Ipamorelin, MOTS-c and BPC-157.
Research.
Reference.
- Cadence
Daily
Daily, before bed
- Half-life
~11–12 min
~11–12 min (US Geref label, after IV or SubQ)
- Research basis
●●●
EstablishedClinical trials or FDA-approved use exists
PepVault for iPhone
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