Some men notice increased shedding or a receding hairline after starting testosterone replacement therapy (TRT), which can raise concerns about whether treatment is contributing to hair loss.

The relationship isn’t straightforward. TRT may influence hair loss in men who are genetically predisposed to male pattern baldness, but it doesn’t affect everyone in the same way.

This article explains what’s known about TRT and hair loss, where the evidence is still uncertain, and what to do if you notice thinning during treatment.

• Does TRT cause hair loss?
• What is DHT, and why does it affect scalp hair?
• What does the research on TRT and hair loss show?
• TRT may accelerate hair loss rather than start it
• Not all hair loss on TRT is caused by DHT
• Pattern loss and diffuse shedding can happen together
• Does your TRT dose affect hair loss?
• Do injections cause more hair loss than gels or creams?
• Can you predict hair loss before starting TRT?
• Can you prevent hair loss while taking TRT?
• Will hair grow back if you stop TRT?
• TRT and body hair aren’t the same as scalp hair
• What should you do if you notice hair loss on TRT?

Does TRT cause hair loss?

TRT can potentially speed up androgenetic alopecia, better known as male pattern baldness, in men who are genetically predisposed to it. However, TRT doesn’t usually create a new hair-loss condition out of nowhere. 

A recent systematic review found a potential link between androgen treatment and hair loss, but there was very little direct evidence from men receiving medically prescribed TRT for testosterone deficiency [1].

Male pattern hair loss can be caused by:

• Genetic susceptibility
• Age
• Androgen activity within the scalp
• The sensitivity of individual hair follicles to dihydrotestosterone (DHT)
• Local enzyme and androgen receptor activity

Two men can have similar testosterone and DHT levels but very different hairlines. One may retain a full head of hair into later life, while the other begins thinning in his twenties.

What is DHT, and why does it affect scalp hair?

Dihydrotestosterone is a potent androgen that’s made when the enzyme 5-alpha-reductase converts testosterone into DHT. DHT has useful roles in male development and sexual physiology, and in androgen-sensitive areas of the scalp, DHT binds to androgen receptors and gradually alters the normal hair cycle. 

Over time:

• The active growth phase becomes shorter
• New hairs grow for less time
• Hair shafts become finer and shorter
• Soft, barely visible hairs gradually replace terminal hairs
• Some follicles eventually stop producing noticeable hair

This process is known as follicular miniaturisation, and it usually affects the temples, frontal hairline, and crown, while sparing the sides and back of the scalp [2].

TRT can increase the testosterone available for DHT conversion, but how sensitive your follicles are depends on your genetics.

What does the research on TRT and hair loss show?

A 2026 review examined 14 studies involving 2,344 people using testosterone or other androgens. Overall, the results suggested that androgen treatment can increase the risk of hair loss in some groups. However, the studies varied considerably in their populations, treatments, doses, and methods of measuring hair loss [1].

Crucially, the review found that hair-loss outcomes weren’t available for androgen-deficient men receiving conventional testosterone treatment. 

Much of the evidence came from:

• Transgender men receiving gender-affirming testosterone
• People using anabolic-androgenic steroids
• Women receiving testosterone
• Older experimental studies using topical testosterone on existing alopecia

These groups can provide useful clues, but they don’t directly answer what happens to men receiving carefully monitored TRT for hypogonadism.

What happened in the studies?

Among transgender men receiving androgen therapy, the proportion with androgenetic alopecia rose from 1.9% before treatment to 19.5% after treatment. However, the average follow-up was several years, and hair loss would also be expected to become more common with age.

Among men using anabolic-androgenic steroids, reported alopecia increased from 2% to 12%. These findings shouldn’t be treated as evidence about medical TRT because anabolic steroid use often involves supraphysiological doses, multiple compounds, and testosterone levels well beyond the normal range.

In older trials of topical testosterone involving men with existing male pattern baldness:

• 16.3% reported worsening hair loss
• 17.3% reported improvement
• 66.3% reported no change

The mixed findings show why it’s difficult to claim that testosterone has one predictable effect on everyone’s hair.

TRT may accelerate hair loss rather than start it

Restoring your testosterone from a deficient level to a healthy physiological range might make hair loss noticeable sooner.

That doesn’t necessarily mean the TRT dose is excessive or that treatment has been poorly managed. It means the follicles are responding to increased androgen exposure.

Clues that you may be developing male pattern baldness include:

• Gradual recession at the temples
• A more pronounced M-shaped hairline
• Thinning at the crown
• Finer, shorter hairs around the hairline
• Slow progression rather than sudden shedding

It’s also possible that hair loss was already underway before TRT but became more noticeable after you started paying closer attention.

Not all hair loss on TRT is caused by DHT

Hair loss can happen for many reasons, including:

• Recent illness or fever
• Psychological stress
• Rapid weight loss
• Iron deficiency
• Thyroid disease
• Nutritional deficiencies
• New medicines
• Scalp inflammation or infection
• Alopecia areata
• Significant changes to diet or training

Temporary diffuse shedding is often caused by telogen effluvium. Rather than following the familiar receding-hairline pattern, telogen effluvium tends to cause increased shedding across the whole scalp. It can begin several months after illness, emotional stress, surgery, rapid weight loss, or another physical shock.

Pattern loss and diffuse shedding can happen together

It’s possible to have both androgenetic alopecia and telogen effluvium.

