Rankings / Comparisons

Sermorelin vs Ipamorelin

GHRH analog vs ghrelin-receptor agonist — both push the GH axis but at different control points.

Bottom line

On the composite score, Sermorelin (C+, 5.6/10) edges out Ipamorelin (C, 4.9/10) — but the right pick depends on the specific outcome you're optimising for.

Sermorelin

C+ 5.6/10

Evidence
Weak-Moderate (Vittone 1997 J Clin Endocrinol Metab — n=19 aged 55-71, 10 mcg/kg SC nightly x 16 wk, increased nocturnal GH, IGF-1, lean mass +1.26 kg, skin thickness, well-being); Strong (pediatric GHD diagnostic — historical FDA approval 1997 as Geref); never formally FDA-approved for adult anti-aging use (4.5/10)
Benefit
Med (5/10)
Risk
Low-Med (injection site reactions most common; preservation of physiological feedback minimizes HPA disruption; no measurable cortisol or prolactin elevation; theoretical insulin resistance at chronic supraphysiological exposure) (7/10 safety)
Legality
Originally FDA-approved (Geref, Serono 1997 for pediatric GHD diagnosis); commercially withdrawn 2008 (Serono cited economic — not safety — reasons); currently legally compoundable from 503A/503B pharmacies in the US — SURVIVED the April 22 2026 FDA 503A Category 2 actions that removed 12 other peptides including dihexa
Dose
Typical biohacker anti-aging: 200-500 mcg subQ at bedtime; pediatric GHD diagnostic 1 mcg/kg single IV/SC
Class
Anabolic
Last reviewed
Jun 8, 2026

Read Off Label grades Sermorelin as C+ (5.6/10) based on weak-moderate evidence, med benefit magnitude, and a low-med-risk safety profile.

The most "physiologic" GH-axis intervention because it preserves pulsatile release and somatostatin feedback — the short half-life (~10 min) means the pituitary continues to follow its endogenous rhythm rather than being chronically activated.

Typical use: Typical biohacker anti-aging: 200-500 mcg subQ at bedtime; pediatric GHD diagnostic 1 mcg/kg single IV/SC — Originally FDA-approved (Geref, Serono 1997 for pediatric GHD diagnosis); commercially withdrawn 2008 (Serono cited economic — not safety — reasons); currently legally compoundable from 503A/503B pharmacies in the US — SURVIVED the April 22 2026 FDA 503A Category 2 actions that removed 12 other peptides including dihexa.

What it is

The most "physiologic" GH-axis intervention because it preserves pulsatile release and somatostatin feedback — the short half-life (~10 min) means the pituitary continues to follow its endogenous rhythm rather than being chronically activated. Geref (Serono) was withdrawn 2008 for commercial reasons after the small pediatric-GHD market couldn't sustain manufacturing — FDA explicitly confirmed the withdrawal was NOT for safety or efficacy concerns. Remains the most-prescribed GHRH analog in compounding-pharmacy peptide protocols and is legally compoundable as of the April 2026 FDA 503A Category 2 update (sermorelin was NOT among the 12 peptides removed). **Clinical evidence**: the canonical aging trial remains Vittone 1997 — modest but real lean mass and IGF-1 effects after 16 weeks. No new major RCTs in 2024-2026 — the evidence base is thin and old. **Trend in practice**: increasingly displaced by CJC-1295 + ipamorelin combo stacks in compounding-clinic protocols because the dual-pathway combo produces larger measurable effects (at the cost of flattening the physiological pulse with the DAC variant, or requiring multiple daily injections without DAC). Sermorelin remains the choice for "most physiologic" GH-axis stack and for patients sensitive to flushing or water retention common with CJC. **Compounding-pharmacy access caveat**: sourcing from a legitimate 503A or 503B pharmacy is essential — gray-market "sermorelin" in research-chemical channels is poorly characterized. **Sport context**: not specifically named on the WADA Prohibited List but GHRH analogs as a class fall under WADA S2 (peptide hormones).

Mechanism

N-terminal 29-amino-acid fragment of endogenous GHRH; native receptor agonist at GHRH-R; very short half-life (~10 min) — preserves physiological GH pulsatility and somatostatin feedback; binds the same pituitary receptor as endogenous GHRH so the release pattern remains pulsatile rather than tonic (contrast: CJC-1295 with DAC flattens the pulse over multi-day exposure)

Full Sermorelin review →

Ipamorelin

C 4.9/10

Evidence
Weak (small human trials for postoperative ileus, safety); anecdotal for recovery/body composition (3/10)
Benefit
Med (5/10)
Risk
Low-Med (injection site; mild cortisol/prolactin effects; muscle strain from rapid recovery anecdotally) (7/10 safety)
Legality
Research peptide; not FDA-approved; banned sport
Dose
200-300 mcg subQ 2-3x/day (commonly stacked with CJC-1295)
Class
Anabolic
Last reviewed
Jun 8, 2026

Read Off Label grades Ipamorelin as C (4.9/10) based on weak evidence, med benefit magnitude, and a low-med-risk safety profile.

The 'cleanest' of the GHRPs — minimal effect on cortisol and prolactin.

Typical use: 200-300 mcg subQ 2-3x/day (commonly stacked with CJC-1295) — Research peptide; not FDA-approved; banned sport.

What it is

The 'cleanest' of the GHRPs — minimal effect on cortisol and prolactin. Classic stack: CJC-1295 (no DAC) + Ipamorelin to produce a synchronized GH pulse. Ph2 studies for postoperative ileus in Helsinn development program; no approval. Product-quality caveat: a 2026 preprint testing consumer "research-grade" peptides found 42-71% failed purity benchmarks and ~15% had measurable endotoxin contamination — gray-market sourcing is a real safety risk.

Mechanism

Selective GHS-R1a agonist; releases GH from pituitary with minimal impact on cortisol, prolactin, ACTH (unlike GHRP-2/6); short plasma half-life (~2 hr)

Full Ipamorelin review →

Common questions

Which is better, Sermorelin or Ipamorelin?
On the composite score, Sermorelin (C+, 5.6/10) edges out Ipamorelin (C, 4.9/10) — but the right pick depends on the specific outcome you're optimising for.
What's the difference between Sermorelin and Ipamorelin?
GHRH analog vs ghrelin-receptor agonist — both push the GH axis but at different control points.
Can you take Sermorelin and Ipamorelin together?
Read Off Label doesn't make stack recommendations — see the disclaimer. Both compounds have individual mechanism, dose, and risk profiles documented on their respective pages; combining them is a clinical question that depends on the goal, indication, and other context.

This is an independent synthesis of published research by a non-clinician. Comparison-page verdicts use the composite Read Off Label score as a tiebreaker, but the right pick for any given person depends on indication, context, and clinician input. See the full disclaimer and methodology.