Ipamorelin vs Sermorelin
One is a GHRP, one is a GHRH analog. Why are they compared, and why are they usually combined?
Reviewed by the amino101 editorial team. , first published .
Ipamorelin and sermorelin both make your pituitary release growth hormone, which is why clinics and vendors list them side by side, but they do it through different receptors. Sermorelin is the first 29 amino acids of growth hormone releasing hormone and acts on the GHRH receptor. Ipamorelin is a five amino acid GHRP that acts on the ghrelin receptor. The pituitary responds to both signals at once with a pulse larger than either produces alone, which is the whole basis of the GHRH plus GHRP stack. Sermorelin has the longer regulatory history: it was FDA approved as Geref until 2008 and has older human trials showing modest IGF-1 and lean mass changes in adults over 55. Ipamorelin completed phase 2 before Novo Nordisk dropped it, with human data limited to pilot GH release studies and one surgical recovery trial that missed its endpoint. Neither is approved today. Both are prohibited by WADA. This is an educational comparison, not a protocol.
| Ipamorelin | Sermorelin | |
|---|---|---|
| Typical dosage | 100 to 300 mcg | 200 to 500 mcg |
| Frequency | 1 to 3 times daily | once daily |
| Route | Subcutaneous | Subcutaneous |
| Half-life | about 2 hours in plasma | 10 to 20 minutes in plasma |
| Cycle | 8 to 16 weeks | 3 to 6 months |
| Research level | Well researched | Extensively studied |
| Human trials | Randomized trials | Approved drug |
| Status | Investigational, not FDA approved (Phase 2 trials completed, not pursued) | Formerly FDA approved (Geref, withdrawn 2008); widely available via compounding pharmacies |
| Effects timeline | deeper sleep 1 to 2 weeks, IGF-1 rise on bloodwork by 4 weeks, recovery and body composition 2 to 3 months | sleep quality 1 to 2 weeks, IGF-1 rise on bloodwork 4 to 6 weeks, body composition and skin 2 to 3 months if at all |
Key differences
Ipamorelin vs Sermorelin dosage
Dosage patterns reported in research and community protocols, by goal. Taken from each compound page. Not a prescription.
| Goal | Dosage | Frequency |
|---|---|---|
| Solo nightly dose | 200 to 300 mcg | once daily before bed |
| Stacked with a GHRH analog | 100 mcg | once daily before bed, with 100 mcg Mod GRF 1-29 |
| Three pulse protocol | 100 mcg | 3 times daily, on waking, after training, before bed |
| Recovery focus | 100 to 200 mcg | twice daily, after training and before bed |
| Goal | Dosage | Frequency |
|---|---|---|
| Clinic standard | 200 to 300 mcg | once daily before bed |
| Higher single dose | 500 mcg | once daily before bed |
| Stacked with a GHRP | 200 mcg | once daily before bed, with 100 mcg ipamorelin |
| 5 on 2 off variant | 300 mcg | once daily, weekdays only |
Convert any of these to syringe units in the dosage calculator.
Side effects compared
- ▲Headache, flushing, or lightheadedness shortly after a dose
- ▲Water retention and puffy hands at higher doses
- ▲Tingling in the fingers when stacked heavily
- ▲Mild appetite increase in some people
- ▲Injection site redness or itching
- ▲Injection site redness, itching, or small lumps
- ▲Flushing or warmth shortly after a dose
- ▲Headache or dizziness
- ▲Mild water retention
- ▲Drowsiness, which is why bedtime dosing is preferred
Which should you choose?
Ipamorelin is the better fit for a self directed protocol where the goal is a clean nightly GH pulse with minimal side effects. Its 2 hour half-life and selectivity mean no cortisol or prolactin rise and little hunger. It is also the GHRP you would pair with a GHRH analog, so buying it first keeps the stack option open. People on GLP-1 drugs sometimes add it hoping to protect lean mass, though no human trial shows that; see GLP-1 muscle loss.
