Skip to content
The Peptide Effect
Comparison

Ipamorelin vs Sermorelin

Ipamorelin and sermorelin both stimulate natural growth hormone release but work through entirely different receptor pathways. Ipamorelin is a selective growth hormone releasing peptide (GHRP) that mimics ghrelin at the pituitary level without significantly raising cortisol or prolactin, while sermorelin is a growth hormone releasing hormone (GHRH) analog that acts on the GHRH receptor to trigger GH secretion. Because they target different receptors, the two are often stacked for a synergistic GH pulse far greater than either peptide alone.

Side-by-side comparison diagram of Ipamorelin and Sermorelin mechanisms of action
Conceptual comparison — not to scale

Head-to-Head Comparison

CriteriaIpamorelinSermorelin
Primary mechanismSelective ghrelin receptor (GHS-R1a) agonist at the pituitaryGHRH receptor agonist — mimics endogenous GHRH(1-29)
Peptide classGrowth hormone releasing peptide (GHRP)Growth hormone releasing hormone (GHRH) analog
SelectivityHighly selective — minimal cortisol and prolactin elevationModerate selectivity — slight cortisol and prolactin increase possible
Typical dosage200–300 mcg subcutaneous, 1–3× daily200–300 mcg subcutaneous, once daily before bed
Half-life~2 hours~10–20 minutes
GH release patternStrong, clean GH pulse with fast onsetPhysiologic GH pulse that mimics natural GHRH signaling
Effect on hungerMinimal appetite increase despite ghrelin mimicryNo significant appetite stimulation
FDA historyNo FDA approval; research chemical / compounding usePreviously FDA-approved (Geref) for pediatric GH deficiency; brand discontinued but available via compounding
Side effect profileVery mild — occasional headache, transient flushing at injection siteMild — injection site reactions, facial flushing, headache, dizziness
Synergy with other peptidesCommonly stacked with CJC-1295 or sermorelin (GHRH + GHRP synergy)Commonly stacked with ipamorelin or GHRP-2 for amplified GH pulse
Research depthModerate — multiple clinical studies on GH release and safetyExtensive — decades of clinical data, former FDA-approved drug
Approximate monthly cost$40–$80 (research grade); $150–$350 (clinic)$50–$100 (research grade); $200–$400 (clinic)

When to Choose Each

Choose Ipamorelin

Users who want clean GH elevation with minimal side effects, those sensitive to cortisol or prolactin increases, bodybuilders seeking lean mass gains without appetite disruption

Choose Sermorelin

Anti-aging clinic patients wanting a well-studied GH secretagogue, physician-supervised protocols, those who prefer a peptide with FDA-approval history

Verdict

Ipamorelin is the better choice for most users seeking clean, targeted GH elevation with minimal side effects — its selectivity means virtually no unwanted cortisol or prolactin spikes. Sermorelin is the better-studied option with a longer clinical track record and FDA history, making it preferred by physicians who want established safety data. The optimal approach for maximizing GH release is stacking ipamorelin with sermorelin (or CJC-1295), combining GHRP and GHRH pathways for a synergistic effect that can amplify GH output 3–5× beyond either peptide alone.

References

  1. Ipamorelin, the first selective growth hormone secretagogue (1998) — PubMed
  2. Growth hormone releasing peptides: clinical and basic aspects (1999) — PubMed
  3. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency (1999) — PubMed
  4. Safety and efficacy of ipamorelin for cardiovascular surgery patients (2008) — PubMed
  5. Growth hormone-releasing hormone and growth hormone secretagogues: therapeutic and diagnostic applications (2007) — PubMed

Frequently Asked Questions

Can I stack ipamorelin and sermorelin together?
Yes — this is one of the most popular GH peptide stacks. Ipamorelin (GHRP) and sermorelin (GHRH) act on different receptors, producing a synergistic GH release much greater than either alone. A typical protocol is 200 mcg ipamorelin + 200 mcg sermorelin injected subcutaneously together before bed, on an empty stomach.
Which peptide has fewer side effects?
Ipamorelin is considered the cleanest GH secretagogue available. Unlike other GHRPs (GHRP-2, GHRP-6, hexarelin), ipamorelin does not significantly raise cortisol or prolactin at standard doses. Sermorelin is also well-tolerated but may cause facial flushing and has a slightly broader hormonal impact.
How long before I see results from ipamorelin or sermorelin?
Most users report improved sleep quality within 1–2 weeks. Body composition changes (fat loss, lean mass) typically become noticeable at 4–8 weeks. Skin and recovery improvements often appear around 6–12 weeks. Consistent daily dosing and proper timing (before bed on an empty stomach) are critical for optimal results.
Why was sermorelin discontinued as an FDA-approved drug?
Sermorelin (brand name Geref) was discontinued for commercial reasons — not safety concerns. The manufacturer stopped production due to supply chain and business factors. Sermorelin itself remains available through compounding pharmacies and is widely prescribed in anti-aging medicine.
Which is more cost-effective, ipamorelin or sermorelin?
Both peptides are similarly priced at the research grade level, typically $40 to $100 per month. Clinic prices vary more widely, ranging from $150 to $400 per month depending on the provider and dosing protocol. Because ipamorelin and sermorelin are often stacked together for synergistic effects, many users budget for both rather than choosing one. Factors affecting overall cost include dosing frequency, concentration per vial, and whether a clinic consultation fee is included. Consulting a healthcare provider about the most appropriate and cost-effective protocol is advisable.

Explore next