The effect of intravenous, subcutaneous, and intranasal GH-RH analog, [Nle27]GHRH(1-29)-NH2, on growth hormone secretion in normal men: dose-response relationships.
Vance. M L ML; Evans. W S WS; Kaiser. D L DL; Burke. R L RL; Rivier. J J; Vale. W W; Thorner. M O MO
Key Findings
- IV, subcutaneous, and intranasal routes all stimulate GH release
- Subcutaneous dosing requires ~10Ă— the IV dose for similar GH levels; intranasal requires ~30Ă— and yields only ~20% of the IV effect
- GH peaks at ~30 min after dosing and returns to baseline by ~2 h, with onset in 5‑10 min
Practical Outcomes
- For DIY users, subcutaneous injection is the most practical and effective way to use sermorelin; plan to use a higher dose than the IV reference (roughly tenfold) to achieve desired GH spikes. Intranasal delivery is inefficient and not recommended for meaningful GH elevation. Expect a rapid rise in GH within 10 min, peak at half an hour, and a short‑lasting effect lasting about two hours.
Summary
The study shows that the GH‑releasing peptide [Nle27]GHRH(1‑29)NH2 (similar to sermorelin) can boost growth hormone when given IV, under the skin, or as a nasal spray. Injecting under the skin works well but needs about ten times the dose used for IV, while the nasal spray needs about thirty times the IV dose and only gives about one‑fifth the hormone boost. The hormone rise starts within 5‑10 minutes, peaks around 30 minutes, and returns to normal after about two hours, with no side effects reported.
Abstract
A 29 amino acid analog of growth hormone releasing hormone (GH-RH)-40 was given intravenously, subcutaneously, and intranasally to normal men to determine its effectiveness in stimulating growth hormone (GH) release. The GH-RH analog, [Nle27]GH-RH(1-29)-NH2, is an amidated 29 amino acid peptide that has one amino acid substitution at position 27. This peptide stimulates GH secretion when given by the intravenous, subcutaneous, and intranasal routes without adverse effect. The degree of GH stimulation was variable among subjects and the greatest amount of stimulation occurred with the highest doses. GH stimulation occurred in a dose-responsive manner after all three routes of administration. A tenfold higher subcutaneous dose was required to stimulate a comparable amount of GH secretion as compared with intravenous administration, and a thirtyfold higher intranasal than intravenous dose was required to stimulate approximately one fifth the amount of GH release. For comparison, one dose of GH-RH-40, 1 microgram/kg, was administered intravenously. GH secretion after 1 microgram/kg GH-RH-40 and 1 microgram/kg Nle27 GH-RH was comparable between the two groups of subjects. Stimulation of GH secretion by Nle27 GH-RH occurred within 5 minutes of intravenous and within 10 minutes of subcutaneous and intranasal administration; peak GH levels were observed within 30 minutes. GH levels declined and returned to near baseline levels 2 hours after administration of the analog.(ABSTRACT TRUNCATED AT 250 WORDS)
Study Information
pubmed
1986
1986-12-01T00:00:00.000Z
10.1038/clpt.1986.237
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