How Lash Health Connects to Iron Deficiency, Thyroid Imbalance and Stress According to Experts

We all want full, healthy lashes. But if yours are thinning, falling out, or refusing to grow — even with serums — the real issue might not be cosmetic. According to health experts, internal factors like iron levels, thyroid function and chronic stress can seriously impact lash health.

At Nuur Cosmetics, our formulas are developed using scientific principles, but lash health is much deeper than just what you apply externally. This blog explores the medical side of lash loss, helping you understand what's really going on — and what to do next.

1. Iron Deficiency May Affect Lash Growth

Iron is essential for oxygen delivery to cells — including those that support healthy hair and lash follicles. When iron is low, your body prioritises vital organs over non-essential systems like hair growth.

Possible signs of low iron impacting lashes:

• Increased lash fallout, especially after removing mascara

• Slower lash regrowth

• Thinner or shorter lashes over time

• Lash fragility or breakage

According to the Cleveland Clinic, iron deficiency anemia affects millions of women globally, and one early symptom is hair loss, including eyebrows and lashes. If you’re noticing more lash fallout than usual, it may be worth asking your GP to test your ferritin levels, not just basic iron.

2. Thyroid Hormones and Lash Health

The thyroid gland helps regulate metabolism, energy, and hair growth. Both underactive (hypothyroidism) and overactive (hyperthyroidism) thyroid conditions can interfere with the natural hair cycle — and that includes your eyelashes.

Lash-related signs of thyroid imbalance:

• Sparse outer third of eyelashes or eyebrows

• Lash breakage and brittleness

• Slower-than-usual lash regrowth

• Dry eyelids or eye irritation

The British Thyroid Foundation recognises hair and lash loss as a lesser-known symptom of thyroid disorders. Since these issues often develop gradually, many people don’t make the connection right away. A simple thyroid panel (TSH, T3, T4) from your GP can provide insight.

3. Stress and Its Surprising Impact on Lashes

Stress is a known trigger for hair loss through a process called telogen effluvium, where hair prematurely enters its resting phase. When chronic stress takes over, lash follicles can "shut down" temporarily, slowing growth or even triggering shedding.

Signs your lashes are affected by stress:

• Sudden lash shedding or gaps in the lash line

• Delayed regrowth after lash lifts or extensions

• Shorter, thinner lashes without any product changes

Scientific studies have shown that elevated cortisol levels can disturb the hair growth cycle. While your lashes may recover once stress levels drop, repeated high-stress periods can lead to longer-term thinning. Pair this with poor sleep or nutritional depletion, and lash health suffers.

What Can You Do? A Holistic Approach to Lash Confidence

It’s easy to overlook internal factors when dealing with lash problems. But addressing the root cause can help you see better, longer-lasting results from your lash routine.

✅ Prioritise your internal health:

• Ask your doctor about testing iron (especially ferritin), thyroid hormones, B12 and vitamin D

• Track changes in energy, stress, menstrual cycles and lash fallout

✅ Be gentle on your lashes:

• Avoid harsh rubbing or waterproof mascaras unless using gentle formulas

• Consider switching to tubing mascaras that remove with water, like our Nuur Lash Tubing Mascara

✅ Use a lash serum designed for sensitive eyes:

At Nuur, we developed our lash serum using scientific research into peptides and biotin — no prostaglandins, no harmful preservatives.
It’s formulated for long-term lash support and sensitive eyes, although it is not yet clinically tested.

✅ Support your lashes through wellness:

• Reduce daily stress with breathwork, sleep, and routines

• Support your body with balanced nutrition and rest — that’s when your lashes regenerate most

Your Lash Line Might Be Telling You Something Deeper

Nuur Lash was born from a desire to create a gentler, smarter alternative to hormone-based lash serums. While external products help, we encourage every customer to look within — because beautiful lashes often reflect your inner health.

When in doubt, start with self-care and science-backed habits. We're here for the rest.