Have you noticed more hair in your hairbrush or shower? Perhaps your ponytail feels thinner, your parting is becoming wider, or your hair simply doesn’t have the fullness it once did.

Hair thinning is a concern I am hearing more frequently from women, particularly those approaching or going through menopause.

We often blame aging, stress, or declining estrogen. But what if our hair is also telling us something about our blood sugar and metabolic health?

Last month, we explored the connection between cholesterol, blood sugar, and metabolic dysfunction. This month, let’s look at how these same factors may also influence our hair.

Healthy Hair Starts Beneath the Scalp
Hair follicles are among the most active structures in our body. They need a steady supply of energy, oxygen, and nutrients to grow healthy hair.

Each hair goes through a natural cycle of growing, resting, and shedding. When this cycle is disrupted, we may notice more hair falling out or less hair growing back.

Hormones and genetics play an important role, but research suggests that insulin resistance and inflammation may also contribute to certain types of hair thinning.

What Does Insulin Have to Do With Hair Loss?
Most of us associate insulin with blood sugar and diabetes. But insulin also influences our hormones.

When we eat, insulin helps move sugar from our blood into our cells, where it is used for energy.

Sometimes, our cells stop responding to insulin as efficiently as they should. To compensate, our body produces more insulin. This is called insulin resistance.

Higher insulin levels can influence hormones called androgens, including testosterone. In women who are sensitive to these hormones, this may contribute to thinning hair, particularly around the crown.

We see this connection clearly in some women with polycystic ovary syndrome (PCOS).

During menopause, declining estrogen and changes in insulin sensitivity may occur together, making hair thinning more noticeable in women who are already susceptible.

This doesn’t mean insulin resistance causes every case of hair loss, but it may be one contributing factor worth investigating.

Can Your Blood Sugar Be Normal While Your Insulin Is High?
Surprisingly, yes.

Your fasting blood sugar may be perfectly normal because your body is producing more insulin to keep it that way.

This is why looking at blood sugar alone doesn’t always tell us the full story.

When investigating hair thinning, some useful blood markers to consider include:

• Fasting glucose: Measures your blood sugar after an overnight fast.
• HbA1c: Shows your average blood sugar over approximately three months.
• Fasting insulin: Helps us understand how much insulin is circulating in the blood while fasting.
• HOMA-IR: Uses fasting glucose and insulin to estimate insulin resistance.
• hs-CRP: Helps identify inflammation in the body.
• Full Thyroid Panel: TSH, Free T4, Free T3, Reverse T3, Thyroid Peroxidase Antibodies (TPOAb), and Thyroglobulin Antibodies (TgAb).

Not everyone needs all these tests. The choice depends on symptoms, medical history, and the type of hair loss.

Long-term high blood sugar can also affect the health of our small blood vessels, which help deliver oxygen and nutrients throughout the body, including to the scalp.

Why Menopause Matters
Estrogen helps influence the normal hair growth cycle. As estrogen levels decline during menopause, some women notice their hair becoming finer or thinner, particularly around the parting and crown.

At the same time, changes in body composition, blood sugar regulation, and hormone balance may occur.

But menopause isn’t always the only explanation.

Thyroid problems, nutritional deficiencies, stress, illness, and rapid weight loss can also contribute to hair shedding.

Thyroid-related hair loss often causes more general thinning across the scalp, whereas female-pattern hair loss commonly affects the parting and crown.

This is why it’s important to understand what is actually causing the hair loss rather than assuming it’s simply part of getting older.

What Can We Do to Support Healthy Hair?
The good news is that many of the habits that support healthy blood sugar also support our overall health.

Eat balanced meals. Include enough protein, vegetables, healthy fats, and fiber. Reduce excessive sugar and refined carbohydrates.

Keep moving. Walking and resistance training help our muscles use glucose more efficiently and improve insulin sensitivity.

Prioritize sleep. Poor sleep can affect blood sugar regulation and hormone balance.

Manage stress. Chronic stress can affect our metabolism and may also trigger excessive hair shedding.

Pay attention to gut health. Digestive problems can sometimes interfere with the absorption of nutrients needed for healthy hair.

And importantly, avoid restrictive diets and rapid weight loss, which can sometimes make hair shedding worse.

Could Nutritional Deficiencies Be Affecting Your Hair?
Hair growth also depends on getting enough of the right nutrients. Low iron, zinc, vitamin D, vitamin B12, or folate may contribute to hair problems in some women. Eating too little protein, following a restrictive diet, or having difficulty absorbing nutrients can also affect hair health.

Rather than taking several hair supplements without knowing what you need, it is better to review your diet and investigate possible deficiencies when appropriate. Too much of certain nutrients can actually worsen hair loss.

Looking Beyond the Hair
When investigating hair thinning, I believe it’s important to look at the whole picture.

Rather than immediately turning to another shampoo, serum, or supplement, we should ask what might be contributing to the problem.

Could there be hormonal changes, insulin resistance, thyroid dysfunction, or nutritional deficiencies?

A careful health history and appropriate blood tests can help identify possible causes. A dermatologist can also determine the type of hair loss and whether specific treatment is needed.

The goal isn’t simply to have blood results that fall within a laboratory range. It’s to understand what those results mean in the context of your overall health.

A Small Step You Can Take Today
If you’ve noticed your hair becoming thinner, don’t immediately assume it’s simply part of aging or menopause.

Start by asking yourself a few questions:

• Has my hair been gradually thinning, or am I suddenly shedding more than usual?:
• Have I noticed changes in my energy, sleep, stress levels, or weight?:
• When was the last time I had my thyroid function, blood sugar, and nutritional health assessed?:

Your first step: Pay attention to when your hair thinning began and any other changes you may have noticed in your health. These details can help guide a more meaningful investigation.

Remember, hair loss can have several causes, and understanding what’s contributing to it is often more useful than simply reaching for another supplement.

If you’re concerned about persistent hair thinning, a personalized Functional Medicine consultation can help you explore possible metabolic, hormonal, and nutritional contributors, alongside appropriate medical assessment.

Coming Next Month: Iron and Ferritin
Did you know that your hemoglobin can be normal even when your body’s iron stores are running low?

Low iron stores can sometimes contribute to hair shedding, fatigue, and reduced energy, even before anemia develops.

In December, we’ll explore the difference between iron deficiency and anemia, what ferritin tells us, and why a normal blood count doesn’t always tell the whole story.

Always looking out for you,


Small changes for a healthier “U”

References

1. Rosenfield RL, Ehrmann DA. The Pathogenesis of Polycystic Ovary Syndrome. Endocrine Reviews. 2016.

2. Vujovic A, Del Marmol V. The Female Pattern Hair Loss: Review of Etiopathogenesis and Diagnosis. BioMed Research International. 2014.

3. Malkud S. Telogen Effluvium: A Review. Journal of Clinical and Diagnostic Research. 2015.

4. Almohanna HM, et al. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatology and Therapy. 2019.

5. American Academy of Dermatology Association. Hair Loss: Diagnosis and Treatment.