Sermorelin is the better fit if you want the compound with the longest human track record, if a clinic is prescribing it, or if you are new to secretagogues and want the gentlest option. It was an approved drug, its trials in adults over 55 showed modest IGF-1 and lean mass gains, and 200 to 300 mcg nightly is the common clinic dose. Expect a smaller pulse than from the stabilized GHRH analogs.
If you have to pick one, pick by what you are buying it for. Sermorelin is the choice if you are going through a clinic that will only prescribe a compound with a regulatory history, or if you want the gentlest possible GH secretagogue with older but real human data. Ipamorelin is the choice for a self directed protocol because its pulse is cleaner, its half-life is longer, and it does not raise cortisol or hunger. But most people who understand the pharmacology do not pick. A GHRH analog and a GHRP together produce a pulse several times larger than either alone, and the common clinic version of that is 200 mcg sermorelin with 100 mcg ipamorelin in one syringe before bed. The self directed version swaps sermorelin for Mod GRF 1-29, which is the same idea with a more stable molecule, and is covered in the CJC-1295 and ipamorelin stack.
Stacking: Commonly combined in one syringe before bed on an empty stomach. Sermorelin 200 mcg with ipamorelin 100 mcg is the clinic pattern; many self directed users replace sermorelin with Mod GRF 1-29.
Ipamorelin is a pentapeptide that triggers growth hormone release through the ghrelin receptor without the cortisol, prolactin, or hunger spikes seen with older GHRPs. It is the most popular GHRP in the community, usually stacked with a GHRH analog.
Sermorelin is the first 29 amino acids of natural growth hormone releasing hormone, the shortest fragment that still fully activates the receptor. It was once an approved diagnostic and pediatric drug and is now the most common growth hormone secretagogue prescribed by anti-aging and wellness clinics.
Ipamorelin vs Sermorelin: frequently asked
Can you take ipamorelin and sermorelin together?
Yes, and that is the most common way clinics use them. They act on different receptors, so the pituitary gets two signals at once and the resulting pulse is larger than either alone. The usual pattern is both in one syringe before bed on an empty stomach, with 200 mcg sermorelin and 100 mcg ipamorelin as a reported clinic dose.
Which is better for fat loss, ipamorelin or sermorelin?
Neither has human fat loss data of its own. Both work by raising GH and IGF-1, which increases lipolysis, and the effect is modest. If fat loss is the main goal, tesamorelin is the GHRH analog with actual visceral fat trials, and the GLP-1 drugs are in a different league.
Which is better for sleep, ipamorelin or sermorelin?
Both are injected at bedtime and both produce reports of deeper sleep within 1 to 2 weeks. Ipamorelin is cited more often, partly because its longer half-life gives a more reliable pulse. Sermorelin's drowsiness side effect is the reason it is dosed at night in the first place. Neither has a sleep trial.
Is sermorelin or ipamorelin FDA approved?
Sermorelin was, as Geref, from 1997 until the manufacturer withdrew it in 2008 for commercial reasons. It is now available only through compounding pharmacies. Ipamorelin was never approved; Novo Nordisk completed phase 2 and stopped. Both are prohibited by WADA.
What is the difference between a GHRP and a GHRH analog?
A GHRH analog like sermorelin mimics the hypothalamic hormone that tells the pituitary to release GH. A GHRP like ipamorelin mimics ghrelin, the stomach hormone that does the same thing through a different receptor and also reduces somatostatin, the brake on GH. Because they use different pathways, combining them is synergistic rather than additive.
Related reading
Pulsatile growth hormone release
Visceral fat loss with growth hormone support
Weight loss while limiting muscle loss
The two halves of the most popular GH stack. What does each one do, and which CJC-1295 are you actually buying?
An approved GHRH analog with fat loss trials versus the community's favorite GHRP.
Two GHRH analogs with approval histories. Which one still earns the price?
Sources
- Effects of nightly GHRH 1-29 administration in healthy older men and women. Journal of Clinical Endocrinology and Metabolism, 1997
- Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 1998