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Muscle & performanceAnti-aging & longevity

Ipamorelin

NNC 26-0161 · GHRP

Early human trialsProhibited in sportReviewed 12 Aug 2026

Ipamorelin is a five-amino-acid peptide that acts on the ghrelin receptor to trigger release of growth hormone from the pituitary. Its selling point relative to older secretagogues is selectivity: earlier compounds in this family also raised cortisol and prolactin, and ipamorelin was developed to avoid that.

It has been the subject of early pharmacological work showing it does what it says: a measurable GH pulse without the hormonal spillover. What does not exist is the next step. No trial has established that the resulting GH pulses produce meaningful changes in body composition, recovery or anything else in healthy adults, and it has never been approved for any indication.

So the honest summary is unusual: the mechanism is reasonably well demonstrated, and the outcomes are not studied at all. Those are different claims, and most writing about ipamorelin runs them together.

How it works

The pituitary releases growth hormone in pulses, under opposing control from GHRH (which promotes release) and somatostatin (which suppresses it). Ipamorelin acts at a third input — the ghrelin receptor — which both stimulates release and briefly dampens somatostatin.

Because it works with the body's existing pulsatile pattern rather than replacing it, the resulting GH profile looks more like natural secretion than injecting growth hormone does. That is the mechanistic argument for this class, and it is a reasonable one. On its own it is not evidence of benefit.

The pulse is short. GH rises within minutes and returns toward baseline within a couple of hours. That is why protocols describe multiple daily doses rather than one.

Regulatory status — United States

Not approved for human use in the United States for any indication. The FDA has identified ipamorelin as a substance raising concerns for use in compounded preparations. Material sold online is a research chemical.

Last reviewed 12 Aug 2026. Regulatory positions in this category change frequently; we date this line so you can see how current it is.

What it is studied for

Each entry states the evidence behind it. We do not rank indications by effectiveness — for most compounds here, that would be a claim nobody can support.

Growth hormone release

Published review

The one thing genuinely demonstrated: it produces a measurable GH pulse.

EvidenceEarly human pharmacology showing GH release without meaningful cortisol or prolactin rise. These measured hormone levels, not outcomes.

Body composition and recovery

Community practice

The reason most people are interested, and the part with no evidence behind it.

EvidenceNo controlled trial has measured body composition, strength or recovery outcomes in healthy adults.

Identity and clearance

Molecule

Class
Pentapeptide, ghrelin receptor agonist
Molecular weight
711.86 Da
Length
5 amino acids

Sequence

Aib-His-D-2-Nal-D-Phe-Lys-NH2

Contains non-standard residues. Which is what gives it stability and receptor selectivity that a plain five-amino-acid chain would not have.

Pharmacokinetics

Published review
Peak0.5 h
Half-life2 h
Substantially cleared10 h
100%50%25%0%half-life 2hdose3h5h8h10h
Modelled from the half-life above, assuming first-order elimination. Illustrative rather than measured — it shows the shape of clearance, not a prediction for any individual.

The GH pulse itself is shorter than the compound's own clearance. Hormone levels return toward baseline before the peptide has fully gone.

Dose protocols reported in sources

Displayed for reference only. Every row says where it came from, and a trial protocol and a community convention are not the same kind of information. None of this is fed into the calculator, and none of it is a recommendation.

Dose protocols reported in sources, with the source of each.
GoalDoseFrequencyRouteUnits, 2 mg vialSourceStart this protocol
Commonly described dose200 mcg – 300 mcgOne to three times dailySubcutaneous10–15 uCommunity practiceStart this
Before bed, commonly described200 mcg – 300 mcgOnce daily at nightSubcutaneousTimed to coincide with the body's largest natural GH pulse during early sleep. The reasoning is sound; it has not been tested against other timings.10–15 uCommunity practiceStart this

Start this copies a row into a protocol of your own, which you can then edit. Where a source gave a dose range or an ambiguous frequency, those fields arrive empty — we will not pick a number on your behalf.

