NOT FDA-APPROVED

Ipamorelin

The supporting actor · usually stacked, not used alone

Almost never used solo. Ipamorelin is the supporting actor in modern GH-stack protocols, paired with CJC-1295 or Tesamorelin to produce a synergistic GH pulse 2 to 3 times higher than either peptide alone. Its selectivity (no cortisol, prolactin, or appetite spikes of older GHRPs) is what makes it the GHRP of choice in those stacks.

The 30-second read

Ipamorelin is a small synthetic five-amino-acid peptide that activates the ghrelin receptor (GHS-R) in the pituitary gland, triggering a pulse of natural growth hormone release. What sets it apart from older GH-releasing peptides like GHRP-2 and GHRP-6 is selectivity: it raises GH without significantly raising cortisol, prolactin, or appetite. That clean profile is why it's the GHRP most often used in research-peptide protocols today, almost always paired with a GHRH analog like CJC-1295 for synergistic effect. Not FDA-approved. On the FDA's Category 2 list as of September 2023. The full GH-stack story lives on the combo page.

Almost always used as part of a stack: in research, Ipamorelin is paired with CJC-1295 to produce a synergistic GH pulse 2 to 3 times higher than either alone. The combination story, mechanism, dosing, the DAC-version Phase 2 history, lives on the dedicated CJC-1295 / Ipamorelin combo page.

Why this peptide is on people's radar

Ipamorelin's appeal comes from its design: the cleanest selectivity profile of any synthetic ghrelin-receptor agonist available. The older generation of GH-releasing peptides. GHRP-2, GHRP-6, hexarelin, all worked, but they came with collateral effects. GHRP-6 cranked up appetite (often the point in some protocols, but a problem in others). GHRP-2 raised cortisol meaningfully. Hexarelin elevated prolactin. Researchers wanted a GH secretagogue without those side-channels, and Ipamorelin came out of Novo Nordisk's screening program in the 1990s as the answer.

The selectivity is what made Ipamorelin the dominant GHRP in modern peptide-research circles. People in their 30s, 40s, and 50s using it for sleep, body composition, or recovery don't generally want appetite swings, cortisol spikes, or prolactin issues. Ipamorelin gives them the GH-stimulation effect with a much cleaner side-effect profile.

In practice, Ipamorelin is almost never used alone. The standard research-community approach is to pair it with a GHRH analog, usually CJC-1295 (No DAC), to produce a synergistic GH pulse that's 2 to 3 times higher than either peptide alone. That's the combo most people end up actually using. Full combo explainer →

What people are usually trying to do with it

People exploring Ipamorelin (usually as part of a stack) are typically focused on:

  • A clean GH bump without cortisol or appetite side effects
  • Better sleep, especially the slow-wave phase that GH pulses through
  • Recovery support that's gentler than direct GH
  • Holding lean body composition into adulthood
  • Adding a GH-axis option to a longevity or recovery protocol
  • An alternative to older GHRPs (GHRP-2, GHRP-6) with cleaner side effects

What the science actually shows

The pharmacokinetic and selectivity story is well-characterized. The downstream-outcomes story in healthy adults is much thinner. Plain-English summary:

GH release without cortisol or prolactin elevation

The signature finding, multiple studies show Ipamorelin produces a GH pulse comparable to other GHRPs while leaving cortisol, prolactin, and ACTH essentially unchanged at therapeutic doses.12

Synergy with GHRH analogs

Pharmacokinetic studies show that combining Ipamorelin with a GHRH analog (CJC-1295, sermorelin) produces 2 to 3 times higher GH levels than either alone, the basis of the dominant research-community stack.3

Bone growth and recovery (preclinical)

Animal models report improvements in bone growth markers, muscle recovery, and connective tissue repair with Ipamorelin treatment, consistent with downstream IGF-1 effects of elevated GH.4

Modest IGF-1 elevation

Studies of Ipamorelin (alone or stacked) report measurable IGF-1 elevation over weeks of treatment, the downstream marker most often tracked as a proxy for GH activity.5

What hasn't been demonstrated

That Ipamorelin reliably produces sleep, body composition, or recovery outcomes in healthy adults. Long-term safety with continuous nightly use. Direct head-to-head comparisons with conventional GH replacement at similar IGF-1 levels.

