What is the recommended dosing for Ipamorelin (growth hormone secretagogue)?

Ipamorelin Dosing Recommendations

The recommended dosing for Ipamorelin is 1 mg/kg administered intravenously or subcutaneously, which has been shown to effectively stimulate growth hormone release with minimal side effects. 1

Pharmacology and Mechanism of Action

• Ipamorelin is a synthetic pentapeptide that functions as a growth hormone secretagogue (GHS), specifically stimulating growth hormone (GH) release from the anterior pituitary 2
• It acts as a selective agonist of the ghrelin receptor, demonstrating distinct and specific GH-releasing properties 2
• Pharmacokinetic studies show Ipamorelin has a short terminal half-life of approximately 2 hours, with a clearance of 0.078 L/h/kg and a volume of distribution at steady-state of 0.22 L/kg 1

Dosing Guidelines

Standard Dosing

• For intravenous administration: 1 mg/kg as a bolus infusion has been shown to effectively decrease time to first bowel movement in postoperative ileus models 3
• For subcutaneous administration: 0.1-1 mg/kg has demonstrated efficacy in stimulating GH release 4

Multiple Dosing Regimens

• For conditions requiring sustained effects (such as postoperative ileus), a repetitive dosing regimen of 0.1-1 mg/kg administered four times daily at 3-hour intervals has shown superior efficacy compared to single dosing 3
• This multiple dosing approach significantly increases cumulative outcomes including food intake and weight gain compared to single dosing 3

Dose-Response Relationship

• Ipamorelin demonstrates dose-dependent effects on growth hormone release 2
• The concentration required for half-maximal GH stimulation (SC50) is approximately 214 nmol/L 1
• Maximal GH production rate with Ipamorelin stimulation is around 694 mIU/L/h 1
• The pharmacokinetic parameters show dose-proportionality across different infusion rates (4.21-140.45 nmol/kg) 1

Clinical Considerations

• GH response to Ipamorelin typically shows a single episode of GH release with a peak at approximately 0.67 hours after administration 1
• Inter-individual variability in pharmacodynamic response is greater than pharmacokinetic variability, suggesting the need for clinical monitoring of effect 1
• Unlike some other growth hormone secretagogues, Ipamorelin does not significantly affect total IGF-I levels, IGFBPs, or serum markers of bone formation and resorption at standard doses 2

Special Populations

• In pediatric populations with growth disorders, growth hormone secretagogues are typically administered at bedtime to mimic the natural circadian rhythm of GH secretion 5
• While specific pediatric dosing for Ipamorelin is not established, similar GH secretagogues like sermorelin are administered at 30 μg/kg bodyweight subcutaneously at bedtime for children with idiopathic growth hormone deficiency 5

Monitoring and Safety

• Monitor for common side effects which may include transient facial flushing and pain at injection site 5
• The pituitary GH content remains unchanged with Ipamorelin treatment, suggesting minimal risk of GH depletion with proper dosing 2
• When evaluating treatment response, allow sufficient time (3-6 months) to properly assess clinical effects 6

Potential Applications

• Ipamorelin may be beneficial in conditions requiring enhanced gastric motility, such as postoperative ileus 3
• It has shown promise in promoting longitudinal bone growth in preclinical models 2
• The clinical utility for treating children with growth retardation requires further investigation in clinical studies 2