Ipamorelin

What is Ipamorelin?

A selective five-amino-acid growth hormone secretagogue that prompts your pituitary to release GH without raising cortisol or prolactin — and isn't FDA-approved.

Ipamorelin is a peptide, a short chain of amino acids, the same building blocks that make up every protein in your body. The version people buy is five amino acids long, with the sequence Aib-His-D-2-Nal-D-Phe-Lys. Two of those, aminoisobutyric acid and D-2-naphthylalanine, aren't standard amino acids, which is part of what makes the molecule more stable than the peptides it came from.

It belongs to a class called growth hormone secretagogues. Rather than being growth hormone, it acts on the ghrelin receptor in the pituitary gland and signals it to release a pulse of your own GH. Novo Nordisk built it in the mid-1990s, under the code NNC 26-0161, while searching for a cleaner version of earlier compounds like GHRP-6 and GHRP-2.

What set it apart in those early studies was selectivity. It triggered growth hormone release without measurably raising cortisol, prolactin, or ACTH, even at doses far above the threshold for a GH response. The older peptides in its class don't manage that, which is why Ipamorelin is often described as the first truly selective member of the group.

What is it studied for?

The human record is thin and negative: its one real clinical trial, for bowel recovery after surgery, didn't beat placebo, so claims rest on mechanism and animals.

The human record here is thin and mostly negative. Novo Nordisk ran early-phase safety and pharmacokinetic work, and Helsinn Therapeutics later took it into a Phase 2 trial for postoperative ileus, the slow return of bowel function after surgery. That trial didn't show enough benefit over placebo, and clinical development stopped. So the body-composition and recovery claims attached to it today rest on its mechanism and on animal work, not on positive human efficacy data.

What's drawn interest clusters in a few areas:

The mechanism is the part that's actually well characterized. Ipamorelin binds the ghrelin receptor on the pituitary and provokes a GH pulse while leaving cortisol and prolactin largely untouched, and it tends to preserve the natural pulsing rhythm of GH rather than flattening it into a constant elevation. What's genuinely open is whether that clean pituitary signal translates into the body-composition and recovery outcomes people want, since the trial that tested a real clinical endpoint came up short.

Why people use it

People use it for body composition, sleep, and recovery — often stacked with CJC-1295 — but no human trial shows it improves any of those.

Most people who try Ipamorelin land in one of a few situations. These are the reasons they reach for it, not evidence that it delivers:

• Wanting the effects associated with higher growth hormone, lean mass, fat loss, recovery, without injecting GH itself, on the logic that prompting your own pulse is gentler than replacing it.
• The selectivity story: choosing it over older secretagogues specifically because it's reported not to spike cortisol or prolactin.
• Stacking it with CJC-1295, a GHRH analog, so one peptide tells the pituitary to release while the other raises how much it has ready, a pairing people treat as a single GH protocol.
• Better sleep and next-day recovery, with the dose timed to the body's own nighttime GH surge.

How to reconstitute Ipamorelin

A 5 mg vial in 2 mL gives 2.5 mg/mL, so 10 units on a U-100 syringe is 250 mcg; swirl gently, never shake.

Your vial arrives as a small puck of dry powder. Before you can use it, you mix it into a liquid. That step is called reconstitution, and it's the same process used for most research peptides.

• Wipe the rubber stopper with an alcohol swab first, every time.
• Use bacteriostatic water, not plain sterile water and not saline. The trace of benzyl alcohol in it holds back bacteria, which matters because you'll be drawing from the same vial for weeks.
• Add the water slowly, running it down the inside glass wall. Don't blast it straight onto the powder.
• Don't shake it. Swirl gently and let it dissolve on its own. Shaking foams the solution and can damage the peptide.

A common setup is a 5 mg vial mixed with 2 mL of bacteriostatic water, which gives 2.5 mg/mL. On a U-100 insulin syringe, 10 units is then 250 mcg. The water doesn't change how much peptide is in the vial; it only sets the concentration, which decides how many units you draw. More water means a more dilute mix and a bigger draw for the same dose. You can't ruin it with too much or too little, you only change the draw math, and that's exactly what the calculator handles.

Dose & units

No FDA-approved dose exists; write-ups report 100–300 mcg per dose, usually 30–45 minutes before bed, run roughly 12 weeks on then off.

Typical range

Injected under the skin, the range reported most often is 100–300 mcg per dose, with beginners near 100 mcg and more experienced users toward 200–300. (A microgram, or mcg, is a thousandth of a milligram.) Some protocols run it once a day, others two or three times.

