Hair Loss and Hormones: Understanding Testosterone, Dihydrotestosterone (DHT), and Androgens in Hair Loss

Hair loss—especially androgenetic alopecia (male and female pattern baldness)—is often blamed on hormones. While this is partly true, the real cause is not just testosterone, but a more complex interaction between androgens, testosterone, dihydrotestosterone (DHT), enzymes, and genetics.

Understanding this pathway helps patients make sense of why hair loss occurs and why certain treatments work better than others.

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What Are Androgens?

Androgens are a group of hormones responsible for male characteristics, but they are naturally present in both men and women.

Key roles of androgens:

• Development of male sexual characteristics
• Deepening of voice
• Increase in muscle mass
• Growth of body and facial hair
• Regulation of oil (sebum) production in skin

Important androgens include:

• Testosterone
• Dihydrotestosterone (DHT)
• Androstenedione
• DHEA

Among these, testosterone and DHT play the biggest role in hair loss.

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Testosterone and Hair Loss: Myth vs Fact

A common belief is that high testosterone automatically causes baldness.
👉 This is a myth.

The reality:

• Many men with high testosterone never lose hair
• Others with normal or even low testosterone develop severe baldness

Testosterone itself does not directly cause hair loss.
Its role is mainly as a precursor to DHT.

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The True Culprit: Dihydrotestosterone (DHT)

DHT (Dihydrotestosterone) is a much more potent androgen than testosterone and is the main hormonal trigger for pattern hair loss.

How is DHT formed?

1. Testosterone circulates in the body
2. An enzyme called 5-alpha reductase (5-AR) converts testosterone into DHT
3. This conversion occurs in:
   • Hair follicles
   • Scalp skin
   • Prostate

DHT is 3–5 times more powerful than testosterone in binding to androgen receptors.

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How DHT Causes Hair Loss

In genetically susceptible individuals, scalp hair follicles are hypersensitive to DHT.

Step-by-step process:

1. DHT binds to androgen receptors in scalp hair follicles
2. This triggers follicle miniaturization
3. The hair growth (anagen) phase becomes shorter
4. Each new hair grows thinner, shorter, and weaker
5. Eventually, the follicle may stop producing visible hair

➡️ The result is progressive thinning and patterned hair loss.

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Why DHT Shrinks Scalp Hair but Grows Beard Hair

This is one of the most confusing aspects of hormonal hair loss.

• Scalp hair → DHT causes thinning
• Beard & body hair → DHT stimulates growth

This happens because hair follicles in different body areas have different genetic programming and androgen receptor responses.

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Genetics: The Most Important Factor

The amount of DHT in your body is less important than how sensitive your hair follicles are to it.

• If your follicles are highly sensitive, even normal DHT levels can cause hair loss
• If they are resistant, hair may remain thick despite high hormone levels

This explains why hair loss often runs in families.

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Male vs Female Pattern Hair Loss

In Men:

• Receding hairline
• Crown thinning
• “M-shaped” hairline

In Women:

• Diffuse thinning over the crown
• Widening of the central part
• Frontal hairline usually preserved

Women may experience worsening hair loss due to:

• PCOS
• Hormonal imbalance
• Menopause
• Increased androgen sensitivity

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The Role of 5-Alpha Reductase Enzyme

There are two main types:

• Type I – Found in skin and sebaceous glands
• Type II – Found in hair follicles and prostate

Blocking this enzyme significantly reduces DHT levels, which is why many effective hair loss treatments target it.

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Treatment Implications: Targeting the Hormonal Pathway

Understanding this hormonal cycle is crucial for effective treatment.

1️⃣ 5-Alpha Reductase Inhibitors (DHT Blockers)

These target the root cause of androgenetic alopecia.

Medication	Action	Benefit
Finasteride	Blocks Type II 5-AR	Reduces scalp DHT by ~60–70%, slows hair loss
Dutasteride	Blocks Type I & II 5-AR	Reduces DHT up to ~90%, stronger effect

⚠️ These are mainly prescribed for men. They are not recommended for women of child-bearing age.

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2️⃣ Growth Stimulants (Non-Hormonal)

Medication	How it works	Who can use it
Minoxidil	Prolongs growth phase & improves follicle activity	Men & Women

Minoxidil does not block DHT, but it helps weakened follicles produce thicker hair.

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3️⃣ Anti-Androgens (Mainly for Women)

• Spironolactone – Blocks androgen receptors
• Useful in women with PCOS or hormonal imbalance

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4️⃣ Supportive & Adjunct Treatments

• Ketoconazole shampoo – Mild anti-androgen + anti-inflammatory
• Saw Palmetto / Pumpkin Seed Oil – Mild natural DHT blockers (less potent)

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Best Results Come From Combination Therapy

The most effective approach usually combines:

• DHT reduction (Finasteride / Dutasteride)
• Growth stimulation (Minoxidil)

This addresses both the cause and the consequence of hair loss.

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Key Takeaways

• Testosterone does not directly cause hair loss
• DHT is the main hormonal driver
• Genetics determines follicle sensitivity
• Both men and women can be affected
• Early treatment offers the best results

Medical Disclaimer

This article is for educational purposes only. Hair loss evaluation and treatment should be guided by a qualified dermatologist.