Growth Hormone

Sermorelin

GRF 1-29 · Geref

GHRH(1-29). Historical Geref was a US pediatric product and is not a current anti-aging NDA. Nightly research-chem shots are not mcg/kg Geref. Not somatropin. Stack slogans are not a label.

Not FDA-approved - research chemicalWADA (S2) - prohibited in sport at all times
Reviewed by CalcMyPeptide Editorial Team
Last updated: August 2026Evidence: Moderate2 peer-reviewed citations
Typical research dose
200-300 mcg/day
Frequency
1× daily (before bed)
Half-life
~11-12 minutes (IV); ~20-30 minutes (SC)
Common vials
2 mg / 5 mg / 9 mg
CAS
86168-78-7
Molecular weight
3357.93 g/mol

Use-case scores

0–10 against the evidence we have, not a gym ranking. Hidden domains do not apply here.

  • Muscle / recomp4/10

    Pediatric GHD literature and adult wellness use. Geref is not a living US brand. Community/small-human after haircut: 4. Not 7 for “FDA-approved anti-aging.”

  • Recovery & sleep3.5/10

    Nocturnal GH pulse is physiology. Vivid-dream anecdotes are not a sleep RCT.

Compound card

Sequence
GHRH(1-29)-NH2
Class
GHRH fragment (historical Geref; withdrawn US brand, not current rhGH)
Formula
C149H246N44O42S1
Status
Not FDA-approved · research use
Dose it
5 mg + 2.5 mL BAC water → 2 mg/mL · 200 mcg ≈ 10 units (U-100)
Open in calculator

How it works

Sermorelin (GRF 1-29) is a bioidentical analog of natural Growth Hormone Releasing Hormone (GHRH), consisting of the first 29 amino acids of the 44-amino-acid GHRH peptide. These 29 amino acids contain the full biological activity of the complete molecule.

Sermorelin stimulates pituitary somatotroph cells to produce and release growth hormone in a pulsatile, physiological pattern. Unlike exogenous HGH, it still has to go through the pituitary, so output is capped by somatotroph reserve and somatostatin. That is not a guarantee of “no supraphysiological GH.” Geref was FDA-approved for pediatric use and is not a current US brand. Adult anti-aging use is off-label compounded peptide, not that label.

Source: PMID: 9677584

Background & History

Sermorelin is GHRH(1-29). Geref was a US pediatric GHD product and is not a current anti-aging NDA. Walker 2006 (PMID 18046908) is an editorial. Prakash/Goa 1999 (PMID 18031173) is the BioDrugs review.

Research Use Cases

  • ✓GHRH(1-29) identity vs tesamorelin vs Mod GRF vs somatropin
  • ✓Historical Geref, not a current anti-aging NDA
  • ✓Not a 2–5× GH stack slogan

Dosing

PhaseDoseFrequencyNotes
Starting / Clinical200 - 300 mcgNightly before bed (SC)Standard clinical dose. Inject on an empty stomach (1+ hours after last meal) to maximize the GH pulse.
Standard Stack250 mcg Sermorelin + 200 mcg IpamorelinNightly before bed (SC)Common GHRH + GHRP mix. Two receptors, not a labeled 2–5× GH claim.

Administration

Route / form
Subcutaneous injection
Timing
Before bed on an empty stomach (no food 1+ hours prior).
Empty stomach?
Yes - Empty stomach (typical for this injectable class).

Timeline

Week 1-4
Improved sleep quality. Vivid dreams are common (GH pulse during REM). Mild injection site reactions.
Month 1-3
Enhanced recovery, improved body composition, skin quality improvements begin.
Month 3-6
Peak benefits - sustained lean mass improvements, fat loss, improved IGF-1 levels.

Who it is for

Need GHRH(1-29) identity

Moderate

This is the fragment. Geref history is pediatric, not a 2026 anti-aging NDA.

Need rhGH itself

Low

That is somatropin. Different page, different suppression profile.

Reconstitution

VialWaterConcentrationExample dose
5 mg lyophilized2.5 mL BAC2 mg/mL200 mcg = 0.10 mL = 10 units on a U-100.

Change vial size or water volume? Open the reconstitution calculator.

Safety & Considerations

Geref is not a current US brand. Compounded sermorelin is not that label. Flushing and headache show up. Active malignancy is a GH-class conversation. Not “safer HGH forever.”

Regulatory & Legal Status

FDA Status (US)
Research Only

Former FDA approval withdrawn; available in US via licensed compounding pharmacies

WADA Status (2026)
Prohibited (S2)

Competitive athletes subject to anti-doping controls should not use Sermorelin.

Classification

Compounded Drug (Rx)

US Compounding: Available via licensed pharmacy Rx

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Limits of current evidence

  • Walker’s PMID is 18046908, not 18046879. It is an editorial.
  • Pediatric mcg/kg Geref math is not 250 mcg bedtime wellness.
  • “2–5× GH with ipamorelin” is a stack slogan, not a labeled endpoint.
  • Geref withdrawal means “FDA-approved” is history, not a 2026 pharmacy SKU.

Verdict

Sermorelin is GHRH(1-29). Geref was a US product for pediatric GHD diagnosis/treatment and is not a current anti-aging NDA. Walker 2006 is an editorial (PMID 18046908), not a Phase 3. Prakash/Goa 1999 (PMID 18031173) is the BioDrugs review. It is not “safer HGH forever.”

Interactions & Contraindications

Same GH-class cautions as other GHRH analogs: glucose, active cancer, glucocorticoids blunt the pulse.

Synergies & Common Stacks

GHRH + GHRP mix. Clinics sell it. Dual-receptor physiology is real. Wellness-clinic popularity is not a labeled endpoint.

Sermorelin vs. Tesamorelin

Canonical comparison: Sermorelin vs Tesamorelin

AttributeSermorelinTesamorelin
FDA StatusNot FDA-approved (was revoked)FDA-approved (Egrifta® - HIV lipodystrophy)
Half-Life~11–13 minutes~26 minutes (longer-acting)
PotencyModerate GH stimulationStronger - more potent GHRH analog
Best ForGeneral GH/IGF-1 anti-aging protocolVisceral fat reduction (clinical + wellness)
WADA StatusProhibited (S2)Prohibited (S2)
AvailabilityCompounded pharmacy (Rx)Branded Rx + compounded

Verdict: Tesamorelin is the more potent and clinically validated GHRH analog with FDA approval for lipodystrophy. Sermorelin is more widely compounded and used for general anti-aging GH optimization at lower cost.

Frequently Asked Questions

Why is Sermorelin preferred over HGH?▼
It asks the pituitary to pulse GH instead of injecting GH. That is a different suppression profile, not a proof it is safer forever or that Geref is still on the US market.
What is the best time to inject Sermorelin?▼
Community use is bedtime, fasted. Pediatric Geref was mcg/kg. Those are not the same protocol.
Can Sermorelin be combined with Ipamorelin?▼
Clinics mix GHRH + GHRP because the receptors differ. Treat “2–5× more GH” as a slogan unless you have a paper in your hand for that mix and those doses.

References

  1. Walker RF “Sermorelin: a better approach to management of adult-onset GH insufficiency?.” Clinical Interventions in Aging (2006). PMID: 18046908
  2. Prakash A, Goa KL “Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency.” BioDrugs (1999). PMID: 18031173

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