Growth Hormone Replacement Changes Brain Chemistry — First Direct Evidence
One month of GH replacement in deficient adults changed CSF levels of GH, IGF-1, monoamine metabolites, neuropeptides, and opioid peptides.
Quick Facts
What This Study Found
One month of GH replacement increased CSF GH and IGF-1 while altering monoamine metabolites, neuropeptides, and opioid peptide concentrations.
Key Numbers
How They Did This
Double-blind, placebo-controlled trial in 20 adults with GH deficiency (10 per group). CSF collected before and after 1 month of treatment (0.25 U/kg/week). Measured GH, IGF-1, IGFBP-3, monoamine metabolites, neuropeptides, and opioid peptides.
Why This Research Matters
GH-deficient adults report improved mood, energy, and cognition on GH replacement. This study provides the first direct evidence that GH treatment changes brain chemistry, offering a biological explanation for these improvements.
The Bigger Picture
GH-deficient patients report improved mood, energy, and cognition on replacement therapy. This study provides a biological explanation: GH treatment actually changes the brain's chemical environment.
What This Study Doesn't Tell Us
Small study (10 per group). Only 1 month of treatment. CSF sampling is invasive and may have affected some measurements. Long-term brain chemistry effects unknown.
Questions This Raises
- ?Which specific opioid peptide changes correlate with mood improvement?
- ?Do the brain chemistry changes persist long-term?
Trust & Context
- Key Stat:
- Placebo-controlled proof Double-blind trial showing GH replacement directly changes brain opioid peptides, neurotransmitters, and growth factors
- Evidence Grade:
- Strong — double-blind, placebo-controlled RCT with direct CSF measurement. Gold-standard design despite small size.
- Study Age:
- Published in 1995 (31 years ago). GH replacement's neurological benefits are now well-recognized.
- Original Title:
- Treatment of growth hormone-deficient adults with recombinant human growth hormone increases the concentration of growth hormone in the cerebrospinal fluid and affects neurotransmitters.
- Published In:
- Neuroendocrinology, 61(1), 57-66 (1995)
- Authors:
- Johansson, J O, Larson, G, Andersson, M, Elmgren, A, Hynsjö, L, Lindahl, A, Lundberg, P A, Isaksson, O G, Lindstedt, S, Bengtsson, B A
- Database ID:
- RPEP-00324
Evidence Hierarchy
Frequently Asked Questions
Does growth hormone affect the brain?
Yes — this study directly proved it. GH replacement increased brain GH and IGF-1 levels and changed neurotransmitter and opioid peptide concentrations in the cerebrospinal fluid.
Why do GH-deficient patients feel better on replacement?
This study suggests it's because GH treatment changes brain chemistry — altering monoamine neurotransmitters (affecting mood), neuropeptides (affecting stress response), and opioid peptides (affecting pain and well-being).
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-00324APA
Johansson, J O; Larson, G; Andersson, M; Elmgren, A; Hynsjö, L; Lindahl, A; Lundberg, P A; Isaksson, O G; Lindstedt, S; Bengtsson, B A. (1995). Treatment of growth hormone-deficient adults with recombinant human growth hormone increases the concentration of growth hormone in the cerebrospinal fluid and affects neurotransmitters.. Neuroendocrinology, 61(1), 57-66.
MLA
Johansson, J O, et al. "Treatment of growth hormone-deficient adults with recombinant human growth hormone increases the concentration of growth hormone in the cerebrospinal fluid and affects neurotransmitters.." Neuroendocrinology, 1995.
RethinkPeptides
RethinkPeptides Research Database. "Treatment of growth hormone-deficient adults with recombinan..." RPEP-00324. Retrieved from https://rethinkpeptides.com/research/johansson-1995-treatment-of-growth-hormonedeficient
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.