Growth Hormone Axis · Selective GHS · Compounded 503A
Ipamorelin: the clean GH pulse.
Ipamorelin is a pentapeptide that selectively activates the ghrelin / GHS-R1a receptor on the pituitary. The result is a sharp, clean pulse of growth hormone — without the cortisol, prolactin, or ACTH rise that older secretagogues produced. It is the cleanest GH secretagogue in clinical use.
What Ipamorelin is
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) originally developed at Novo Nordisk in the late 1990s as a selective growth hormone secretagogue. It binds the ghrelin receptor (GHS-R1a) on the pituitary but, unlike earlier compounds in its class, does not appreciably affect cortisol, prolactin, ACTH, FSH, LH, or TSH.
That selectivity is the entire reason ipamorelin is widely used. Older GH secretagogues like GHRP-2 and GHRP-6 also work but pull cortisol up — which limits how often they can be dosed without unwanted effects.
Ipamorelin is almost always prescribed alongside a GHRH analog (sermorelin, CJC-1295, or tesamorelin). The two work through different receptors and produce a much larger combined GH pulse than either alone — this is the basis of the popular CJC-1295 + ipamorelin protocol.
How it works
Ipamorelin binds GHS-R1a, the ghrelin receptor expressed on pituitary somatotrophs. This depolarizes the cell and triggers release of stored growth hormone. A GHRH analog given at the same time activates a separate (GHRH) receptor that simultaneously stimulates both GH release and GH synthesis. The two signals synergize.
Because ipamorelin works through the ghrelin pathway, it preserves the pulsatile pattern of natural GH release rather than producing the sustained elevation seen with exogenous HGH. The pituitary remains in control. The hypothalamic feedback loop remains intact.
The downstream effect is the same as any GH-axis support: a modest, physiologic rise in IGF-1, with downstream effects on body composition, sleep architecture, recovery, and tissue repair.
What patients use it for
Pulsatile GH release
Ipamorelin produces a sharp, short GH pulse that mimics the body's natural pattern. This is generally better tolerated and more sustainable than continuous GH replacement.
Clean side-effect profile
No meaningful cortisol, prolactin, or ACTH rise. This is the key clinical advantage and the reason ipamorelin is preferred over older secretagogues for chronic protocols.
Deeper sleep architecture
Most natural GH release happens during slow-wave sleep. Ipamorelin (typically dosed at bedtime alongside a GHRH analog) reinforces this and often improves perceived sleep quality within 2–4 weeks.
Body composition support
Through downstream IGF-1, ipamorelin contributes to lean mass preservation and modest improvements in fat oxidation — particularly when combined with resistance training.
Recovery and tissue repair
GH supports collagen synthesis and tissue repair. Patients commonly report improved recovery from exercise and faster healing of minor injuries.
Evidence summary
Raun K et al. (Novo Nordisk, 1998) characterized ipamorelin's selectivity and showed potent GH release in pigs and humans without cortisol or prolactin elevation — the founding pharmacology paper.
Sinha DK et al. (2020) review of growth hormone secretagogues in adult clinical practice characterizes ipamorelin as the best-tolerated agent in its class and the one most commonly used in combination protocols.
Direct large-scale RCT evidence in healthy adults is limited — ipamorelin's clinical use is largely extrapolated from its pharmacology, from GHRP-class trial data, and from physician outcome experience. Honest framing matters.
Dosing and clinical context
General clinical context only. Kindr Health physicians determine the appropriate dose and protocol for each patient based on history and labs. This is not a prescription or dosing recommendation.
Ipamorelin is typically dosed 100–300 mcg subcutaneously, once at bedtime. Many protocols add a morning dose pre- or post-training for additional GH pulses.
Almost always paired with a GHRH analog — usually CJC-1295 (no DAC) or sermorelin — because the combination produces a substantially larger and longer GH pulse than ipamorelin alone.