The honest read

What's solid:

The selectivity profile is the strongest part. Ipamorelin really does produce GH release without raising cortisol or prolactin, and that distinguishes it cleanly from older GHRPs. The synergy with GHRH analogs in pharmacokinetic studies is well-replicated. The mechanism is coherent.

What's still unproven:

Whether the cleaner GH elevation reliably produces the downstream outcomes (sleep, body composition, recovery, anti-aging effects) people use it for. Most of those claims rest on anecdote and on extrapolation from synthetic-GH research, which has a different pharmacology. Long-term safety in healthy adults with chronic nightly use is uncharacterized.

What's hyped beyond the evidence:

Bold claims about anti-aging, dramatic body recomposition, or "feeling 25 again" from Ipamorelin specifically. The clean side-effect profile is real and meaningful; the dramatic-results story is much less supported. Also worth knowing: the closely related CJC-1295-with-DAC (the long-acting variant of the GHRH partner) had its Phase 2 development halted for adverse events. That's not a knock on Ipamorelin specifically, but it is part of the honest picture for the GH-modulating-peptide class.

Things to know if you're looking into it

  • Almost always stacked: the dominant research-community use is Ipamorelin paired with CJC-1295 (No DAC). The combo page covers the synergy and dosing in detail. Combo page →
  • How it's used in research: typically a small subcutaneous injection at night before bed, on an empty stomach, to align with natural slow-wave-sleep GH pulses.
  • Selectivity advantage: Ipamorelin doesn't significantly raise cortisol, prolactin, or appetite at typical doses. That's the main reason it's preferred over older GHRPs.
  • Athlete bans: Ipamorelin is on the World Anti-Doping Agency banned list and most professional and collegiate sports prohibited-substance lists.
  • Regulatory status: not FDA-approved. On the FDA Category 2 list as of September 2023, making compounding-pharmacy access legally restricted.
  • Caution populations: avoid in active malignancy (theoretical concerns about GH/IGF-1 effects on tumor biology). Use cautiously with diabetes, sleep apnea, or carpal tunnel syndrome.
  • Specific dosing protocols, mechanism, and the full reference list: all in the "Want to go deeper?" section below, with the combo-stack details on the dedicated combo page.

Reconstitution & dose calculator

Not FDA-approved. On the FDA Category 2 list as of September 2023. The dose math below covers Ipamorelin used solo. Most research-community protocols stack it with CJC-1295 — the per-injection dose stays the same, the calculator just doesn't model the GHRH partner. Athletes: Ipamorelin is on the WADA and most pro/collegiate banned-substance lists. This is an educational reference, not dosing guidance.
Suggested start
100 mcg/inj
Conservative entry; assess tolerance
Common range
100–300 mcg/inj
200 mcg is the typical working dose
Max dose
500 mcg/inj
GH receptors saturate above this
Cycle
8–12 wks on
Then 4–8 weeks off
mL
Defaults to a 5 mg/mL dilution — standard 200 mcg dose lands at 4 units, 300 mcg at 6 units. If you'd rather work at larger draw volumes, reconstitute with 4 mL water (2.5 mg/mL) and the units roughly double.
mcg
Subcutaneous injection. Most research protocols dose once at bedtime on an empty stomach to align with natural slow-wave-sleep GH pulses; some run 2–3× daily for stronger stimulus — the duration estimate below assumes once daily.
Concentration
5.0 mg/mL
Per dose
0.04 mL
4 units on insulin syringe
Doses per vial
~50
~50 days (~7.1 weeks) of daily dosing

When to stay put vs. adjust

Stay put at 200 mcg before bed when sleep quality is improving (deeper, more vivid dreams are commonly reported as the GH pulse takes hold), when there's no morning grogginess or water retention, and when you're not yet at the cycle's end. The bedtime timing matters because endogenous GH pulses concentrate in slow-wave sleep — injecting then layers your dose onto the body's natural rhythm rather than fighting it.

