17-alpha-estradiol is a non-feminizing stereoisomer of the primary female sex hormone, 17-beta-estradiol. It has famously extended median lifespan in male mice in the NIA's Interventions Testing Program (ITP), likely by improving glucose tolerance and reducing inflammation. Crucially, it does not bind strongly to classical estrogen receptors, avoiding the hormonal side effects associated with conventional estrogen therapy.
Verdict
Promising in mice, but entirely unproven for human healthspan.
HEALTHSPAN IMPACT
Experimental
RISK LEVEL
High
EVIDENCE GRADE
C
MONTHLY COST
$50 - $150
Protocol
- Human longevity protocols are not established; animal studies use dietary administration.
Flags
- Virtually all positive evidence is from male mouse studies.
- Lacks human data for systemic use or longevity outcomes.
- Not available as a standard pharmaceutical or supplement for systemic use.
- Long-term effects of systemic administration in humans are unknown.