Thyroid & Hair Loss: Why Your Hair Is Falling Out
Thyroid disorders cause hair loss because thyroid hormone regulates hair growth cycles. Hypothyroidism causes diffuse thinning and brittle hair; hyperthyroidism causes fine, fragile hair. Hair often regrows once thyroid levels are optimized, though it takes months.
Thyroid and hair
Hair follicles are sensitive to thyroid hormone levels.
- Hypothyroidism: diffuse thinning, dry, coarse, brittle hair, often with eyebrow loss.
- Hyperthyroidism: fine, fragile hair that breaks easily.
- Regrowth takes three to six months after treatment because of hair growth cycles.
- Biotin, iron, and zinc support hair alongside thyroid treatment.
Know what your body needs, every day
PhaseBloom turns your cycle into a day-by-day plan for how to eat, move, rest, and care for your skin, so you stop guessing and start working with your hormones.
Know what your body needs, every day
PhaseBloom turns your cycle into a day-by-day plan for how to eat, move, rest, and care for your skin, so you stop guessing and start working with your hormones.
Frequently asked questions
Does thyroid hair loss grow back?
Usually, yes. Once thyroid levels are stable, hair often regrows, though it takes months because of the hair growth cycle. Nutritional support (iron, zinc) helps.
Where do you lose hair with thyroid problems?
Hair loss from thyroid is usually diffuse, meaning overall thinning rather than patches. Outer eyebrow thinning is a classic sign of hypothyroidism.