Ipamorelin — Reconstitution & Dosage Calculator

What Is Ipamorelin?

Ipamorelin is a synthetic pentapeptide — a five–amino-acid chain (Aib-His-D-2-Nal-D-Phe-Lys-NH₂) — belonging to the growth-hormone-releasing peptide (GHRP) class. It acts as an agonist at the ghrelin receptor (GHS-R1a), the same receptor targeted by the endogenous hormone ghrelin, and stimulates the pituitary to release growth hormone (GH). First described in 1998 by Raun et al. at Novo Nordisk (development code NNC 26-0161), it was characterized as one of the first GH secretagogues to release GH with a notably clean selectivity profile in preclinical models.

What distinguished ipamorelin from earlier secretagogues like GHRP-6 was its reported selectivity: in the original animal work it stimulated GH release without the concurrent rises in ACTH and cortisol seen with less selective compounds. Because it works through the ghrelin-receptor pathway rather than the GHRH pathway, ipamorelin is mechanistically complementary to GHRH analogs such as CJC-1295 and Sermorelin, and the two classes are frequently studied together in the secretagogue literature. Note that the free-base molecular weight (711.85 g/mol) differs from the commonly supplied ipamorelin acetate salt, which carries additional mass from the counter-ion.

Research Context

Evidence Level: The following summarizes findings from peer-reviewed preclinical studies (animal models and in vitro experiments) plus a small number of early-phase human studies. Ipamorelin is not an approved drug. Findings should not be interpreted as clinical recommendations.

Overview

The ipamorelin literature is modest in size (roughly 50 PubMed-indexed studies) and clusters around four themes: the mechanism and selectivity of ghrelin-receptor-mediated GH release, human pharmacokinetics, effects on gastrointestinal motility, and effects on bone and body composition. Most primary efficacy data derive from rodent models; the human evidence base consists of a first-in-human pharmacokinetic study and a Phase 2 program in postoperative ileus. Evidence maturity is highest for the pharmacokinetic and GI-motility questions and remains preliminary for bone and body-composition endpoints.

Mechanism and Receptor Selectivity

The defining feature of ipamorelin is receptor selectivity. In the foundational study, Raun et al. (1998) reported that ipamorelin released GH in a dose-dependent manner comparable to GHRP-6, but — unlike GHRP-6 — did not elevate ACTH or cortisol at GH-releasing doses in their models. This selectivity is attributed to its action as a relatively pure GHS-R1a agonist, avoiding the off-target activity that produces cortisol and prolactin release with older peptides. The mechanism is distinct from that of GHRH analogs: ghrelin-receptor agonists and GHRH act on separate receptors and separate intracellular pathways, which is the pharmacological basis for the frequently studied secretagogue combinations.

Human Pharmacokinetics

The clearest human data come from an early dose-escalation study. Gobburu et al. (1999) administered ipamorelin to healthy male volunteers and reported dose-proportional pharmacokinetics with a terminal half-life of approximately two hours and measurable changes in circulating GH. The short half-life is mechanistically consistent with the peptide’s small size and lack of any albumin-binding modification — a contrast with long-acting analogs like CJC-1295 with DAC, and the reason research dosing schedules for ipamorelin typically use multiple daily administrations rather than once-weekly.

Gastrointestinal Motility

Because the ghrelin receptor is expressed in the enteric nervous system, ipamorelin has been investigated as a prokinetic agent. In rodent models of postoperative ileus, Venkova et al. (2009) and later Greenwood-Van Meerveld et al. (2016) reported that the ghrelin mimetic accelerated gastric emptying and restored disturbed gut motility. This preclinical work supported a human proof-of-concept trial: Beck et al. (2015) conducted a prospective, randomized, controlled study evaluating ipamorelin for acceleration of GI recovery — one of the few controlled human datasets for the peptide. More recent work by Lu et al. (2024) examined ghrelin-receptor agonists, including ipamorelin, on ileal contractility and cisplatin-induced weight loss in ferrets.

Bone and Body Composition

Ipamorelin’s downstream GH/IGF-1 effects have been studied in the context of skeletal growth. Johansen et al. (1999) administered subcutaneous ipamorelin across a dose range in adult female rats and measured longitudinal bone growth rate, body-weight gain, and GH release. Svensson et al. (2000) compared ipamorelin and GHRP-6 for effects on bone mineral content in the same animal model. These findings are preclinical and have not been reproduced in controlled human trials; contemporary reviews of the secretagogue class, such as Sinha et al. (2020), discuss growth-hormone secretagogues as a possible adjunct for body-composition management while emphasizing the absence of definitive outcome data.

Methodological Observations

The ipamorelin literature is dominated by small-sample rodent studies using subcutaneous administration, with GH and IGF-1 concentrations as the primary endpoints. The two human datasets (Gobburu 1999; Beck 2015) are limited in size and were designed to assess pharmacokinetics and GI recovery rather than long-term metabolic outcomes. Much of the original characterization work originated from a single pharmaceutical development program, and independent replication of the selectivity findings across laboratories remains limited.

