GH responsiveness to repeated GHRH or hexarelin administration in normal adults

What Was Tested

The paper reports a study of Exogenous HGH, sermorelin & older GHRPs (why they're passed over) and GHRH (Growth Hormone-Releasing Hormone), published as a randomized controlled trial.

The first GHRH injection caused a clear rise in serum GH levels in all subjects (mean GH nAUC/h, test a: 832.1 +/- 59.4 ng/ml/h, range: 723.7-1074.0 ng/ml/h; test b: 859.2 +/- 122.9 ng/ml/h, range 618.0-1422.7 ng/ml/h).

After the first GHRH bolus, the second GHRH injection (test a) was unable to sustain GH elevated levels (mean GH nAUC: 74.5 +/- 26.5 ng/ml/h, range: 9.7-182.2 ng/ml/h), while hexarelin administration (test b) caused a clear GH rise in all subjects (GH nAUC: 1049.7 +/- 105.2 ng/ml/h, range: 786.0-1356.0 ng/ml/h).

Who Took Part

According to the abstract, 6 adults were involved.

By PubMed's age tags, the people studied were adults, both men and women.

How the Study Was Run

The researchers set it up as a randomized study.

Because people in this Exogenous HGH, sermorelin & older GHRPs (why they're passed over) study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

What Was Measured

The first GHRH injection caused a clear rise in serum GH levels in all subjects (mean GH nAUC/h, test a: 832.1 +/- 59.4 ng/ml/h, range: 723.7-1074.0 ng/ml/h; test b: 859.2 +/- 122.9 ng/ml/h, range 618.0-1422.7 ng/ml/h).

After the first GHRH bolus, the second GHRH injection (test a) was unable to sustain GH elevated levels (mean GH nAUC: 74.5 +/- 26.5 ng/ml/h, range: 9.7-182.2 ng/ml/h), while hexarelin administration (test b) caused a clear GH rise in all subjects (GH nAUC: 1049.7 +/- 105.2 ng/ml/h, range: 786.0-1356.0 ng/ml/h).

PubMed files the paper under topics including Growth Hormone, Growth Hormone-Releasing Hormone, Growth Substances and Oligopeptides.

What This Means in Plain Language

The paper is a randomized study of Exogenous HGH, sermorelin & older GHRPs (why they're passed over) and GHRH (Growth Hormone-Releasing Hormone) in 6 adults.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The publication is from 1995 (Journal of endocrinological investigation), a journal based in Italy.

More context: the Exogenous HGH, sermorelin & older GHRPs (why they're passed over) compound page and the GHRH (Growth Hormone-Releasing Hormone) compound page, all human trials.