Growth Hormone and the Case for Sermorelin

A comprehensive review published on the National Institutes of Health's National Library of Medicine platform examined the relationship between age-related growth hormone decline and its measurable effects on body composition, metabolism, and physical function in men.

Researchers found that after the third decade of life, growth hormone secretion declines approximately 15% per decade. By age 55, daily GH output drops to roughly one-sixth of peak levels seen at puberty. This decline is directly associated with loss of lean body mass, increased visceral fat, reduced bone density, decreased sleep quality, and impaired cognitive function — changes that closely parallel those observed in clinical growth hormone deficiency.

Key Findings on Sermorelin (GHRH 1-29):

In a 6-month clinical trial of daily bedtime sermorelin injections in older adults, researchers found:

• IGF-1 levels increased by 35%

• Lean body mass increased measurably

• Visceral abdominal fat decreased

• Physical function was stabilized compared to placebo group which experienced measurable decline

• A separate 6-month study of sermorelin acetate in 89 adults found significant improvements in cognitive assessments including problem solving, processing speed, and working memory

Researchers noted that GHRH administration results in more physiological GH responses — pulsatile rather than prolonged elevation — and preserves the body's natural negative feedback regulation, distinguishing it from exogenous GH replacement.

Fredrick, Blackman, Corpas, Merriam, Kargi, Garcia | Endotext, National Library of Medicine | NIH | Updated March 2026

Read the full article: https://www.ncbi.nlm.nih.gov/books/NBK279163/