Hair Loss: Understanding the Root Causes and What Your Body May Be Telling You

If you’re noticing more hair shedding, thinning at your part, or a change in your hair texture, it’s natural to wonder what’s going on.

One of the most important things to understand is this: hair loss is often a signal from your body—not just a hair problem, but a hormone and whole-body issue.

Your hair follicles are highly sensitive to your internal environment. When your hormones shift—whether from stress, metabolism, thyroid changes, or life stages like menopause—your hair growth cycle can be disrupted.

But here’s the key:
👉 Hormone imbalances rarely happen on their own. There is almost always a deeper root cause driving them.

Let’s walk through both the hormones involved and what may be causing them to become imbalanced.

The Main Hormones That Affect Your Hair

1. Androgens (Testosterone, DHT)

These are often called “male hormones,” but you have them as a woman too.

Testosterone can be converted to DHT in the hair follicles. When DHT androgens are too high—or when your hair follicles are more sensitive to them—they can:

• Shrink hair follicles 
• Shorten the hair growth phase 
• Lead to thinning at the crown or widening of your part 

This is known as androgenetic alopecia (pattern hair loss) (Owecka et al., 2024; Sennett & Garza, 2021).

Interestingly, your DHT blood levels may be normal. The issue can be increased sensitivity within the hair follicle itself (Carmina et al., 2019; Grymowicz et al., 2020).

What drives high androgens?

• Polycystic ovary syndrome (PCOS) – often linked to insulin resistance (Viquez et al., 2025; Carmina et al., 2019; Hasan et al., 2022) 
• Insulin resistance and metabolic health issues – high insulin stimulates more androgen production (Chen et al., 2022; Sennett & Garza, 2021) 
• Adrenal conditions (e.g., non-classic congenital adrenal hyperplasia) (Hasan et al., 2022; Vinay et al., 2018) 
• Rare tumors of the ovaries or adrenals (Hasan et al., 2022) 
• Genetics – increased sensitivity of hair follicles to DHT (Owecka et al., 2024; Trüeb, 2021) 

👉 However, even if you have a genetic predisposition, you can still influence your scalp DHT production and sensitivity. Your diet, metabolism, inflammation levels, and even your scalp environment can all influence how strongly DHT affects your hair follicles.

What Is DHT and Why Does It Matter?

DHT is made from testosterone through an enzyme called 5-alpha reductase, which is active in your hair follicles. Everyone has this enzyme, but it tends to be more active in areas of the scalp where hair thinning occurs (Takayasu & Adachi, 1972; Trüeb, 2002; Owecka et al., 2024).

When DHT levels or sensitivity are higher in the scalp, hair follicles can gradually shrink over time. This leads to thinner, shorter hairs and eventually less visible hair.

How Your Diet and Metabolism Play a Role

Even though research directly measuring DHT changes in the scalp is limited, we do know that your overall metabolic health can influence the environment in which DHT acts.

1. High Sugar and “Western” Diet Patterns

A diet high in sugar and ultra-processed foods may:

• Disrupt blood glucose control
• Lower sex hormone-binding globulin (SHBG)
• Increase “free” (active) testosterone
• Shift the balance toward more DHT activity

(Sadgrove, 2021; Sadgrove et al., 2023)

This doesn’t necessarily mean your body makes dramatically more DHT, but it may increase the impact DHT has on your hair follicles.

2. Insulin Resistance

If your body is resistant to insulin (a common issue with high sugar intake and stress), this may:

• Affect small blood vessels supplying hair follicles
• Contribute to inflammation
• Support conditions that promote hair follicle shrinkage

(Matilainen & Keinänen-Kiukaanniemi, 2002; Kash et al., 2021)

3. Magnesium and Nutrient Status

Low magnesium levels may:

• Worsen insulin resistance
• Affect hormone metabolism
• Potentially increase physical tension in the scalp

(Sadgrove, 2021)

This highlights how even basic nutrients can influence your hair health indirectly.

What’s Happening in the Scalp Itself?

Hair loss is not just about hormones. It’s also about the local environment of your scalp.

In thinning areas, researchers have found:

• Increased oil (sebum) production
• Overactive fat metabolism (PPAR-γ activity)
• Changes in bacteria and yeast on the scalp
• Increased levels of inflammatory signals like PGD2

(Sadgrove et al., 2023; Kash et al., 2021)

These factors can amplify how DHT affects your follicles, even if hormone levels in your blood look normal.

The Role of Inflammation and Oxidative Stress

Hair thinning is often associated with:

• Chronic low-grade inflammation
• Oxidative stress (cell damage from free radicals)
• Changes in the scalp microbiome

(Kash et al., 2021; Shi et al., 2025)

This means your hair health is closely tied to your overall inflammatory state, not just hormones alone.

Hormones That Can Counterbalance DHT

Your body has natural ways to balance DHT:

• Progesterone can reduce the conversion of testosterone to DHT
• Estrogen can shift testosterone toward other pathways

(Grymowicz et al., 2020)

This is one reason hormonal balance, especially in women, plays such an important role in hair health.

What May Help Reduce DHT Impact

While research is still evolving, several strategies may support a healthier scalp environment:

• Eating a lower-glycemic, whole-food diet
• Improving blood sugar balance
• Ensuring adequate magnesium intake
• Using certain plant-based compounds that may reduce 5-alpha reductase activity
• Lowering scalp inflammation by addressing chronic inflammation
• Low-level light therapy, which may influence enzyme activity in the scalp

(Sadgrove, 2021; Khantham et al., 2021; Dhariwala & Ravikumar, 2019; Shi et al., 2025)

These approaches don’t “block DHT” directly in a medical sense, but they may reduce the conditions that allow DHT to have a stronger effect.

