How Testosterone Converts to DHT Inside the Hair Follicle

Dihydrotestosterone (DHT) is a stronger form of testosterone that is made when an enzyme called 5-alpha-reductase changes some testosterone into DHT. It plays a role in several functions in the body, but in people with DHT-sensitive hair follicles, it can gradually affect how those follicles produce hair.

The important factor is therefore how a person's hair follicles respond to DHT. Some follicles are more sensitive to its effects, which can gradually make the hair they produce finer and shorter.

How Does DHT Affect Sensitive Hair Follicles?

DHT can gradually change the way sensitive hair follicles produce hair, so each new strand may become shorter and finer over several growth cycles. This gradual change is called miniaturisation. That means, a hair follicle that once produced a thick strand may gradually produce a finer one.

You can notice the following changes build over time if you have sensitive hair follicles:

• A shorter period of active hair growth

• A gradual reduction in follicle size

• Finer strands with each new growth cycle

• Less visible hair density in the affected area

Why Does DHT Affect Some Parts of the Scalp More Than Others?

DHT-related thinning commonly affects the temples, hairline, and crown because the follicles in these areas can be more sensitive to DHT. The follicles at the back and sides of the scalp are generally less affected.

This difference in DHT sensitivity can create a recognisable pattern of hair thinning along these areas:

• Temples and hairline: Hair may gradually become finer or move backwards.

• Crown: Hair can become thinner, and the scalp may become easier to see.

• Back and sides: Hair usually remains denser because these follicles are less sensitive to DHT.

Note: The exact pattern of hair thinning varies from person to person. The difference is not simply about how much DHT is present in one part of the scalp. The way individual follicles respond to DHT is also important.

What Determines How Hair Follicles Respond to DHT?

Genetics is one of the main factors that determines how strongly a person's hair follicles respond to DHT. This is why two people with similar hormone levels can have very different patterns of hair thinning.

Several other factors can determine how you hair follicles respond to DHT:

• Level of the enzyme, 5-alpha reductase: Individuals with higher levels of this enzyme will convert more testosterone to DHT in their scalp.
  

• Hormonal changes with age: Changes to the endocrine system with age can also change the response of the follicle to androgens.
  

• Use of external androgens: This may increase internal levels of androgen in some individuals and can have an effect on the follicles that are sensitive to DHT.

Does Having High DHT Always Cause Pattern Thinning?

No, having high DHT does not automatically mean that a person will develop pattern thinning. Hair follicle sensitivity plays an important role, so hormone levels alone do not tell the whole story.

The phrase ‘high DHT’ can therefore be misleading when used as the only explanation for pattern thinning. Someone can have typical hormone levels and still have follicles that are particularly sensitive to DHT.

How Is DHT-Related Thinning Different From Other Types of Hair Fall?

DHT-related thinning usually develops gradually in a specific pattern, while other types of hair fall may cause more noticeable shedding across the scalp. The location, speed, and appearance of the hair thinning can help you understand the difference between different hair fall types:

Can Testosterone and DHT Affect Hair in Women?

Yes, testosterone and DHT can affect hair in women, particularly when some scalp follicles are sensitive to DHT. Women naturally produce testosterone (lower than men), and some of it is converted into DHT in the body. The effect on hair depends less on testosterone itself and more on how sensitive individual hair follicles are to DHT.

In women with DHT-sensitive scalp follicles, the following signs can indicate DHT-driven hair thinning:

• A widening centre part

• Reduced density across the top of the scalp

• Finer strands in areas that were previously fuller

• Gradual thinning without major changes to the front hairline

What Should You Do If You Notice DHT Pattern Thinning?

If you notice gradual thinning around the hairline, temples, or crown, start by tracking the change and getting the cause checked rather than assuming that DHT is responsible. Early attention can help distinguish pattern thinning from other reasons for reduced hair density.

You can keep track of your hair thinning pattern in the following ways:

• Taking clear photographs of the hairline, temples, and crown in similar lighting.

• Comparing photographs over several months instead of checking your hair every day.

• Noting whether close family members have experienced a similar pattern.

• Paying attention to sudden shedding or other changes that do not fit the usual pattern.

• Speaking with a dermatologist if the thinning continues or becomes more noticeable.

Note: DHT sensitivity is only one possible reason for hair thinning. Understanding the actual cause is more useful than assuming that testosterone or DHT is responsible.

Support Your Hair With the Right Care

Testosterone and DHT are a normal part of the body, but their effect on hair depends on how individual follicles respond to them. When follicles are sensitive to DHT, repeated exposure can gradually change the way they grow hair, leading to finer strands and reduced density over time.

Recognising these changes early can help you understand whether the pattern is linked to DHT or another cause. Rather than focusing on testosterone or DHT levels alone, looking at the overall pattern of thinning can help you take a more informed approach to your hair health.

Want to know whether your thinning follows a DHT-sensitive pattern?
Take Traya’s Hair Test for a personalised assessment and expert-guided next steps.

Frequently Asked Questions

Does high testosterone always cause pattern thinning?

Not always. Follicle sensitivity and local androgen metabolism matter more than testosterone alone.

Does high testosterone always cause baldness?

No, high testosterone does not always cause baldness. Scalp hair thinning depends more on how sensitive your hair follicles are to dihydrotestosterone (DHT) than on testosterone levels alone.

Can women have DHT-sensitive follicles?

Yes. Women produce androgens too, and genetically susceptible follicles can miniaturise even without abnormal blood results.

Can a blood test measure scalp DHT activity?

Not directly. Blood values cannot show the enzyme activity or receptor response inside each follicle.

References : 

• Trüeb RM. (2002). Molecular mechanisms of androgenetic alopecia. Experimental Gerontology, 37(8–9), 981–990. DOI: 10.1016/S0531-5565(02)00093-1
• Price VH. (2003). Androgenetic alopecia in women. Journal of Investigative Dermatology Symposium Proceedings, 8(1), 24–27. DOI: 10.1046/j.1523-1747.2003.12168.x
• Randall VA. (2008). Androgens and hair growth. Dermatologic Therapy, 21(5), 314–328. DOI: 10.1111/j.1529-8019.2008.00214.x
• Thornton MJ, Laing I, Hamada K, Messenger AG, Randall VA. (1993). Differences in testosterone metabolism by beard and scalp hair follicle dermal papilla cells. Clinical Endocrinology, 39(6), 633–639. DOI: 10.1111/j.1365-2265.1993.tb02420.x

Read More Blogs

How Irregular Sleep Patterns Disrupt Hair Growth Signals

When Sleep Goes Off-Track, Hair Growth Is One of the First Signals to BreakIf you’ve be...

Rosemary Oil with Fenugreek (Methi) Seeds for Hair Thickening

  Warm herbal oil massaged into the scalp has a way of feeling both comforting and hope...

Can You Leave Jojoba Oil in Your Hair Overnight?

Summary Yes, and for most people it's genuinely safe. It works well as a deep condition...

Folate Deficiency & Hair Loss: Complete Guide to Cellular Growth, Diagnosis & Treatment

Hair thinning that feels sudden, diffuse, and hard to explain can sometimes trace back ...

Onion Juice Hair Mask Recipes at Home

Quick Answer A simple onion hair mask starts with a fresh red onion, blended and st...