17a-estradiol
17a-estradiol has been studied in 11 papers since 1976: 1 trial in people, 7 in animals, 2 in cells, 1 review; 1 in the past year. It has not reached trials in people. The newest paper, Jun 19, 2026: “Geroprotective interventions preserve trabecular bone during ageing in female mice”.
“17alpha estradiol increased skin prolyl hydroxylase activity, increased soluble collagen content in the skin and increased urinary hydroxyproline excretion.”
1 of its findings points the other way.
- 8 independent labs in 6 countries
- 1 finding against
- Funders: National Institute on Aging and others
- Human trial1
- Animals7
- Cells2
What did studies of 17a-estradiol find?
23Studies of 17a-estradiol measured 23 outcomes; the most studied are IGF-1 (1 study), skin collagen (1) and cortical area fraction (1).
IGF-1
no changein mice1upin mice1
1 study
IGF-1
no changein mice1upin mice1
17a-estradiol has no effect on IGF-1 in mice.
“17α-E2 elicits no effects on IGF1 production in female mice”
Animalsfemales
17α-Estradiol Modulates IGF1 and Hepatic Gene Expression in a Sex-Specific Manner
The journals of gerontology. Series A, Biological sciences and medical sciences
17a-estradiol increases IGF-1 in mice.
“17α-E2 increases hepatic insulin-like growth factor 1 (IGF1) production in male mice without inducing any changes in pulsatile growth hormone (GH) secretion”
Animalslivermales
17α-Estradiol Modulates IGF1 and Hepatic Gene Expression in a Sex-Specific Manner
The journals of gerontology. Series A, Biological sciences and medical sciences
Skin collagen
upin humans1upin rodents1
1 study
Skin collagen
upin humans1upin rodents1
17a-estradiol improves skin collagen in rodents.
“Both steroids reverse the effect of D-penicillamine on rodent skin collagen.”
ReviewD-penicillamine-induced skin collagen changes
Research communications in chemical pathology and pharmacology
17a-estradiol increases skin collagen in humans.
“17alpha estradiol increased skin prolyl hydroxylase activity, increased soluble collagen content in the skin and increased urinary hydroxyproline excretion.”
Human trialthree to six weeksn = 5
Research communications in chemical pathology and pharmacology
Cortical area fraction
upin mice1
1 study
Cortical area fraction
upin mice1
17a-estradiol increases cortical area fraction in mice.
“Moderate increases in cortical area fraction were observed in females treated with rapamycin or 17α-estradiol at 22 months”
Animalsat lifespan-extending dosescortical bonefemales
Geroprotective interventions preserve trabecular bone during ageing in female mice
bioRxiv : the preprint server for biologyPreprint
Trabecular bone
upin mice1
1 study
Trabecular bone
upin mice1
17a-estradiol improves trabecular bone in mice.
“Bayesian modelling analysis reveals that all interventions produced responses in trabecular bone in females at 22 months. These effects were driven mainly by increases in trabecular number”
Animalsat lifespan-extending dosestrabecular bonefemales
Geroprotective interventions preserve trabecular bone during ageing in female mice
bioRxiv : the preprint server for biologyPreprint
Synapse
upin rats1
1 study
Synapse
upin rats1
17a-estradiol improves synapse in rats.
“Aging-induced elevation of neuronal cellular metabolism, stress, and reduced synapse formation-related pathways were significantly attenuated by 17α-estradiol.”
Animalsaginghypothalamusmales
eLife
Oxytocin
upin rats1
1 study
Oxytocin
upin rats1
17a-estradiol increases oxytocin in rats.
“17α-estradiol increased serum oxytocin (Oxt) and hypothalamic-pituitary-gonadal (HPG) axis activity (elevated plasma Gnrh, total testosterone; reduced estradiol).”
Animalsaginghypothalamusmales
eLife
Feminization
no changein marmosets1
1 study
Feminization
no changein marmosets1
17a-estradiol has no effect on feminization in marmosets.
“neither dose of 17α-estradiol elicited feminization in our study”
Animals0.37-0.47 or 0.62-0.72 mg/kg/dayshort treatment durationmales
GeroScience
Body mass
downin marmosets1
1 study
Body mass
downin marmosets1
17a-estradiol decreases body mass in marmosets.
“17α-estradiol treatment mildly decreased body mass, adiposity, and glycosylated hemoglobin, although these changes were not statistically significant in most instances.”
Animals0.37-0.47 or 0.62-0.72 mg/kg/dayshort treatment durationmales
GeroScience
Healthspan
upin mammals1
1 study
Healthspan
upin mammals1
17a-estradiol improves healthspan in mammals.
“17α-estradiol administration elicits health benefits in an ERα-dependent manner”
Reviewduring aging
Role of Estrogen Receptor α in Aging and Chronic Disease
Advances in geriatric medicine and research
Uterine weight
downin mice1
1 study
Uterine weight
downin mice1
17a-estradiol prevents uterine weight in mice.
“uterine weight and luminal cell thickness were decreased by OVX and prevented by 17α-E2 treatment.”
Animalsin ovariectomized micedietaryuterussix weeksfemales
17α-Estradiol prevents ovariectomy-mediated obesity and bone loss
Experimental gerontology
All 23Fewer
Funding
2 grants since 2018National Institute on AgingUS$1.8m
Role of estrogen receptor-a in aging and sex-specific responses to 17a-estradiol
National Institute on AgingOklahoma Medical Research FoundationUS$515k2021–2026
Mechanisms of metabolic, inflammatory and healthspan enhancement by 17a-estradiol
National Institute on AgingUniversity of Oklahoma Hlth Sciences CtrUS$248.4k2018–2021