Research Gaps and Limitations

• Evidence level gap — No large-scale randomized controlled trials support the body-composition or anti-aging claims commonly made in consumer channels. The Beck (2015) trial addressed GI recovery, not physique or performance endpoints.
• Methodological gap — Rodent sample sizes are small, follow-up is short, and dose-response relationships for chronic administration are not well characterized.
• Translational gap — Animal doses (often expressed per kilogram) have not been validated against human-equivalent doses through formal pharmacokinetic bridging.
• Safety gap — Long-term safety data beyond short study windows are absent; chronic GH-axis stimulation raises theoretical concerns (insulin sensitivity, fluid retention) that lack controlled human follow-up.
• Regulatory context — Reviews such as Coutinho et al. (2026) and Mendias et al. (2026) classify ipamorelin among unapproved “gray-market” enhancement peptides, noting the absence of regulatory oversight for products sold outside clinical channels.

Reconstitution Mathematics

Accurate reconstitution is critical for consistent dosing in any laboratory protocol. The interactive calculator on this page handles all the arithmetic — but understanding the underlying formula is useful for verification:

Concentration (mg/mL) = Vial Size (mg) ÷ BAC Water Added (mL)
Dose Volume (mL)      = Desired Dose (mg) ÷ Concentration (mg/mL)
Syringe Units (IU)    = Dose Volume (mL) × 100   [for U-100 insulin syringe]

Common laboratory reconstitution examples:

Use the interactive calculator on this page for any custom vial size, water volume, or dose.

Common Research Dosing Parameters

Based on published preclinical literature and early-phase human studies. These are not clinical recommendations.

Unlike weight-based rodent protocols, secretagogue research doses are most often expressed as fixed microgram amounts. The following table summarizes parameters reported or commonly modeled across ipamorelin studies:

Key observations from the literature:

• Subcutaneous administration is standard; the ~2-hour half-life (Gobburu et al., 1999) is why multiple daily doses are modeled rather than a single dose
• GH release is pulsatile — timing relative to meals and other secretagogues is a common experimental variable
• Selectivity for GH over ACTH/cortisol was a defining finding but was established in animal models, not chronic human dosing

Graduated Dosing Design from Published Studies

The following graduated design reflects dosing escalation patterns discussed in the secretagogue literature. It is not a clinical protocol.

Reconstitution assumption: 5 mg vial + 2 mL BAC water = 2.5 mg/mL concentration

*Example doses calculated for illustrative purposes based on common vial configurations.

Dose range sources:

• 100–300 µg fixed dosing reflects the microgram ranges modeled in secretagogue research summarized by Sinha et al. (2020)
• Pharmacokinetic basis for multiple daily dosing from Gobburu et al. (1999)
• GI-motility dosing context from the human proof-of-concept trial by Beck et al. (2015)

Important notes:

• Fixed microgram dosing is used because human ipamorelin studies did not establish weight-based regimens
• IU values assume a U-100 insulin syringe (1 IU = 0.01 mL)
• No approved human dosing exists; the above reflects research parameters, not therapeutic guidance

Stability & Storage

Bacteriostatic water (BAC water, 0.9% benzyl alcohol) is the standard diluent for reconstitution because benzyl alcohol acts as a preservative, extending the usable life of the reconstituted solution.

Reconstitution procedure (standard laboratory protocol):

1. Allow vial to reach room temperature (~15 minutes)
2. Wipe septum with 70% isopropyl alcohol
3. Draw desired BAC water volume into a sterile syringe
4. Insert needle at a 45° angle and inject slowly along the vial wall — do not inject directly onto the lyophilized cake
5. Gently swirl (do not shake or vortex) until fully dissolved
6. Label vial with date, concentration, and store per table above

Frequently Asked Questions

How many units do I draw for 200 mcg of Ipamorelin?

It depends on your reconstitution ratio. With a 5 mg vial in 2 mL BAC water (2.5 mg/mL concentration), a 200 mcg dose = 8 units on a U-100 insulin syringe. With 5 mL BAC water instead, the same dose = 20 units. Use the calculator above for your specific setup.

What is the difference between Ipamorelin and CJC-1295?

They act on different receptors. Ipamorelin is a ghrelin-receptor (GHS-R1a) agonist, while CJC-1295 is a GHRH analog. Because the pathways are complementary, the two are frequently studied together in the secretagogue literature. Use the multi-peptide mode to compute combined injection volumes when modeling both in one protocol.

Why is Ipamorelin dosed multiple times per day?

Its terminal half-life is only about two hours (Gobburu et al., 1999) because it has no albumin-binding modification. Research schedules therefore model 1–3 daily administrations, unlike long-acting analogs such as CJC-1295 with DAC, which persist for days.

Is Ipamorelin the same as GHRP-6 or GHRP-2?

All three are ghrelin-receptor agonists, but ipamorelin was characterized as more selective — in animal models it released GH without the ACTH/cortisol elevation and appetite stimulation associated with GHRP-6. The three are sometimes compared head-to-head in the same studies.

How long does reconstituted Ipamorelin last in the refrigerator?

Reconstituted in bacteriostatic water and stored at 2–8 °C, ipamorelin remains stable for up to 28 days. Always use a fresh alcohol swab on the vial septum before each draw. If the solution becomes cloudy or discolored, discard it.

Does Ipamorelin acetate change the reconstitution math?

No. The salt form affects the powder’s mass slightly but not the reconstitution arithmetic — you still divide the labeled peptide content (mg) by the BAC water volume (mL) to get concentration. Use the labeled vial size in the calculator above.

FOR RESEARCH PURPOSES ONLY. Not for human consumption. Not for veterinary use. Not a drug, food, or cosmetic.