Growth hormone sex differences are an important feature of human endocrine physiology. Although growth hormone (GH) performs similar fundamental functions in males and females, its secretion patterns, hormonal regulation and downstream effects are not identical.
Studies of the GH–IGF-1 axis reveal differences in circulating GH concentrations, secretory pulse characteristics and hepatic responsiveness. Oestrogen and testosterone contribute to these patterns, but age, adiposity and nutritional status also influence the results.
7 Research Findings About Growth Hormone Sex Differences
1. Women Generally Have Higher Average GH Concentrations
Studies measuring GH throughout the day have reported higher average circulating GH concentrations in premenopausal women than in similarly aged men.
This does not necessarily indicate greater growth hormone activity in every tissue.
GH concentrations fluctuate substantially, making single blood measurements unsuitable for characterising overall secretion.
2. GH Secretory Patterns Differ Between Men and Women
Human studies have identified differences in the organisation of GH pulses.
In one investigation, young men exhibited prominent nocturnal pulses, whereas women showed a more distributed pattern of secretion.
Other studies have attributed differences in overall GH output to secretory pulse amplitude rather than consistently greater pulse frequency.
These findings demonstrate why sampling methods and study populations matter.
3. Oestrogen Influences GH Regulation
Oestrogen participates in the regulation of the GH–IGF-1 axis.
However, its effects depend on the tissue involved, hormonal environment and route of exposure.
Experimental findings do not support treating oestrogen as a simple, universally acting GH stimulant.
4. Oral Oestrogen Can Reduce Hepatic IGF-1 Production
One of the clearest findings concerns the liver.
Oral oestrogen undergoes substantial first-pass hepatic exposure, which can reduce the liver’s responsiveness to GH and lower circulating IGF-1.
Reduced IGF-1 feedback may subsequently increase GH secretion.
This creates a situation in which higher circulating GH accompanies lower IGF-1 production.
5. Transdermal Oestrogen Produces Different GH-Axis Effects
Studies comparing oral and transdermal oestrogen have demonstrated different endocrine responses.
Unlike oral administration, transdermal oestrogen generally avoids the same degree of first-pass hepatic exposure.
Consequently, it does not produce the same characteristic suppression of hepatic IGF-1 production.
These findings illustrate the importance of distinguishing circulating hormone concentrations from tissue-specific hormone action.
6. Testosterone Also Contributes to GH Regulation
Testosterone interacts with the GH axis through several mechanisms.
Research indicates that some testosterone-related stimulation of GH secretion depends on conversion to oestradiol through aromatase activity.
Androgens can also influence peripheral GH responsiveness.
The interaction therefore involves both central endocrine regulation and tissue-specific signalling.
7. Sex Differences Complicate GH and IGF-1 Interpretation
GH-axis studies should account for age, sex steroid status, body composition and relevant hormonal exposures.
An identical circulating GH concentration does not necessarily represent identical endocrine activity in two participants.
Similarly, differences in IGF-1 may reflect hepatic responsiveness rather than GH secretion alone.
Why These Differences Matter in Research
The distinction between GH secretion and GH action is particularly important when comparing endocrine measurements.
Our growth hormone and IGF-1 research guide explains the relationship between these hormones.
For additional context, see our articles on growth hormone pulsatility and growth hormone and ageing.
Laboratories exploring peptide signalling and endocrine pathways can also visit Peptide Lab Direct UK, our featured UK research peptide supplier, for research compounds associated with growth hormone and related molecular pathways.
Frequently Asked Questions
Do women produce more growth hormone than men?
Many studies report higher average circulating GH concentrations in premenopausal women, although individual variation is substantial.
Are growth hormone pulses different between sexes?
Yes. Studies have identified differences in secretory patterns, pulse amplitude and feedback regulation.
Does oestrogen increase growth hormone?
Its effects depend on the hormonal environment and route of exposure. Oral oestrogen can increase circulating GH indirectly by reducing IGF-1 feedback.
Why can oral oestrogen lower IGF-1?
First-pass hepatic exposure can reduce GH-stimulated IGF-1 production.
Does testosterone influence growth hormone secretion?
Yes. Some effects involve the conversion of testosterone to oestradiol.
Should GH and IGF-1 research account for sex differences?
Yes. Sex steroid status and tissue responsiveness can materially influence endocrine measurements.
Scientific References
- Veldhuis JD et al. Regulatory mechanisms of growth hormone secretion are sexually dimorphic. Journal of Clinical Investigation, 1998. https://pmc.ncbi.nlm.nih.gov/articles/PMC509077/
- Ho KKY. Managing Estrogen Therapy in the Pituitary Patient. Journal of the Endocrine Society, 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC10153416/
- Normal Physiology of Growth Hormone in Normal Adults. Endotext, NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK279056/
- Mechanisms in Endocrinology: Paracrine and endocrine control of the growth hormone axis by estrogen. European Journal of Endocrinology, 2021. https://pubmed.ncbi.nlm.nih.gov/33852424/
For laboratory research only. Not intended for human administration or clinical use.