Timing

The dose is usually placed 30 to 45 minutes before bed on a relatively empty stomach. Two reasons get cited: it lines up with the body's own GH surge during deep sleep, and low food and insulin at that moment let the pulse come through instead of being blunted.

Cycling

Write-ups treat this as a course rather than something you run forever, commonly around 12 weeks on followed by several weeks off, partly to limit receptor desensitization. The exact split varies source to source, which itself tells you how soft these numbers are. Starting nearer the low end lets you notice any reaction before you've committed to more.

For the exact mark to draw to on your insulin syringe, don't eyeball it. The calculator turns your vial size, water, and dose into the precise number of units.

Storage

Dry powder keeps for months at room temperature; once mixed, refrigerate at 2–8 °C and use within about 4 weeks before contamination becomes the limit.

That four-week limit is about contamination, not potency, since the peptide itself often stays good well beyond it. Reconstitute with plain sterile water instead of bacteriostatic and you drop to a day or two, since there's no preservative holding bacteria back.

Don't freeze a reconstituted vial, keep it out of direct light, write the mix date on the label, and throw it out if the solution ever turns cloudy or discolored, whatever the date says.

Side effects & safety

Reported effects are mild (injection-site flush, headache, hunger), but it's WADA-banned at all times under S2, and cancer or diabetes warrants caution.

The reported side effects are generally mild. That picture comes from early-phase safety work, animal studies, and scattered user reports, not large human safety trials, so hold it loosely.

• Most common: mild, short-lived redness or irritation at the injection site, and a flush or warmth right after dosing.
• Less often: headache, light dizziness, water retention, or a brief rise in hunger, which tracks with its action on the ghrelin receptor.
• Over a longer course, the GH and IGF-1 it raises can in principle affect insulin sensitivity and blood sugar, worth watching if that's already a concern for you.

If you compete, Ipamorelin is banned. It sits under category S2 of the WADA Prohibited List as a growth hormone secretagogue, prohibited at all times, both in and out of competition. Anti-doping labs have validated tests for the metabolites of these peptides in urine, and athletes in major leagues have tested positive. A positive test is a doping violation.

And the biggest risk here isn't really the molecule. It's whether what's in the vial is actually Ipamorelin, at the strength on the label. That comes down to where you buy it.

How to vet a source

Often sold pre-blended with CJC-1295, so two peptides and their ratio are unseeable in powder — demand a batch-specific third-party COA matching your lot.

This is an unregulated market, and a real share of independently tested vials come back underdosed, impure, or not even the compound on the label. With Ipamorelin there's an added wrinkle: it's frequently sold pre-blended with CJC-1295, so you're trusting a seller to get two peptides and their ratio right, and you can't see any of that in the powder. Where you buy matters more than almost anything else here. The one document that separates a real seller from a gamble is a certificate of analysis: a third-party lab's report on what's actually in the vial.

That's the standard worth holding any seller to, ours included. Ask for the batch-specific COA before you buy, match the lot number to your vial, and don't accept a screenshot in place of a traceable report.

Common questions about Ipamorelin

References

1. Ipamorelin — Wikipedia (sequence, NNC 26-0161, Novo Nordisk, Helsinn Phase 2 ileus trial, doping status, athlete cases)
2. Raun et al. — Ipamorelin, the first selective growth hormone secretagogue (European Journal of Endocrinology, 1998)
3. Beck et al. — Ghrelin mimetic ipamorelin for postoperative ileus in bowel resection patients, proof-of-concept RCT (Int J Colorectal Dis, 2014; NCT01280344)
4. FDA — Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks (503A Category 2 list)
5. Lexology — FDA removes certain peptide bulk drug substances (including ipamorelin) from Category 2 of the interim 503A bulks list and sets PCAC review dates (Sept 2024)
6. WADA — Prohibited List, Section S2 (peptide hormones, growth factors and mimetics; GH secretagogues)
7. Drugs.com — WADA S2: Peptide Hormones, Growth Factors and Related Substances
8. Sinha et al. — Growth hormone secretagogues in body composition management (Translational Andrology and Urology, 2020)
9. The GH Secretagogue Receptor: Intracellular Signaling and Regulation (PMC3975427)
10. Ipamorelin — ChemicalBook (CAS 170851-70-4, formula C38H49N9O5, MW 711.85)