Cycled protocols (e.g. 5 days on, 2 days off; or 8 weeks on, 4 weeks off) are common to preserve pituitary responsiveness, though the necessity of cycling is debated in the literature.
Safety and contraindications
Generally very well tolerated. Mild injection-site reactions and occasional transient head pressure with the initial pulse are the most common reports.
Contraindications: pregnancy, active malignancy, pituitary disease, severe untreated diabetes. Caution in patients with active retinopathy.
Baseline IGF-1 required. Recheck at 8–12 weeks. Dose adjusted to keep IGF-1 in the upper-normal age-adjusted range — never supraphysiologic.
Who it's typically considered for
- Adults seeking a GH-axis support that does not raise cortisol or prolactin
- Patients in midlife with sleep, recovery, or lean-mass concerns
- Patients already on or considering CJC-1295 (ipamorelin is the standard pairing)
- Women in perimenopause/menopause wanting a gentler entry to GH-axis support
Frequently asked questions
Why is ipamorelin almost always combined with CJC-1295?
CJC-1295 (a GHRH analog) and ipamorelin (a ghrelin-receptor agonist) act through two different receptors. Together they produce a much larger and longer GH pulse than either alone — and the combined pulse is closer to a natural physiologic release.
Is ipamorelin FDA-approved?
No. Ipamorelin is not FDA-approved for any indication. Compounded ipamorelin is prepared by licensed 503A pharmacies under physician prescription for off-label use.
How long until I feel something?
Sleep is usually the first thing to shift — most patients notice deeper, more restorative sleep within 2–4 weeks. Recovery and energy follow at 4–8 weeks. Body composition changes appear at 3–6 months of consistent therapy.
Does ipamorelin cause weight gain or fluid retention?
At physiologic doses, ipamorelin does not typically cause meaningful fluid retention. This is one of its advantages over exogenous HGH, which more commonly produces edema at therapeutic doses.
Will it spike my prolactin or cortisol?
No — that is exactly what makes ipamorelin different from older secretagogues like GHRP-2 and GHRP-6. Selectivity for GH release without cortisol or prolactin elevation is its defining feature.
Can women in menopause use ipamorelin?
Yes. Many women in perimenopause and menopause use ipamorelin (typically with CJC-1295) for sleep, recovery, and body composition. It is commonly layered with HRT, not in place of it.
Do I need to cycle ipamorelin?
Many physicians cycle (e.g. 5 days on / 2 off, or 8 weeks on / 4 weeks off) to preserve pituitary responsiveness. The evidence for mandatory cycling is mixed; your kindr physician will design the schedule based on labs and response.
Sources
- Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology (1998). — academic.oup.com/ejendo/article-pdf/139/5/552/29977180/1390552.pdf
- Sinha DK et al. Beyond the androgen receptor: the role of growth hormone secretagogues. Translational Andrology and Urology (2020). — www.ncbi.nlm.nih.gov/pmc/articles/PMC7108996
- Beck DE et al. Ipamorelin in the management of postoperative ileus. Annals of Surgery (2014) — clinical safety data. — pubmed.ncbi.nlm.nih.gov/24509192
- Khorram O et al. Effects of [norleucine27]growth hormone-releasing hormone (1-29) NH2 administration on the immune system of aging men and women. JCEM (1997) — GHRH analog reference. — pubmed.ncbi.nlm.nih.gov/9192030
Considering Ipamorelin?
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Medically reviewed by Dr. Ana Lisa Carr, MD, MBA
Board-Certified Family Medicine Physician · Lead Provider / Medical Reviewer
NPI 1689841744 · Last reviewed: May 10, 2026
Last reviewed May 10, 2026. Compounded medications are prepared by FDA-registered 503A pharmacies and are not FDA-approved drug products. Prescriptions require a clinical evaluation; a Kindr Health physician determines eligibility. Not for use in pregnancy. This page provides educational information and is not medical advice.