CheckRows marked community practice describe what people commonly do, drawn from public discussion. They are not derived from any trial and are not evidence that a dose is safe or effective.

Cycling

Community practice

8 to 12 weeks on, 4 weeks off.

Receptor desensitisation is the usual stated reason for cycling. No study establishes at what point, or whether, that occurs at these doses.

Calculator

Work out what to draw

Pre-filled with a 5 mg vial as a worked example. These are not recommended values — change them to match the vial in front of you.

Dose unit
Your syringe
010203040506070809010010 units0.1 mL

Draw to 10 units on a 1 mL U-100 syringe. That is 0.1 mL, containing 250 mcg of Ipamorelin.

Concentration2.5mg / mL
Volume drawn0.1mL
Doses per vial20doses
Per unit25mcg / unit

10 units sits exactly on a printed line.

Bioalmanac performs arithmetic on values you enter. It does not recommend doses, schedules or compounds, and nothing here is medical advice. Confirm every calculation against your vial and syringe before drawing, and speak with a licensed healthcare provider.

Open this calculation in the full calculator

Units, concentration, bacteriostatic water — the glossary defines the vocabulary, and a unit is not a fixed volume.

Safety

Reported effects

  • Flushing or head rush shortly after injectionCommunity practice

    Commonly reported

    Usually brief, within the first few minutes.

  • Increased hungerCommunity practice

    Commonly reported

    Expected from the mechanism. This acts on the ghrelin receptor, and ghrelin is the hunger hormone.

  • Water retention, tingling or numbness in the handsCommunity practice

    Occasionally reported

    Classic growth-hormone-related effects. Carpal tunnel symptoms are a recognised consequence of raised GH.

  • Headache or lethargyCommunity practice

    Occasionally reported

  • Effects of sustained GH elevationCommunity practice

    Unknown

    Long-term consequences of repeatedly raising GH in people who are not deficient have not been studied.

When to stop

  • Numbness, tingling or pain in the hands or wrists that persists. This can indicate fluid-related nerve compression.
  • Noticeable swelling in the hands, feet or face.
  • Symptoms suggesting raised blood sugar: unusual thirst, frequent urination, or blurred vision. Growth hormone opposes insulin.
  • Any new lump or growth. Growth hormone and IGF-1 promote cell proliferation, so this warrants prompt investigation rather than watching.
  • Signs of infection at an injection site, or any allergic response. Seek urgent care for the latter.

Interactions and situations that need care

  • Active or previous cancerAvoid

    Growth hormone raises IGF-1, which promotes cell growth and survival. That is the intended effect in tissue and an unwanted one in a tumour. Growth hormone therapy is contraindicated in active malignancy for this reason, and a compound that raises GH deliberately falls under the same logic.

  • Diabetes or impaired glucose toleranceUse caution

    Growth hormone opposes insulin and raises blood glucose. Someone managing blood sugar is adding a variable that works against their treatment, and no study has quantified the effect at these doses.

  • Pregnancy and breastfeedingAvoid

    No reproductive or developmental safety data exists.

  • Competing in a tested sportAvoid

    Growth hormone secretagogues are explicitly prohibited at all times under WADA's S2 category.

  • Children and adolescentsAvoid

    Growth hormone axis manipulation during growth has consequences no self-directed protocol can manage. Genuine GH deficiency in children is treated under specialist supervision for good reason.

SportProhibited by the World Anti-Doping Agency under S2: Peptide Hormones, Growth Factors and Related Substances, at all times. Growth hormone secretagogues are explicitly named in S2.

What to expect

HonestlyThere is no human efficacy data for this compound, so there is no evidence-based timeline to give. Any site publishing a week-by-week schedule of expected effects has invented it.

