Testogel (testosterone gel) is a hormone replacement therapy prescribed for men with clinically confirmed testosterone deficiency, also known as hypogonadism. One common concern amongst patients considering or using Testogel is whether it can cause hair loss. According to MHRA-approved product information, alopecia is listed as an uncommon side effect, affecting fewer than 1 in 100 patients. The relationship between testosterone therapy and hair loss is complex, often relating to individual genetic factors and the conversion of testosterone to dihydrotestosterone (DHT), which plays a significant role in male pattern baldness in genetically susceptible individuals.

Does Testogel Cause Hair Loss?

Testogel (testosterone gel) is a hormone replacement therapy prescribed for men with clinically confirmed testosterone deficiency, also known as hypogonadism. One of the most common concerns among patients considering or using Testogel is whether it can cause hair loss.

According to the MHRA-approved product information, alopecia (hair loss) is listed as an uncommon side effect of Testogel, affecting fewer than 1 in 100 patients. The relationship between testosterone therapy and hair loss is complex and often relates to individual genetic factors.

Testosterone can be converted in the body to dihydrotestosterone (DHT), a more potent androgen that plays a significant role in male pattern baldness (androgenetic alopecia) in genetically susceptible individuals. If you have a family history of male pattern baldness, testosterone replacement therapy may accelerate a process that would have occurred naturally over time.

It is important to distinguish between different types of hair loss. Male pattern baldness, characterised by receding hairline and thinning at the crown, is influenced by genetic sensitivity to DHT. Other forms of hair loss, such as telogen effluvium (temporary shedding due to stress or illness) or alopecia areata (an autoimmune condition), are not typically caused by testosterone therapy, though any new hair loss should be properly assessed.

If you are concerned about hair loss while using Testogel, it is essential to discuss this with your GP or endocrinologist. They can help determine whether the hair loss is related to your testosterone therapy, genetic factors, or another underlying condition requiring investigation.

How Testosterone Affects Hair Growth

Understanding how testosterone influences hair growth requires knowledge of androgen metabolism and the hair growth cycle. Testosterone itself is a relatively weak androgen, but it can be converted by the enzyme 5-alpha reductase into dihydrotestosterone (DHT), which is approximately five times more potent. DHT binds to androgen receptors in hair follicles, particularly those on the scalp, and in genetically predisposed individuals, this binding can miniaturise hair follicles over time.

The hair growth cycle consists of three phases:

• Anagen (growth phase): Hair actively grows for 2–7 years

• Catagen (transition phase): A brief 2–3 week period when growth stops

• Telogen (resting phase): Hair rests for about 3 months before shedding

In androgenetic alopecia, DHT progressively shortens the anagen phase and causes follicles to shrink, producing finer, shorter hairs until eventually the follicles become dormant. This process is highly dependent on genetic sensitivity—some men have androgen receptors in scalp follicles that are particularly responsive to DHT, whilst others do not.

Interestingly, testosterone and DHT have opposite effects on different body areas. Whilst they may contribute to scalp hair loss in susceptible individuals, they promote hair growth on the face, chest, and body. This is why men with male pattern baldness often have robust facial and body hair growth. When using Testogel to restore testosterone to normal physiological levels, you are essentially replicating what your body would naturally produce, though this may unmask or accelerate genetic hair loss patterns that were previously delayed by low testosterone levels.

While alopecia is a recognised adverse reaction in the Testogel product information, many men using testosterone replacement therapy at appropriate doses will not experience significant hair loss beyond what their genetics would dictate.

Hair Loss Risk Factors with Testogel

Several factors influence whether you might experience hair loss whilst using Testogel for testosterone replacement therapy. Understanding these risk factors can help you and your healthcare provider make informed decisions about your treatment.

Genetic predisposition is the most significant risk factor. If you have a family history of male pattern baldness on either side of your family, you are more likely to experience hair thinning or loss during testosterone therapy. Androgenetic alopecia has a complex polygenic inheritance pattern, with multiple genes from both parents contributing to your risk.

Age plays an important role, as androgenetic alopecia typically becomes more apparent with advancing years. Men starting Testogel in their 40s, 50s, or beyond may notice hair changes that coincide with treatment but would likely have occurred naturally as part of the ageing process.

Dosage and testosterone levels can influence outcomes. Testogel is prescribed to restore testosterone to normal physiological ranges (according to your local laboratory's reference ranges). Supraphysiological doses—levels above the normal range—may increase DHT production and potentially accelerate hair loss in susceptible individuals. This is why regular monitoring through blood tests is essential, as recommended by the British Society for Sexual Medicine (BSSM) guidelines and the Testogel product information.

