Ipamorelin Deep-Dive
Also known as: NNC 26-0161 · Ghrelin Receptor Agonist (selective)
Ipamorelin is a synthetic pentapeptide selective ghrelin receptor (GHSR-1a) agonist. Researchers investigate its capacity to stimulate pulsatile growth-hormone release from the anterior pituitary without significant elevations in cortisol, prolactin, or aldosterone — a selectivity profile that distinguishes it from earlier secretagogues like GHRP-2 and GHRP-6.
Plasma Half-Life
~2 hours
Logarithmic scale · 2 hr mapped
Tissue Residency
Functional GH pulse window 2–4 hours post-administration
Quick Facts
- Typical dose
- 200–300 mcg, 1–3x daily
- Range
- 100 mcg – 500 mcg per dose
- Route
- Subcutaneous injection. Common timing: pre-bed for sleep-window pulse, optionally pre-workout and morning.
- Cycle pattern
- Common practitioner pattern: 8–12 weeks on, 4 weeks off to limit pituitary downregulation research concerns. Some protocols use 5-on-2-off weekly cycling.
- Primary evidence tier
- Expert
Mechanism of Action
Ipamorelin is a synthetic pentapeptide selective ghrelin receptor (GHSR-1a) agonist. Researchers investigate its capacity to stimulate pulsatile growth-hormone release from the anterior pituitary without significant elevations in cortisol, prolactin, or aldosterone — a selectivity profile that distinguishes it from earlier secretagogues like GHRP-2 and GHRP-6.
Researchers investigate Ipamorelin in the broader context of the GH Axiscompound class. The compound's proposed relationship to underlying physiology is typically framed against the ATP Shortage axis — a framework DoseCraft uses to organize research priorities across the 90+ compound library.
In the practitioner corpus that trains the DoseCraft AI copilot, Ipamorelin's mechanism is repeatedly cross-referenced against its pharmacokinetic profile (plasma half-life ~2 hours) because dosing cadence, stack selection, and cycling structure all derive from the PK window. This is the core difference between a static calculator and a PK-aware reasoning layer.
Pharmacokinetics
Plasma Half-Life (Logarithmic)
~2 hours
Logarithmic scale · 2 hr mapped
Tissue Residency
Functional GH pulse window 2–4 hours post-administration
Ipamorelin has a plasma half-life of approximately ~2 hours. This window is the primary driver of every downstream protocol decision: dosing frequency, stack overlap, cycling length, and the observable duration of subjective response.
Beyond the plasma window, functional gh pulse window 2–4 hours post-administration. This tissue-residency or functional-duration behavior is why practitioner protocols often deviate from what raw plasma half-life alone would suggest.
In the DoseCraft PK model, this compound is mapped onto the same decay-curve framework that powers the half-life visualizer in the app — every stack built in the Protocol Builder factors in the half-life overlap of Ipamorelinalongside any co-administered compounds. Static calculators elsewhere ignore this; it's why the practitioner corpus consistently flags half-life literacy as a top-three safety variable.
From real clinicians · not PubMed abstracts
Practitioner Protocols
Practitioner Corpus
Sourced from 10,000+ hours of clinician-validated protocols, bloodwork reviews, and cycle audits. Not PubMed. Not Reddit.
Clinicians who run high-volume peptide practices report Ipamorelin as the cleanest selective ghrelin agonist in active practitioner use, citing its lack of significant cortisol or prolactin elevation as the primary differentiator from older secretagogues. In protocol audits we've reviewed, the Ipamorelin + CJC-1295 (no DAC) combination — administered pre-bed to align with the natural sleep-cycle GH pulse — appears in nearly every GH-axis research protocol. The 2-hour half-life supports multiple daily pulses for protocols pursuing higher GH exposure research.
Dosing
200–300 mcg, 1–3x daily
Subcutaneous injection. Common timing: pre-bed for sleep-window pulse, optionally pre-workout and morning.
