Growth hormone-releasing activity of hexarelin in humans. A dose-response study

Eur J Clin Pharmacol. 1994;46(5):421-5. doi: 10.1007/BF00191904.


Hexarelin is a new hexapeptide (His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2) that stimulates the release of growth hormone both in vitro and in vivo. In this double-blind, placebo-controlled, rising-dose study we evaluated the growth hormone releasing activity of hexarelin in healthy human subjects. Twelve adult male volunteers received single intravenous boluses of 0.5, 1 and hexarelin as well as placebo. For safety, drug doses were given in a rising-dose fashion with placebo randomly inserted into the sequence. Plasma growth hormone concentrations increased dose-dependently after the injection of the peptide, peaking at about 30 min and then decreasing to baseline values within 240 min with a half-life of about 55 min. The mean peak plasma growth hormone concentrations (Cmax) were 3.9, 26.9, 52.3, 55.0 after 0, 0.5, 1 and 2, respectively. The corresponding areas under the curve of growth hormone plasma levels from drug injection to 180 min (AUC0-180) were 0.135, 1.412, 2.918 and 3.695 The theoretical maximum response (Emax) and the dose that produces half of the maximum response (ED50) were estimated using logistic regression. The calculated ED50 values were 0.50 and 0.64 for Cmax and AUC0-180, respectively. The corresponding Emaxs were 55.1 and 3936, thus indicating that the effect after the 2 dose is very close to the maximal response.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Blood Glucose / metabolism
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Electrocardiography / drug effects
  • Growth Hormone / blood*
  • Growth Substances / adverse effects
  • Growth Substances / pharmacokinetics
  • Growth Substances / pharmacology*
  • Half-Life
  • Hormones / blood
  • Humans
  • Male
  • Molecular Sequence Data
  • Oligopeptides / adverse effects
  • Oligopeptides / pharmacokinetics
  • Oligopeptides / pharmacology*


  • Blood Glucose
  • Growth Substances
  • Hormones
  • Oligopeptides
  • hexarelin
  • Growth Hormone