Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog

Summary

Human study in healthy men aged 20-40 (not older adults) that measured overnight GH pulsatility before and 1 week after a single injection of CJC-1295, a long-acting GHRH analog that binds to albumin after injection (half-life about 8 days). The question was whether continuous stimulation from this analog would flatten the normal pulsatile pattern of GH release, and which features of GH secretion tracked the rise in IGF-I. The study did not measure body composition and did not include older adults.

Key Findings

• GH secretion increased after CJC-1295 while pulsatility was preserved: the frequency and magnitude of GH secretory pulses were unaltered
• Basal (trough) GH levels rose 7.5-fold (P < 0.0001), which drove a 46% increase in mean GH (P < 0.01)
• IGF-I rose 45% (P < 0.001)
• No significant differences between the 60 and 90 µg/kg doses
• The IGF-I increase did not correlate with any measured parameter of GH secretion; the authors point to the rise in trough GH as important for the IGF-I effect
• The authors conclude that long-acting GHRH preparations may have clinical utility in patients whose pituitary can still secrete GH

Methodology

Healthy men aged 20-40 years received a single injection of either 60 or 90 µg/kg CJC-1295. GH was sampled every 20 minutes over an overnight 12-hour period before and 1 week after the injection, and GH secretion parameters were compared with the change in IGF-I. The abstract does not report the number of participants.

Limitations

• Healthy young men only; results may not apply to older adults, women, or people with GH deficiency
• Single dose with a 1-week follow-up; no repeated-dosing data
• Number of participants not reported in the abstract
• Hormone levels only; no body composition, metabolic, or functional outcomes
• Only the long-acting, albumin-binding CJC-1295 was tested; results should not be assumed to carry over to short-acting “no-DAC” products

Relevance to Content

This is the main human evidence that CJC-1295 keeps GH release pulsatile while raising overall GH and IGF-I. It does not address aging or body composition directly. The study enrolled men aged 20-40 and measured only hormone levels, so claims about CJC-1295 for aging or body composition need other evidence.

See Also

• Parent compound: CJC-1295
• cjc-1295-dac-gh-release-pharmacokinetics: earlier CJC-1295 dose-ranging trials in healthy adults