Hi {{first name | there}},

Hormones are the biggest lever I've seen in longevity medicine beyond lifestyle.

Keeping your muscle. Sleeping through the night. Still wanting to have sex.

Sex hormones including estrogen, progesterone, and testosterone have a hand in all of it.

Also, your body doesn't shop in separate “his” and “hers” aisles. Each one has a role for both men and women.

Let's dive in to how this all works, and what you can do.

In the older age groups below, men's median estradiol is higher than women's. The ‘male hormone / female hormone’ labels have some explaining to do.

The charts compare U.S. adults across age groups, using public CDC NHANES measurements from 2013–2014 and 2015–2016.

Survey-weighted medians and the middle 50% of measurements, excluding known pregnancy and selected reported hormone-affecting prescriptions. Population snapshots, not individual forecasts or treatment targets. Cycle phase and blood-draw time weren't standardized; very low estradiol values include CDC's below-detection substitutions.

Women's medians are much lower in the older groups, consistent with menopause. Men's stay relatively steady here. To understand why estrogen belongs in the men's story, follow some testosterone.

Testosterone doesn't do all its work as testosterone.

Your body uses some of it directly, through androgen receptors. Some is converted by aromatase into estradiol, which signals through estrogen receptors. Change testosterone, and you can change both signals.

Conceptual pathways, not molecular structures or relative hormone amounts.

Researchers pulled these effects apart in a 16-week experiment in 400 men aged 20–50. They suppressed hormone production and varied testosterone replacement, blocking its conversion to estradiol in one cohort.

Androgen deficiency accounted for losses in lean mass, muscle size, and strength. Estrogen deficiency primarily accounted for increased body fat. Both contributed to changes in sexual function.

Estrogen is part of how testosterone works. The experiment tested induced deficiency; it didn't establish that raising either hormone above someone's needs improves aging.

Testosterone's age pattern adds another complication:

Both panels use ng/dL, with different vertical scales. These are total-testosterone measurements; free testosterone wasn't plotted.

The men's line isn't a tidy downhill slide. Longitudinal European Male Ageing Study data add context: total testosterone, free testosterone, and the binding protein SHBG changed differently. Weight changes tracked with hormone changes, too.

Two women can be the same age and at different stages of menopause. Group them by birthday, and you blur when the hormonal shift happens.

An October 12 Nature Medicine study tackled that problem using more than 300 million laboratory tests across NHANES and Israel's Clalit, including 1.3 million women in Clalit. The researchers reconstructed population patterns relative to the final period, largely from cross-sectional data.

They found shifts in 52 of 90 measures, including bone, liver, and lipid markers. Men didn't show the same pattern. Some changes, including iron-related measures, were favorable.

The authors call it a physiological “cliff.” That's a feature of reconstructed population curves, not a sudden decline in every woman or a personal prediction. Direct follow-up in SWAN supports specific changes around the final period: accelerating bone loss and sharper rises in LDL cholesterol and ApoB, while other cardiovascular risk factors changed more gradually.

Hormone-therapy users in the new study had smaller shifts in many markers. Treatment wasn't randomized; health and access-to-care differences can remain despite adjustment. That finding doesn't establish disease prevention or longer life.

This is the aging hypothesis worth testing: changing hormone signals can change how tissues maintain themselves. Restoring a signal might help preserve a function we care about. The test is what happens to people, beyond their lab results.

Start with sleep. If hot flashes and night sweats keep waking you up, treating them can change how tomorrow feels. The new ACOG guideline supports systemic hormone therapy for those symptoms and associated sleep disturbance in appropriate patients.

Then there's your skeleton, constantly being broken down and rebuilt. Estrogen helps regulate that maintenance in men, too. In a hormone-withdrawal experiment in 59 older men, estrogen was the dominant regulator preventing the measured rise in bone-breakdown markers. Both estrogen and testosterone helped maintain a bone-formation marker.

In women, the Women's Health Initiative fracture trial went beyond markers: fewer women assigned estrogen plus progestin experienced a fracture.

This tested oral conjugated equine estrogens plus medroxyprogesterone acetate in women aged 50–79. The exact result doesn't transfer to every preparation, and other health outcomes affected the regimen's overall balance of benefits and harms.

Fewer interrupted nights. Fewer fractures, which can mean less pain and time recovering. These are reasons to take hormone care seriously, and benefits to weigh against treatment risks.

But the word longevity raises one more question.

There are encouraging signals for menopausal hormone therapy started earlier.

A Cochrane review of randomized oral-therapy trials found about 30% lower relative risk of death in the subgroup starting within ten years of menopause. Blood-clot risk still increased. Overall, the review didn't find a mortality benefit.

In WHI's 18-year follow-up, overall mortality was essentially the same: 27.1% after assignment to hormone therapy versus 27.6% with placebo. Women entered at ages 50–79; assigned treatment lasted only part of that follow-up.

Timing deserves attention. The survival effect of today's transdermal estradiol and micronized progesterone combinations remains less directly established. These studies also can't tell us whether raising testosterone or estradiol extends men's lives.

One intriguing laboratory clue: 17α-estradiol extended lifespan in male mice, even when started later in life. That's a different compound from the 17β-estradiol used in standard human hormone therapy. Human life extension from that approach still needs to be demonstrated.

That's plenty of reason to care about better sleep and stronger bones. The extra-years claim still has work to do.

Keep lifting. Protect your sleep. Eat enough to support your activity. These healthy-aging basics support muscle, bone, and general health. They can help even when hormone therapy is part of your care.

For low testosterone, reversible contributors matter: obesity, sleep disorders, medication effects, and under-fueling or excessive training can be part of the picture. Addressing a cause may improve the hormone level, too.

And you don't have to earn a sleep-hygiene gold medal before asking for help with night sweats.

Formulation and history still matter. Oral and transdermal estrogen have different effects on coagulation markers. Cancer, clotting, unexplained bleeding, and liver history can change the plan. Approved and compounded products differ in their evidence and review. Nonhormonal options belong in the discussion, too.

That's the useful version of the “big lever”: keep the foundations, identify what you want to improve, and choose care around the evidence for that goal.

Next week, we'll follow the testosterone story into replacement, enclomiphene, and fertility in more detail.

Explore hormone-care evaluation

A licensed clinician determines eligibility and treatment fit. Enclomiphene is not FDA-approved; the estrogen research above doesn't establish it as a longevity therapy.

I'm a co-founder of Curator, which operates these care pages. Purchases through my page may support my work and this Letter.

Hillary Lin, MD

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This Letter is for education, not personal treatment advice.