Ipamorelin.
Clean GH secretagogue without hunger or cortisol effects A synthetic five-amino-acid peptide that switches on the ghrelin receptor in the pituitary, prompting a pulse of growth hormone. Studied by injection in research settings.
Reviewed March 2026
What Ipamorelin is, and what it does.
- Does it work
- It suits people working with a clinician inside a research or prescribing setting. Swallowed, it is broken apart by digestive proteases before it reaches the receptor.
- How much to take
- Research work sits around 100 to 200mcg a day by injection, and 300mcg is a study condition. This is a clinician-directed amount rather than a self-chosen one.
- Time to feel it
- Growth hormone rises within about an hour of a dose in research settings. Anything downstream runs through IGF-1 and shows on a blood panel over weeks, not as a sensation.
- The first dose
- In research settings a single dose produces a growth hormone pulse within roughly an hour that fades the same day. What is recorded is a hormone measure, not a feeling.
- With regular use
- Weeks out, the readout is IGF-1 on a blood panel. Long-run human data is scarce, and growth hormone raises liver glucose output, so glucose handling gets monitored alongside.
- How well tolerated
- Human tolerance data is limited and it is given by injection under medical supervision. Growth hormone lowers peripheral insulin sensitivity, so glucose is watched while it is used.
- How it feels
- The literature describes little of the hunger, cortisol or prolactin response seen with earlier agents of its class. Sleep reports exist but are anecdote, not a measured outcome.
- The overlooked benefit
- The axis self-limits. IGF-1 feeds back and shuts further release down, so more agonist does not produce more hormone. Secretion stays pulsatile by design rather than flat.
100 to 200mcg a day is where Ipamorelin works.
Source: Raun et al. Eur J Endocrinol 1998; growth hormone secretagogue research
The proof, claim by claim.
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
Ipamorelin has emerging evidence. Based on 112+ studies.
- Growth hormone secretionRandomised trial
- Selectivity over cortisol and prolactin releaseAnimal study
- Gastrointestinal motilityAnimal study
- Negligible oral bioavailability of the peptideNarrative review
Questions people ask about Ipamorelin.
- When should I take it?
- Timing matters less than consistency. Pick a time that works for you and take it daily.
- Can I take it with other supplements?
- Usually fine. The main thing to watch is not doubling up on the same ingredient from different products. If you're on prescription meds, check with your pharmacist first.
- Any side effects to watch for?
- Most people tolerate it well at recommended doses. GI upset is the most common complaint with any supplement. Start with a lower dose and work up. If something feels off, stop and reassess.
- Who benefits most from this?
- Honestly, most people would benefit more from the basics. But if you've got a specific reason to try it, the risk is generally low.
Why these belong in the same formula. Each row says what the basis is, from settled biochemistry through to a trial that measured the pair.
A ghrelin-receptor secretagogue triggers somatotroph release while arginine reduces the somatostatin signal that would damp it. Acting on the accelerator and the brake at once gives a larger pulse than either input on its own.
Ornithine converts to arginine through the urea cycle and so contributes to the same amino-acid signal that lowers somatostatin tone. It is a weaker version of the arginine interaction rather than a separate one.
Ipamorelin acts as an agonist at the ghrelin receptor on pituitary somatotrophs. Glycine has its own older literature on acute growth hormone release through a different route. Combining them is additive in theory only; no study has given the two together.
Oral GABA has been reported to raise circulating growth hormone acutely in small studies, likely through hypothalamic rather than pituitary receptor action. That would sit upstream of where a ghrelin receptor agonist acts. The pairing is speculative and the growth hormone reading is a hormone marker, not an outcome.
Growth hormone secretion is strongly pulsatile and concentrated in early slow-wave sleep. Anything that shifts sleep architecture therefore shifts the background against which a secretagogue acts. This is timing physiology rather than a demonstrated combination effect.
Low zinc status is associated with reduced circulating IGF-1 and blunted growth hormone signalling, and zinc is required for the structure of many transcription factors in that pathway. A secretagogue can only work against an adequately supplied axis. The relationship is nutritional rather than a pharmacological synergy.
Oral glutamine has been reported to raise growth hormone acutely in small studies. The mechanism is not the ghrelin receptor, so the routes differ from ipamorelin. Nothing has tested the combination and the readout in that literature is a hormone concentration.
Alpha-GPC supplies choline and has been studied for growth hormone responses around exercise, plausibly through cholinergic suppression of somatostatin tone. Somatostatin is the brake that a secretagogue has to work against. The interaction is mechanistically coherent and clinically untested together.
Lysine has been studied with arginine for acute growth hormone release, which is why it appears in the same formulation space as the stored arginine and ornithine rows. The mechanism is amino acid mediated and separate from ghrelin receptor agonism. Effects reported in that literature are small and inconsistent.
Growth hormone raises hepatic glucose output and reduces peripheral insulin sensitivity, while berberine acts in the opposite direction on glucose handling. Used together the two push against each other on the same measure. The point of flagging it is that a glucose reading may not reflect either ingredient alone.
Growth hormone and IGF-1 signalling drives protein synthesis only when amino acids are available to build with. A protein source supplies that substrate. This is a general nutritional dependency, not evidence of a combined effect with ipamorelin specifically.
Nothing specific on file for Ipamorelin. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.What Ipamorelin actually does.
Ipamorelin is a synthetic pentapeptide growth hormone secretagogue, sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2, acting as an agonist at the growth hormone secretagogue receptor GHS-R1a, the receptor whose endogenous ligand is ghrelin.
GHS-R1a agonism on pituitary somatotrophs raises intracellular calcium and triggers growth hormone release, and it also reduces somatostatin restraint at the hypothalamic level, which is why secretagogues act on a pulsatile rather than a flat secretion pattern.
Released growth hormone acts largely through hepatic IGF-1 production, and IGF-1 in turn feeds back to suppress further growth hormone release, so the axis self-limits rather than responding linearly to more agonist.
As a short peptide with ordinary amide bonds it is hydrolysed by gastric and pancreatic proteases, so oral bioavailability is negligible; the pharmacology described in the literature comes from parenteral administration in research settings.
Getting Ipamorelin from food.
The whole-food sources on file. A supplement closes the gap, it does not replace dinner.
A gram-for-gram figure (how much of each you would eat to match a dose) will appear here once it is sourced and reviewed. This page will not print a number it cannot cite.
The forms it comes in.
The studies, linked.
2 sources behind our Ipamorelin verdict: peer-reviewed studies and registered clinical trials. Every one links straight to PubMed, the journal, or ClinicalTrials.gov. Read them yourself.
- Clinical trialPhase II Double-Blind Placebo-Controlled Dose Finding Study to Evaluate Safety/Efficacy of Ipamorelin Compared to Placebo for Recovery of Gastrointestinal Function in Patients Following Small or Large Bowel Resection w/Primary AnastomosisClinicalTrials.gov ↗PHASE2 · 320 participants · Completed
- Clinical trialA Phase II, Double-Blind, Placebo-Controlled, Multiple-Dose Study to Evaluate the Safety and Efficacy of Ipamorelin Compared to Placebo for the Management of Post-Operative Ileus in PatientsClinicalTrials.gov ↗PHASE2 · 117 participants · Completed
Evidence surfaced via Semantic Scholar (Allen Institute for AI) and ClinicalTrials.gov. Ranked by study type and citation weight, not cherry-picked.
Problems people have reported.
Read this carefully. These are 43 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Ipamorelin is, not how risky it is. A report is not proof Ipamorelin caused anything. It is a signal of what to watch for, nothing more.
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.