Consider adding a second daily dose (morning, fasted) rather than increasing the per-injection amount, if you want a stronger GH signal. Two 200 mcg pulses produce more total GH exposure than one 400 mcg pulse because the receptors saturate — pulse frequency moves the needle, single-dose magnitude doesn't, past about 300 mcg.

Watch for water retention, joint discomfort, mild carpal-tunnel-style tingling, or elevated fasting glucose. These are downstream of GH/IGF-1 elevation and tend to scale with cumulative dose. Drop the per-injection amount or frequency by one step if any appear; they usually resolve within a week.

Don't go above 500 mcg per dose. GH-secretagogue receptors saturate around this point — more peptide doesn't produce more GH, it just produces more peptide in circulation. The "more is better" reflex from titratable drugs doesn't apply to a pulsatile system.

Empty stomach matters. Elevated insulin or glucose suppresses GH release. Inject at least 60–90 minutes after the last meal (and 30+ minutes before the next one) for the cleanest pulse. This is one of the few protocol details that's well-supported by GH physiology rather than community wisdom.

Cycle off at the 8–12 week mark for 4–8 weeks. Continuous chronic GH-axis stimulation hasn't been characterized in healthy adults, and the off-cycle gives the system time to reset baseline sensitivity.

The honest read. The selectivity profile (no cortisol or prolactin elevation) is real and meaningful — it's why Ipamorelin is the GHRP of choice. The downstream outcome data (sleep, body composition, recovery) in healthy adults is much weaker. Most enthusiasm comes from the cleaner side-effect profile and from extrapolation from synthetic-GH research, which has different pharmacology. Almost everyone who actually uses this stacks it with CJC-1295; see the combo page for that protocol.

For educational and research purposes only. This is not medical advice. Ipamorelin is not FDA-approved, is on the FDA Category 2 list, and is on WADA and most pro/collegiate sports prohibited-substance lists. Avoid in active malignancy; use cautiously with diabetes, sleep apnea, or carpal tunnel syndrome. Consult a licensed healthcare provider before any health decision.

What people often ask

Should I use Ipamorelin alone or with CJC-1295?

The dominant research-community approach is to combine them. Used alone, Ipamorelin produces a smaller GH pulse than the combination. Most people who care enough to use Ipamorelin care enough to want the synergy. Talk to a clinician about which approach makes sense.

Will it raise my cortisol or prolactin?

At typical research-community doses, no, that's Ipamorelin's signature feature. Older GHRPs (GHRP-2, GHRP-6) do raise cortisol and prolactin meaningfully; Ipamorelin doesn't, and that's much of why it's preferred.

How does it compare to direct HGH?

Different pharmacology. Synthetic GH produces a sustained, non-physiologic elevation. Ipamorelin (especially combined with a GHRH analog) produces a brief pulse that more closely resembles the body's natural pattern. Whether the pulsatile approach is "better" in the long run hasn't been rigorously characterized.

Is it FDA-approved?

No. Ipamorelin is not FDA-approved for any indication. It was added to the FDA's Category 2 list in September 2023, making it ineligible for compounding by licensed pharmacies under standard pathways.

Are there side effects?

Reported side effects in research-community use are uncommon and generally mild, mild flushing, occasional injection-site reactions, sometimes a brief lightheaded feeling. The signature feature is the absence of side effects associated with older GHRPs.

Will I test positive on a drug test?

Yes. Ipamorelin is on the WADA banned list. Competitive athletes will test positive.

Why do people inject it at night?

The body's natural GH pulses are largest during early slow-wave sleep. Bedtime dosing aligns the secretagogue's pulse with the body's natural rhythm rather than disrupting it.

FDA and regulatory status

Status as of May 5, 2026: Not FDA-approved for any medical indication. Added to the FDA's Category 2 list in September 2023, making it ineligible for compounding by licensed pharmacies under Sections 503A and 503B. The April 2026 FDA advisory-committee review of seven compounded peptides did not include Ipamorelin in scope. Status updates land here when they happen.