2. Estrogen (Low or Fluctuating Levels)

Estrogen helps keep your hair in the growth phase longer and supports thickness.

When estrogen drops, you may notice:

• Increased shedding
  
• Thinner hair strands
  
• Reduced overall volume
  

This is common during:

• Perimenopause and menopause (Gupta et al., 2025; Owecka et al., 2024)
  
• Postpartum period
  
• Stopping hormone therapy
  

Rapid drops in estrogen can trigger telogen effluvium, where many hairs shift into shedding at once (Viquez et al., 2025; Trüeb, 2010).

What causes low estrogen?

• Natural, surgical or medication induced menopause or perimenopause (Sowińska et al., 2025; Carmina et al., 2019)
  
• Premature ovarian insufficiency (Owecka et al., 2024)
  
• Postpartum hormone shifts (Wolff et al., 2016)
  
• Anti-estrogen medications (e.g., aromatase inhibitors) (Carmina et al., 2019)
  

👉 This is why hair changes are so common during major life transitions.

3. Thyroid Hormones

Your thyroid controls your metabolism—and your hair growth cycle depends on it.

Both low and high thyroid function can cause hair loss:

• Low thyroid (hypothyroidism):

• Dry, coarse, brittle hair
  
• Diffuse thinning

   

• High thyroid (hyperthyroidism):

• Fine, soft hair
  
• Increased shedding
  

(Hussein et al., 2023; Natarelli et al., 2023)

What causes thyroid-related hair loss?

• Autoimmune thyroid disease (most common) (Lin et al., 2016; Hussein et al., 2023)
  
• Medications or thyroid treatments (Lin et al., 2016)
  
• Iodine imbalance (too much or too little) (Hussein et al., 2023)
  

👉 Thyroid issues are one of the most important and often overlooked causes of diffuse hair loss.

4. Stress Hormones (Cortisol)

Chronic stress can directly affect your hair.

When cortisol stays elevated, it pushes your hair follicles into a resting phase, leading to shedding (Hasan et al., 2022).

What drives this?

• Chronic stress
  
• Poor sleep
  
• Illness or trauma
  
• Overtraining
  

(Owecka et al., 2024; Natarelli et al., 2023)

👉 This is why you may notice hair loss a few months after a stressful period.

5. Prolactin

High prolactin levels can contribute to hair shedding and sometimes unwanted hair growth elsewhere (Grymowicz et al., 2020).

Common causes:

• Pituitary tumors (prolactinoma) (Carmina et al., 2019)
  
• Hypothyroidism (Vinay et al., 2018)
  
• Certain medications (Lin et al., 2016)
  

6. Growth Hormone (GH / IGF-1)

These hormones help support healthy hair growth.

Low levels can lead to:

• Thin, sparse hair
  

(Sowińska et al., 2025)

The Bigger Picture: Root Causes That Affect Multiple Hormones

Here’s where it all comes together.

Most people don’t have just one hormone imbalance—they have upstream drivers affecting multiple systems at once.

Common root drivers include:

1. Metabolic Health & Insulin Resistance

• Drives DHT androgen excess
  
• Common in PCOS
  
• Linked to hair thinning patterns
  

(Chen et al., 2022; Viquez et al., 2025)

2. Nutrient Deficiencies

Low levels of:

• Iron
  
• Zinc
  
• Vitamin D
• Magnesium
  

Can disrupt hormone balance and hair growth (Owecka et al., 2024; Sowińska et al., 2025).

3. Chronic Stress & Poor Sleep

• Disrupts cortisol
  
• Affects thyroid and sex hormones
  
• Pushes hair into shedding
  

(Wolff et al., 2016; Natarelli et al., 2023)

4. Autoimmune & Inflammatory Conditions

• Can affect thyroid, ovaries, and other glands
  
• Often linked to hair loss
  

(Lin et al., 2016; Dakkak et al., 2024)

5. Medications & Toxins

Some medications can:

• Disrupt hormone production
  
• Directly affect hair follicles
  

Examples include chemotherapy, retinoids, and certain hormonal medications (Lin et al., 2016).

6. Genetics

Your genes influence:

• Hormone production
  
• Hair follicle sensitivity
  
• Risk of pattern hair loss
  

(Trüeb, 2021; Redler et al., 2017)

When Should You Look Deeper?

You may want to explore root causes if your hair loss is:

• Sudden or excessive
  
• Diffuse (all over your scalp)
  
• Accompanied by fatigue, weight changes, or cycle changes
  
• Associated with acne or facial hair
  

A targeted work-up may include:

• Androgens (testosterone, DHEAS)
  
• Thyroid panel (TSH, T3, T4)
  
• Prolactin
  
• Cortisol
  

But most importantly—

👉 Looking upstream at metabolism, stress, nutrition, lifestyle, scalp toxins and inflammation is key.

The Takeaway

Hair loss is not just about your hair.

It’s often a reflection of:

• Hormonal balance
  
• Metabolic health
  
• Stress levels
  
• Nutrient status
• Inflammation
  

When you address the root causes, you’re not just supporting your hair—you’re supporting your entire body.

Understanding these root causes can also help guide a more personalized approach to supporting hair health.

✨ Want more tools for strong, healthy hair?

Check out my Healthy Hair Playlist on YouTube for deep dives into how to reduce inflammation-related hair loss, recover from nutrient deficiencies that cause hair shedding, hair-growth supplements, and more.