For example, rapid weight loss or illness may trigger widespread shedding, making previously subtle male pattern hair loss much more visible. Once the temporary shedding settles, the underlying recession or crown thinning may remain.

A GP or dermatologist can often distinguish between these conditions by examining the pattern, scalp, and hair shafts. Dermoscopy or additional investigations may occasionally be needed.

Does your TRT dose affect hair loss?

Higher testosterone exposure generally creates more opportunity for conversion into DHT. Keeping treatment within a healthy physiological range is therefore sensible, both for hair and for your wider health.

TRT treatment should be monitored and adjusted according to your symptoms, blood results, preparation, and individual response.

Persistently excessive testosterone can also increase the likelihood of other unwanted effects, including acne, oily skin, and raised haematocrit. 

You can read more in our guide to the side effects and risks of TRT.

Do injections cause more hair loss than gels or creams?

There isn’t good evidence showing that one standard TRT preparation consistently causes more hair loss than another.

Injections, gels, creams, and oral testosterone produce different hormone patterns, and some preparations may cause higher peaks or different DHT exposure. But your genetics and follicle sensitivity are likely to matter more than the route of treatment alone.

Changing preparation purely because of hair loss shouldn’t be done without reviewing:

• Your testosterone level
• The timing of your blood test
• Your TRT dose and frequency
• Whether the hair loss is actually androgenetic
• Your other symptoms and treatment goals

Our guide toTRT injections, gels, creams, and capsules explains how the main options differ.

Can you predict hair loss before starting TRT?

Serum DHT levels aren’t a simple baldness score. What’s happening within the follicle, including local DHT production and androgen receptor sensitivity, may be more relevant than the amount measured in your blood.

Your risk may be higher if:

• Your hairline was already receding before TRT
• You have thinning at the crown
• Male pattern baldness runs in your family
• You began losing hair at a relatively young age
• Your hair follicles show early miniaturisation on examination

Family history is useful, but it isn’t always obvious. Hair-loss susceptibility is inherited through multiple genes and can come from either side of the family.

Can you prevent hair loss while taking TRT?

You can’t change your genetic susceptibility, but established treatments may slow male pattern hair loss and, in some men, improve density.

The two principal treatments for male pattern baldness are minoxidil and finasteride. Neither works for everyone, and their benefits generally last only while treatment continues.

Minoxidil

Minoxidil promotes hair growth without directly lowering testosterone or DHT and is available as an over-the-counter topical cream. 

It’s applied to the scalp and can help prolong the growth phase of the hair cycle. Some men experience increased shedding shortly after starting, which can happen as hairs move into a new growth cycle.

It usually needs to be used consistently for several months before you can judge whether it’s helping. Any benefit is gradually lost after treatment is stopped.

Speak to a pharmacist, GP, or dermatologist about whether it’s appropriate for you.

Finasteride

Finasteride is a 5-alpha-reductase inhibitor. It reduces the conversion of testosterone into DHT, potentially slowing hair loss and improving growth in some men. It’s licensed at a 1 mg dose for male pattern hair loss.

However, combining finasteride and TRT needs to be discussed with your doctor because DHT and finasteride can cause side effects, including depression and sexual dysfunction.

Finasteride can also affect PSA results, so make sure the clinician responsible for your TRT and prostate monitoring knows you’re taking it.

Will hair grow back if you stop TRT?

If TRT has triggered temporary shedding for another reason, hair may recover once the trigger is corrected. If it has accelerated androgenetic alopecia, reducing androgen exposure might slow progression, but miniaturised follicles may not fully recover without specific treatment.

Stopping TRT also means testosterone levels are likely to fall again, and the original symptoms of deficiency may return.

That’s why hair loss should be managed as part of the wider treatment picture, not by stopping testosterone without clinical advice.

TRT and body hair aren’t the same as scalp hair

One of the aspects of androgen biology is that the same hormone can produce opposite effects in different locations.

Higher androgen activity may encourage:

• Beard growth
• Chest and body hair
• Thicker facial hair

At the same time, DHT can shrink genetically susceptible follicles on the scalp.

So, it’s entirely possible to notice more body hair while your temples begin to thin. The response depends on where the follicle is and how it reacts to androgen signalling.

What should you do if you notice hair loss on TRT?

Hair loss is rarely an emergency, which gives you time to establish what’s actually happening and consider your options properly.

Take clear photographs

Photographs are much more reliable than checking your hairline in a different mirror every morning.

Try to use:

• The same room and lighting
• The same camera angle
• Dry hair without styling products
• Front, temple, crown, and overhead views
• Monthly rather than daily comparisons

Hair grows slowly, so daily checking usually creates anxiety without giving you useful information.

Speak to your TRT doctor

Your doctor can review whether your testosterone exposure is appropriate and whether any treatment changes are justified.

This may include looking at:

• Your current TRT dose
• Total and free testosterone
• When the blood sample was taken
• Changes in other androgen-related symptoms
• Whether levels are above the intended range
• Any recent changes to your treatment

Don’t reduce your dose or change your injection frequency based on hair loss alone. An unnecessary change may bring back the symptoms TRT was prescribed to treat without addressing the real cause of the shedding.

Read more about target testosterone levels on TRT.

Not sure where to begin? Use Leger Clinic’s Get Started tool to explore your next steps.

References