Want to go deeper? Mechanism, half-life, dosing, side-effect profile, and references. The synergy with CJC-1295 is on the dedicated combo page.

Background

Ipamorelin (Aib-His-D-2Nal-D-Phe-Lys-NH₂) is a synthetic pentapeptide (five amino acids) developed by Novo Nordisk in the late 1990s. It was designed to act selectively on the ghrelin receptor (GHS-R1a) without engaging the side-pathways activated by older growth hormone-releasing peptides such as GHRP-2 and GHRP-6.

Mechanism of action

GHS-R / ghrelin receptor agonism

Ipamorelin binds the GHS-R1a receptor on pituitary somatotrophs, mimicking ghrelin's endogenous signal and triggering pulsatile GH release.

Selectivity profile

The defining feature: at therapeutic doses, Ipamorelin does not significantly elevate cortisol, prolactin, or ACTH. Older GHRPs (GHRP-2, GHRP-6) hit those side-pathways, which is why Ipamorelin became dominant. Cortisol and prolactin elevation are the most clinically annoying side effects of the older class.

Synergy with GHRH analogs

Combining Ipamorelin with a GHRH analog (CJC-1295, sermorelin) produces a synergistic GH pulse, because the two peptides activate different receptors and signaling pathways. The combined effect is 2–3 times larger than either alone. Full combo explainer →

Half-life

Plasma half-life is approximately 2 hours. The GH-pulse window after dosing is on the order of 1 to 2 hours.

Commonly studied dosing protocols

These are not recommendations. Always consult a licensed healthcare provider before any clinical decision.

Subcutaneous (research-community range): 100 to 300 mcg per dose, once nightly before bed, on an empty stomach. Some research-community protocols dose 2–3 times per day.

Stacked with CJC-1295 (No DAC): the dominant approach. CJC-1295 100 mcg + Ipamorelin 100–300 mcg, once nightly. Full combo dosing →

Treatment duration: typical research-community cycles are 8 to 12 weeks. Long-term continuous use in healthy adults has not been formally characterized.

Side effects and safety profile

Reported in research and community settings:

  • Mild flushing or warmth shortly after injection (common, transient)
  • Injection-site redness or tenderness (common, mild)
  • Brief lightheadedness (uncommon)
  • Mild fluid retention (uncommon)
  • Headache (uncommon)

Notably absent: the appetite spikes and cortisol elevation seen with older GHRPs. This is the main reason Ipamorelin became dominant.

Theoretical concerns: GH/IGF-1 elevation interacts theoretically with cancer biology, avoid in active malignancy. Cautious use in diabetes (GH can raise blood glucose), sleep apnea, and carpal tunnel-prone individuals.

References

  1. Raun K, Hansen BS, Johansen NL, et al. (1998). "Ipamorelin, the first selective growth hormone secretagogue." Eur J Endocrinol, 139(5), 552–561. PubMed
  2. Johansen PB, Nowak J, Skjaerbaek C, et al. (1999). "Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats." Growth Horm IGF Res, 9(2), 106–113. PubMed
  3. Sigalos JT, Pastuszak AW. (2018). "The safety and efficacy of growth hormone secretagogues." Sex Med Rev, 6(1), 45–53. PubMed
  4. Andersen NB, Malmlöf K, Johansen PB, et al. (2001). "The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced osteopenia in adult male rats." Growth Horm IGF Res, 11(5), 266–272. PubMed
  5. Beck DE, Sweeney WB, McCarter MD; Ipamorelin Postoperative Ileus Study Group. (2014). "Prospective, randomized, controlled trial evaluating the efficacy of ipamorelin for the prevention of postoperative ileus." Curr Med Res Opin, 30(8), 1597–1605. PubMed
  6. U.S. Food and Drug Administration. (2023). "Pharmacy Compounding Guidance. FDA Category 2 List." FDA.gov
For educational and research purposes only. This is not medical advice. Ipamorelin is not FDA-approved and is on the FDA's Category 2 list as of September 2023. Consult a licensed healthcare provider before considering any peptide. PeptideLibraryHub is independent and does not sell peptides or accept money from anyone who does.