  • The GH pulse is real and measurable. Whether that pulse produces any outcome you would notice is the part nobody has studied.
  • Increased hunger is the most consistently reported effect, and it follows directly from the mechanism rather than being incidental.
  • Growth hormone effects on tissue, where they occur at all, develop over months rather than weeks.
  • Anyone quoting body composition figures for ipamorelin is extrapolating from growth hormone research, not citing research on ipamorelin.

Storage and handling

Freeze-dried powder
Refrigerated at 2–8 °C, protected from light.
After mixing
Refrigerated at 2–8 °C. Do not freeze once mixed.
Long-term, frozen
Unopened powder is stable at −20 °C or colder.

Printable one-pagerHow to reconstitute a vial, step by step

With other peptides

  • The argument for a secretagogue is that it preserves pulsatile release. Adding exogenous growth hormone discards that argument and doubles the exposure.

  • CJC-1295synergistic

    The most commonly discussed pairing in this category: a GHRH analogue and a ghrelin receptor agonist act on different inputs to the same pituitary output, so the combined pulse is larger than either alone. The mechanism is well described; outcome evidence for the combination is not.

  • MK-677caution

    Both act on the ghrelin receptor. Combining them stacks one mechanism rather than adding another, and compounds the hunger and water retention.

  • Sermorelinsynergistic

    The same two-input logic as CJC-1295 with ipamorelin: a GHRH analogue alongside a ghrelin receptor agonist. Sermorelin's shorter half-life means the combined pulse is briefer.

  • GHRP-2caution

    Both are ghrelin receptor agonists, so their growth hormone effects overlap rather than add. Ipamorelin is usually chosen over GHRP-2 precisely to avoid the prolactin and cortisol rise, and running both discards that advantage.

  • GHRP-6caution

    Same receptor, overlapping effects. Ipamorelin exists to avoid GHRP-6's hunger, prolactin and cortisol effects, and combining them gives those back.

  • Hexarelincaution

    Both are ghrelin receptor agonists. Ipamorelin's selling point is selectivity, and pairing it with the least selective compound in the class removes the reason to have chosen it.

Check this against a whole stack

In use

Stacks with Ipamorelin in them

Documented combinations, with full schedules.

Checking your vial

Research chemicals carry no manufacturing standard, so what the vial looks like is often the only quality signal available before you use it. More on assessing quality and COAs.

  • White cake, clear solution

    Standard for a correctly lyophilised short peptide.

  • Collapsed cake or cloudy solution

    Indicates heat damage in transit or degraded material.

Questions

Why is ipamorelin described as more selective than other GHRPs?
Earlier compounds in this family raised cortisol and prolactin alongside growth hormone. Ipamorelin was developed to trigger GH release without that spillover, and early human pharmacology supports that claim specifically.
Why do protocols describe several doses a day?
The GH pulse it produces is short. Hormone levels rise within minutes and fall back within a couple of hours. Multiple daily doses are an attempt to reproduce more than one pulse, not a dose-escalation strategy.
Does it matter that it makes you hungry?
It depends entirely on your goal. The hunger comes from acting on the ghrelin receptor, which is the same receptor that signals hunger. It is inseparable from the mechanism, not a side effect that might one day be engineered out.

References

  1. Growth hormone secretagogues: history, mechanism of action and clinical development

    JCSM Rapid Communications / review literature, 2018 · Review

    Humans and animal models

    Reviews the ghrelin receptor secretagogue class, including selectivity differences between compounds and the short duration of the GH pulse each produces.

  2. Commonly reported community protocols

    Bioalmanac editorial summary of public community sources, 2026 · Not a study

    Summarises the dose ranges, timing conventions and cycle lengths most consistently described in public discussion. Carries no evidential weight about safety or effect.

Keep this page honest

If something here is wrong, out of date, or missing a source, tell us and we will fix it and say that we did.

Suggest a correction

This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice. No clinician reviews these pages.

Page last updated 12 Aug 2026