# Ipamorelin Research Doses — Preclinical and Clinical Context > Research-context only: doses studied in published ipamorelin preclinical and clinical literature, pharmacokinetics (half-life, clearance, volume of distribution), routes studied, and reagent-grade sourcing standards. ## Research Doses by Species and Study Context All dosing information is research-context only. Ipamorelin is not approved by the FDA, EMA, or any other regulatory agency for human use. **Rodent pharmacology (initial selectivity characterization).** Raun et al. (1998) established GH-releasing potency in anesthetized rats with an intravenous ED50 of 80 nmol/kg, and in conscious swine with an IV ED50 of 2.3 nmol/kg. [1] ACTH and cortisol responses were absent at all doses tested up to 200-fold the GH ED50. [1] **Rodent bone formation studies.** Johansen et al. (1999) administered 18, 90, or 450 mcg/day via subcutaneous injection divided into three daily doses for 15 days in adult female rats. [2] Andersen et al. (2001) used 100 mcg/kg three times daily subcutaneously for three months in 8-month-old female Wistar rats. [3] Svensson et al. (2000) administered 0.5 mg/kg/day by continuous subcutaneous infusion via osmotic minipump for 12 weeks in 13-week-old female Sprague-Dawley rats. [4] **Rodent nitrogen balance studies.** Aagaard et al. (2009) used 0.5 mg/kg/day subcutaneously in prednisolone-treated Sprague-Dawley rats. [7] **Rodent GI motility studies.** Venkova et al. (2009) administered a single IV dose of 1 mg/kg for acute transit studies and repetitive IV doses of 0.1 or 1 mg/kg four times daily for two days. [8] Greenwood-Van Meerveld et al. (2012) used IV doses of 0.014 and 0.14 mcmol/kg for gastric emptying studies. [9] **Human clinical trial.** Beck et al. (2014; NCT00672074) administered ipamorelin at 0.03 mg/kg intravenously twice daily for up to seven days post-bowel-resection surgery in 114 enrolled patients. [10] This is the only published dose from a controlled human clinical trial; the route was intravenous infusion. ## Pharmacokinetics Gobburu et al. (1999) conducted pharmacokinetic-pharmacodynamic modeling of ipamorelin in healthy human volunteers. [12] Key parameters: - Terminal half-life: approximately 2 hours - Clearance: 0.078 L/h/kg - Volume of distribution at steady-state: 0.22 L/kg - Time to peak GH (Tmax): approximately 40 minutes post-administration - PK linearity: linear (dose-proportional) across the dose range tested GH returned to negligible levels within 2–3 hours of dosing, consistent with the single discrete GH pulse per administration that characterizes ipamorelin's receptor pharmacology. [12] In male Sprague-Dawley rats, IV pharmacokinetics showed a plasma clearance approximately five-fold lower than GHRP-6. 60–80% of an administered dose was recovered from bile and urine as intact peptide. [11] Intranasal bioavailability in rats was approximately 20%. [11] ## Routes Studied in the Published Literature - **Intravenous bolus:** primary route in human clinical pharmacology (Gobburu 1999) and the Phase 2 trial (Beck 2014); also used in rat acute pharmacology (Raun 1998, Venkova 2009, Greenwood-Van Meerveld 2012) - **Subcutaneous injection:** primary route in most rodent chronic administration studies (Johansen 1999; Andersen 2001; Aagaard 2009) - **Subcutaneous continuous infusion (osmotic minipump):** used by Svensson et al. (2000) for the 12-week bone mineral content study - **Intranasal:** characterized pharmacokinetically in rats (Johansen et al. 1998); approximately 20% bioavailability - **Intraperitoneal:** used in ferret cisplatin model (2024) and mouse adiposity study (Lall 2001) No oral human bioavailability data have been published for ipamorelin. ## Reagent-Grade Sourcing: What Researchers Should Verify Research-grade ipamorelin is distributed as a lyophilized powder and is characterized by the following benchmarks: [16] - HPLC purity: ≥98% by reversed-phase HPLC (peak area method) - Identity confirmation: LC-MS molecular weight match to 711.86 Da (C38H49N9O5) - Amino acid analysis: confirming the pentapeptide sequence (Aib-His-D-2-Nal-D-Phe-Lys-NH2) - Storage: lyophilized powder at −20°C long-term; reconstituted at 4°C for short-term research use - COA documentation: lot number, purity percentage, MS identity confirmation, and storage specifications per lot Third-party COA documentation provides the most reliable evidence of reagent quality. Researchers should request the actual HPLC chromatogram and LC-MS spectrum rather than only the purity percentage summary. ## References [1] Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology. 1998;139(5):552-561. [2] Johansen PB et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Hormone & IGF Research. 1999;9(2):106-113. [3] Andersen NB et al. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation. Growth Hormone & IGF Research. 2001;11(5):266-272. [4] Svensson J et al. The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats. Journal of Endocrinology. 2000;165(3):569-577. [7] Aagaard NK et al. Growth hormone and growth hormone secretagogue effects on nitrogen balance and urea synthesis in steroid treated rats. Growth Hormone & IGF Research. 2009;19(5):426-431. [8] Venkova K et al. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. Journal of Pharmacology and Experimental Therapeutics. 2009;329(3):1110-1116. [9] Greenwood-Van Meerveld B et al. Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileus. Journal of Experimental Pharmacology. 2012;4:149-155. [10] Beck DE, Sweeney WB, McCarter MD. Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin. International Journal of Colorectal Disease. 2014;29(12):1527-1534. [11] Johansen PB et al. Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption. Xenobiotica. 1998;28(11):1083-1091. [12] Gobburu JV et al. Pharmacokinetic-Pharmacodynamic Modeling of Ipamorelin in Human Volunteers. Pharmaceutical Research. 1999;16(9):1412-1416. [13] Ankersen M et al. A new series of highly potent growth hormone-releasing peptides derived from ipamorelin. Journal of Medicinal Chemistry. 1998;41(19):3699-3706. [16] U.S. FDA. Bulk Drug Substance Nomination: Ipamorelin acetate / Ipamorelin free base (FDA-2024-N-4188). 2024. --- For research purposes only. Not for human consumption. This site does not sell any product and is not affiliated with any vendor.