Human fingernails grow slowly. It takes about 6 months for a fingernail and up to 18 months for a toenail to grow back. Nail changes that are caused by the menopause are likely to be linked to the natural drop in oestrogen and dryness of the skin. Lower oestrogen levels brought on by the menopause can lead to dehydration and this can leave your nails brittle and weak.

Average fingernail growth rate was faster than that of toenails (3.47 vs. 1.62 mm/month, P < 0.01). Younger age, male gender, and onychophagia were associated with faster nail growth rate; however, the differences were not statistically significant. There was no significant difference between right and left fingernail/toenail growth rates.

Nail growth rate declines approximately 0.5% per year from early adulthood. Estrogen stimulates matrix cell proliferation; its decline reduces the rate of nail plate generation. Women in menopause typically notice that nails grow more slowly and that damaged nails take longer to grow out. When estrogen withdraws its support, the matrix generates thinner, less densely packed keratin fibers. The resulting nail plate has reduced tensile strength, grows more slowly, and is more susceptible to surface damage.

During menopause, declining estrogen levels reduce collagen production, leading to weaker connective tissue in the nail bed. This can result in thinner, more fragile nails that grow more slowly. Plus, reduced blood flow to the extremities (another midlife side effect) can hinder the delivery of essential nutrients to the nails.

Similarly to how oestrogen nourishes hair and skin, this beauty-promoting hormone also helps our nails grow strong and healthy. Hydrated nails are healthy nails, and oestrogen helps to keep water in body tissues. This means lower oestrogen levels can contribute to dull, yellow-ish fingernails. Our sex hormones can also affect how fast nails grow. For example, during pregnancy, where oestrogen and progesterone climb to the highest levels of a woman's lifetime, many women also experience rapid nail growth.

A telltale sign of menopause can be dry, brittle nails. Healthy fingernails must be hydrated. Since estrogens are responsible for keeping water in body tissues, lowered estrogen levels contribute to less healthy fingernails. Dehydration is also a common problem with aging, which helps explain why the elderly often have fingernails that look dull and yellow.

Studies have shown that 66% of women may experience brittle nails during menopause, which can be attributed to declining estrogen levels. As estrogen levels decline, the production of collagen and keratin, two key proteins in keratinocytes, decreases. In addition, the nail growth rate slows by 0.5% each year, starting at 25. As low estrogen levels during menopause may contribute to brittle nails, replacing this hormone through HRT can be beneficial.

Creating an estrogen deficiency in rats using ovariectomy results in a 28% decrease in collagen content in Achilles tendon. These data suggest that estrogen may increase collagen synthesis or incorporation but decrease sinew stiffness by directly inhibiting lysyl oxidase and decreasing cross-linking. In postmenopausal women, estrogen replacement therapy, which provides a daily moderate rise in estrogen, is linked with increased tendon collagen synthesis, and collagen incorporation into the patellar tendon was 47% higher in estrogen replacement therapy users compared with controls.

Yet the data are clear: a clinical study of postmenopausal women found nail involvement in 68% of participants, with manifestations including horizontal splitting and vertical ridges along the nail plate. Estrogen supports keratin synthesis, the protein that forms the nail structure. When estrogen declines, keratin decreases and the nail loses structural strength. The resulting manifestations are recognizable: nails that peel in layers or break easily, vertical ridges along the full length of the nail, dry cuticles and a tendency to hangnails, slower growth than usual.

Human toenails grow significantly more slowly than fingernails; typical estimates are that a toenail takes about 12–18 months to grow out from the matrix to the tip. Reported average toenail growth rates in healthy adults are on the order of 1–2 mm per month, compared with roughly 3 mm per month for fingernails. These rates tend to decline with age due to reduced matrix activity and peripheral blood flow.

As estrogen declines in midlife, hydration and collagen production drop. Nails may become thinner, flakier, or slower-growing — often alongside brain fog, irregular cycles, or mood swings. Estrogen, thyroid, and stress hormones all play major roles in keratin production, hydration, and blood flow — which impact nail health.

Research highlighted by Harvard's David Sinclair shows that nail growth declines by 0.5% per year after age 25, suggesting it may serve as a measurable biomarker of aging. The research, conducted by the Orentreich Foundation for the Advancement of Science, revealed that nail growth slows by approximately 0.5% per year after age 25, ultimately declining by 50% over an average human lifespan. Research shows that slow-growing or brittle nails may be linked to poor vascular health, iron deficiency, or thyroid dysfunction, while accelerated nail growth has been associated with high metabolic activity or hormonal changes.

This educational social media post on hormones and nail health states: "Estrogen helps maintain hydration and flexibility in nails by supporting collagen and keratin structure. That’s why many women notice nails becoming more brittle or dry during menopause, when estrogen levels drop." It also notes that "During pregnancy, higher hormone levels often cause faster nail growth" and that "As we age, natural hormonal changes slow down cell turnover. This can mean nails that: • Grow slower." The content links higher hormones (including estrogen) with faster nail growth and lower estrogen/aging with slower nail growth; it does not assert that lower estrogen is associated with faster toenail growth in women.