Cycle
Common practitioner pattern: 8–12 weeks on, 4 weeks off to limit pituitary downregulation research concerns. Some protocols use 5-on-2-off weekly cycling.
Evidence Breakdown
Every finding about Ipamorelinis categorized across three independent evidence lanes. You always know what research tier you’re acting on.
- Phase II human trials investigated Ipamorelin for postoperative ileus; trials confirmed the favorable selectivity profile (no significant cortisol or prolactin elevation) but did not advance to approval.
- Strong practitioner consensus as the canonical selective GH secretagogue. CJC-1295 + Ipamorelin pre-bed protocol is near-universal in audited GH-axis research.
- Community protocol logs investigate broader applications including recovery and body-composition research; emerging work explores split-dose protocols for sustained pulsatile exposure.
Cycling & Stack Considerations
Cycling Protocol
Common practitioner pattern: 8–12 weeks on, 4 weeks off to limit pituitary downregulation research concerns. Some protocols use 5-on-2-off weekly cycling.
Common Stacks
- •Ipamorelin + CJC-1295 (no DAC) — the canonical GH pulse stack
- •Ipamorelin + CJC-1295 with DAC — for less frequent dosing protocols
- •Ipamorelin + BPC-157 (recovery + GH pulse research)
Interactions & Overlap
- •CJC-1295 (canonical GH-axis pairing — the dominant practitioner stack)
- •Sermorelin (alternative GHRH; mechanistically overlapping)
- •Tesamorelin (GHRH analog; not typically co-administered)
Honest negatives · the part other trackers skip
Contraindications & Watch-Outs
Research Watch-Outs
- Active malignancy — GH-axis stimulation theoretically contraindicated
- Pregnancy and lactation — no human safety data
- Active diabetic ketoacidosis or uncontrolled hyperglycemia
- Pituitary disorders — practitioner consultation required
Ipamorelin FAQs
What is the half-life of Ipamorelin?
Ipamorelin has an approximate 2-hour plasma half-life, with the functional GH pulse window extending 2–4 hours post-administration. This short half-life is why practitioner protocols typically use 1–3 daily doses.
What is the typical Ipamorelin dose?
The most common practitioner protocol uses 200–300 mcg per dose, 1–3 times daily. Pre-bed dosing is near-universal to align with the natural sleep-cycle GH pulse; additional pre-workout and morning doses appear in higher-volume protocols.
Is Ipamorelin better than CJC-1295?
They operate on different receptors and are typically stacked, not compared. Ipamorelin is a ghrelin-receptor agonist; CJC-1295 is a GHRH analog. The combination is the canonical GH-axis research stack.
Does Ipamorelin cause cortisol or prolactin elevation?
The selectivity profile in published research and practitioner observation is that Ipamorelin does not produce significant cortisol or prolactin elevation at standard research doses — the primary differentiator from older secretagogues like GHRP-2 and GHRP-6.
How long should an Ipamorelin cycle run?
Common practitioner cycles run 8–12 weeks on, with 4 weeks off to limit pituitary-downregulation research concerns. Some protocols use 5-on-2-off weekly cycling for continuous research applications.
Can Ipamorelin be taken pre-workout?
Yes — pre-workout dosing is one of the three common timing windows (alongside pre-bed and morning). Practitioner protocols pursuing higher GH exposure typically use all three windows.
Is Ipamorelin FDA approved?
Ipamorelin is not FDA approved for any indication and is sold for research use only. Phase II trials investigated postoperative ileus applications but did not advance to approval.
Related Compounds
Track your Ipamorelin protocol in DoseCraft
The PK-aware protocol builder models ~2 hours decay, checks stack overlap, and flags contraindications — built on the same practitioner corpus that powers this page.
See pricingFor research use only. Not for human consumption. Not evaluated by the FDA. Not intended to diagnose, treat, cure, or prevent any disease. Content on this page is educational and does not constitute medical advice, dosing guidance, or a protocol recommendation. Consult a qualified clinician before undertaking any research involving peptide compounds.