Thyroid and Eyebrow Loss: The Outer-Third Sign

Quick answer: Losing the outer third of your eyebrows is a classic sign of an underactive thyroid (hypothyroidism), because low thyroid hormone slows hair growth. If you notice this along with fatigue, weight changes, or feeling cold, ask your doctor for a simple thyroid blood test. Treating the cause can help regrowth, and a stamp keeps brows full in the meantime.

Why the thyroid affects eyebrows

Thyroid hormone regulates the hair-growth cycle. When it's low, hairs — including the outer brow — shed and regrow slowly. The outer third is often affected first.

What to do

• See your doctor for a thyroid check if you notice the outer-third loss plus other symptoms.
• Support regrowth with nutrition — see grow brows back.
• Fill the gap now — a stamp rebuilds the outer brow. See filling gaps.

Frequently asked questions

Does losing the ends of eyebrows mean thyroid problems?

It can — outer-third eyebrow loss is a recognized sign of an underactive thyroid, so it's worth a test.

Will eyebrows grow back after thyroid treatment?

Often they improve once thyroid levels are corrected, though it can take months.

How do I fill in a missing brow tail?

Use soft powder or a stamp to rebuild the outer third in a natural shape.

Related reading: Why brows get thin · Menopause & brows · Fill eyebrow gaps

Rebuild a sparse brow tail in seconds — the Browvana Eyebrow Stamp Kit. (This is general information, not medical advice — please see your doctor about symptoms.)