Pre-existing hair loss patterns should be considered. If you already have some degree of male pattern baldness before starting Testogel, testosterone replacement may accelerate the progression. Conversely, if you have no genetic predisposition and a full head of hair in your family, Testogel is less likely to cause significant hair loss.

Other medical conditions such as thyroid disorders, nutritional deficiencies (particularly iron), autoimmune conditions, or scalp infections can cause hair loss independently of testosterone therapy. It is crucial to exclude these conditions through appropriate investigation if hair loss occurs during treatment.

Managing Hair Changes During Testosterone Treatment

If you experience hair thinning or loss whilst using Testogel, several evidence-based strategies can help manage this concern without necessarily discontinuing your testosterone replacement therapy, which may be medically necessary for your overall health.

Medical treatments for hair loss include finasteride and minoxidil, both of which have good evidence for treating male pattern baldness. Finasteride is a 5-alpha reductase inhibitor that reduces the conversion of testosterone to DHT, thereby slowing or preventing further hair loss. However, finasteride requires careful consideration:

• It can lower PSA (prostate-specific antigen) levels by approximately 50%, affecting prostate cancer screening interpretation

• It may cause sexual side effects (erectile dysfunction, reduced libido) and mood changes in some men

• It must only be used under medical supervision and with your prescribing doctor's knowledge

Minoxidil is a topical treatment applied directly to the scalp that can stimulate hair growth. In the UK, it is available as a Pharmacy (P) medicine, meaning you should speak with a pharmacist when purchasing it. Your pharmacist can advise on proper application and potential side effects.

Optimising your testosterone dose is important. Your GP or endocrinologist should regularly monitor your testosterone levels to ensure they remain within the normal physiological range. If levels are higher than necessary, dose adjustment may help reduce DHT production whilst still treating your hypogonadism effectively.

Lifestyle factors can support overall hair health:

• Maintain a balanced diet rich in protein, iron, zinc, and B vitamins

• Manage stress through regular exercise and adequate sleep

• Avoid harsh hair treatments, excessive heat styling, or tight hairstyles

• Consider gentle, sulphate-free hair care products

Realistic expectations are essential. If you have genetic male pattern baldness, some degree of hair loss may be inevitable regardless of testosterone therapy. Testogel is restoring your testosterone to normal levels, which is important for bone health, muscle mass, mood, sexual function, and overall wellbeing. The benefits of treating clinically significant testosterone deficiency typically outweigh cosmetic concerns, though this is a personal decision to discuss with your healthcare provider.

When to Speak with Your GP About Hair Loss

Whilst some hair thinning may be expected in genetically predisposed individuals using Testogel, certain situations warrant prompt medical review to exclude other causes or complications.

You should contact your GP or prescribing specialist if you experience:

• Sudden or rapid hair loss that occurs quickly over weeks rather than gradually over months, as this may indicate telogen effluvium or another acute condition unrelated to testosterone therapy

• Patchy hair loss in circular areas, which could suggest alopecia areata, an autoimmune condition requiring different management

• Hair loss accompanied by scalp symptoms such as redness, scaling, itching, or pain, which may indicate a dermatological condition like seborrhoeic dermatitis or scalp infection

• Signs of scarring alopecia including permanent hair loss with scalp scarring, pustules, or inflammation, which requires urgent dermatology referral

• Hair loss with other new symptoms including fatigue, weight changes, or mood disturbances, which could suggest thyroid dysfunction or other hormonal imbalances requiring investigation

• Concerns about your testosterone levels or side effects from Testogel, as dose adjustment may be appropriate

Your GP can arrange appropriate investigations tailored to your specific symptoms and clinical findings. These may include blood tests to check your testosterone levels, full blood count, thyroid function, ferritin (iron stores), and other tests as indicated. According to the British Society for Sexual Medicine guidance and the Testogel product information, patients should have testosterone levels monitored at 3-6 months after starting treatment, then periodically thereafter based on clinical need.

If hair loss is significantly affecting your quality of life or self-esteem, this is a valid reason to seek medical advice. Your doctor can discuss whether referral to a dermatologist is appropriate, review whether the benefits of testosterone replacement outweigh the cosmetic concerns in your individual case, and explore treatment options for hair loss that are compatible with your testosterone therapy.

Remember that testosterone replacement therapy is prescribed for clinically significant hypogonadism with symptoms and biochemical confirmation. Discontinuing medically necessary treatment solely due to hair loss concerns may lead to return of hypogonadism symptoms and potential long-term health consequences. A balanced discussion with your healthcare provider will help you make the best decision for your overall health and wellbeing.

If you suspect Testogel has caused hair loss or any other side effect, you can report this through the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

Frequently Asked Questions