Is 17-alpha-estradiol legal in the United States?

In male mice, it has made them live longer again and again, even at higher doses and even when started late in life. It does nothing for female mice, and nobody knows why.

This is one of the strongest drug results for lifespan anywhere. It comes with a catch so big that most coverage leaves it out.

How it works: It is the mirror-image form of normal estradiol. That small flip makes it far weaker at the usual estrogen receptors, so it loses the feminising effects.

Approval history: Not approved in the United States for any use. Some European countries sell it as a scalp treatment for pattern hair loss. That is a different use, a different way of taking it and a different dose from the lifespan studies.

Approves prescription drugs, each for a named use. It also acts against unapproved products, including peptides sold online. Compounding pharmacies, which mix drugs to order, may make some compounds with a prescription. That only applies when the FDA puts the compound in a category of bulk ingredients it allows.

The legal category above is how The Longevity Archive reads U.S. Food and Drug Administration listings for 17-alpha-estradiol on the reviewed date. It is not a legal opinion. Rules change. Bringing a compound into the country, prescribing it and owning it can each be treated differently. Check with the agency before you act on anything here.

Check FDA directly

Whether 17-alpha-estradiol is banned in sport is set by the World Anti-Doping Code and by military rules, not by its legal status in the United States. Before you compete or get tested, look up 17-alpha-estradiol by name on the Prohibited List, or look up a named product in Global DRO. Under the World Anti-Doping Code, category S0 bans, at all times, any drug-like substance that meets two tests. No other section of the List covers it. And no government health regulator anywhere has a current approval for it as a treatment in people. Many substances that are approved somewhere are banned by name in another section. So approval does not mean a substance is allowed in sport.

• WADA Prohibited List
• Global DRO (check a named product)
• USADA (US athletes)
• Operation Supplement Safety (US service members)

The rules you compete or serve under decide this, not this page.