Testogel is a topical testosterone replacement therapy prescribed for men with confirmed testosterone deficiency. Knowing where to put Testogel correctly is essential for effective treatment and preventing accidental transfer to others. The approved application sites vary by formulation: the 16.2 mg/g pump should be applied to the shoulders and/or upper arms only, whilst the 50 mg/5 g sachets can be applied to the shoulders, upper arms, or abdomen. Proper technique ensures optimal hormone absorption, maintains stable testosterone levels, and minimises safety risks. This guide explains the correct application sites, step-by-step instructions, and crucial precautions to help you use Testogel safely and effectively.

What Is Testogel and How Does It Work?

Testogel is a topical testosterone replacement therapy (TRT) prescribed for adult men with confirmed testosterone deficiency, also known as hypogonadism. It contains testosterone as the active ingredient, delivered in a clear gel formulation that is applied directly to the skin. In the UK, Testogel is available in two main formulations:

• Testogel 50 mg/5 g sachets (1% gel) – each sachet contains 50 mg of testosterone, with a typical starting daily dose of 50 mg

• Testogel 16.2 mg/g pump – each pump actuation delivers 20.25 mg of testosterone, with a typical starting daily dose of 40.5 mg (two actuations)

The gel works through transdermal absorption, meaning testosterone passes through the skin and enters the bloodstream gradually over several hours. Once absorbed, testosterone circulates in the body and binds to androgen receptors in various tissues, helping to restore normal physiological levels. This mechanism supports multiple bodily functions including muscle mass maintenance, bone density, libido, mood regulation, and energy levels.

Testosterone replacement is indicated when blood tests confirm low testosterone levels accompanied by symptoms such as reduced sexual desire, fatigue, loss of muscle mass, or mood disturbances. According to NICE Clinical Knowledge Summaries (CKS), diagnosis should be based on at least two early-morning serum testosterone measurements showing levels below the normal range, alongside relevant clinical symptoms. Testogel is licensed for use in adult men with confirmed hypogonadism only; it is not licensed for use in women or children, and should never be used for performance enhancement.

The transdermal route offers several advantages over other forms of testosterone replacement, including steady hormone levels throughout the day, avoidance of first-pass liver metabolism, and ease of dose adjustment. However, proper application technique is essential to ensure optimal absorption and to minimise the risk of transferring testosterone to others through skin-to-skin contact. Patients should always follow their prescriber's instructions and attend regular monitoring appointments to assess treatment response and check for potential adverse effects.

Where to Apply Testogel: Recommended Application Sites

Correct application site selection is crucial for optimal testosterone absorption and treatment efficacy. The approved application sites differ between Testogel formulations, so it is essential to follow the instructions specific to your product.

For Testogel 16.2 mg/g pump:

According to the UK Summary of Product Characteristics (SmPC), apply the gel to clean, dry, intact skin on the shoulders and/or upper arms only. The abdomen is not an approved site for this formulation.

For Testogel 50 mg/5 g sachets (1% gel):

Apply to clean, dry, intact skin on the shoulders, upper arms, or abdomen.

These sites have been selected based on clinical studies demonstrating reliable testosterone absorption and practical considerations regarding daily activities and clothing coverage. The skin in these areas typically has appropriate thickness and blood supply to facilitate steady hormone uptake.

Application site rotation is advisable to prevent skin irritation. Patients using Testogel daily should alternate between the approved sites rather than applying to exactly the same spot each day. For example, one might apply to the right shoulder one day, the left shoulder the next, creating a rotation pattern that allows each area time to recover.

The gel should be spread thinly and evenly over the application site as directed in the product information leaflet. After application, allow the gel to dry completely for 3–5 minutes before dressing. This drying time is essential to prevent the gel from rubbing off onto clothing or being transferred to others through direct contact.

Patients should apply Testogel at approximately the same time each day, preferably in the morning, to help maintain stable hormone levels. Consistency in application timing and site selection optimises treatment outcomes. Always follow your prescriber's instructions regarding dose and application routine.

Step-by-Step Guide to Applying Testogel Safely

Proper application technique ensures maximum therapeutic benefit whilst minimising safety risks. Follow this systematic approach for safe and effective Testogel use:

Before application:

1. Wash and dry your hands thoroughly – This prevents contamination and prepares for safe handling

2. Ensure the application site is clean and completely dry – Shower or bathe before application if needed, then dry the skin thoroughly. Avoid applying to damp skin as this reduces absorption

3. Check skin integrity – Do not apply to broken, irritated, or damaged skin. Inspect for cuts, rashes, or inflammation

During application:

1. Open the sachet or prepare the pump – If using sachets, tear open carefully. For pump dispensers, prime according to the instructions before first use

2. Squeeze the gel onto your palm or fingers – Use the prescribed dose as directed by your doctor

3. Apply to the approved site for your formulation – For the 16.2 mg/g pump, apply to the shoulders and/or upper arms only. For the 50 mg/5 g sachets, apply to the shoulders, upper arms, or abdomen. Spread the gel thinly and evenly over the application area as directed in the product leaflet

4. Rub in gently – Use smooth, even strokes until the gel appears evenly distributed. Do not massage vigorously

5. Allow to dry completely – Wait 3–5 minutes before dressing. The gel should feel dry to touch. Important: The gel is flammable until dry; keep away from naked flames and do not smoke during and immediately after application

After application:

1. Wash your hands immediately and thoroughly with soap and water – This critical step prevents accidental transfer to others

2. Cover the application site with clothing – Wear a shirt or top that covers the treated area

3. Avoid washing the application site for the recommended time – For the 16.2 mg/g pump, wait at least 2 hours before showering or swimming. For the 50 mg/5 g sachets, wait at least 6 hours. Washing sooner may reduce testosterone absorption

4. If close skin-to-skin contact is anticipated and the application site cannot be kept covered by clothing, wash the application area with soap and water beforehand to prevent transfer

Important safety considerations: Never apply Testogel to the genital area. Avoid skin-to-skin contact with others, particularly women and children, until you have showered or bathed. If direct contact occurs accidentally, the other person should wash the affected area immediately with soap and water.

Areas to Avoid When Using Testogel

Understanding where not to apply Testogel is as important as knowing the correct application sites. Certain body areas pose risks of inadequate absorption, increased adverse effects, or safety concerns.

Never apply Testogel to:

• Genital area (penis or scrotum) – This is explicitly contraindicated due to the risk of excessive local absorption, potential skin irritation, and disproportionate conversion to dihydrotestosterone (DHT). Application to genital skin may cause adverse local effects and does not provide the controlled systemic absorption required for testosterone replacement therapy

• Broken, damaged, or irritated skin – Cuts, grazes, eczema, psoriasis, or any compromised skin barrier can lead to unpredictable absorption rates and increased risk of local irritation or systemic side effects

• Oily or recently moisturised skin – Lotions, creams, or oils create a barrier that significantly impairs testosterone absorption. Always apply to clean, product-free skin

• Abdomen (if using Testogel 16.2 mg/g pump) – The abdomen is not an approved application site for this formulation. Apply only to the shoulders and/or upper arms

Other areas to avoid:

Apply Testogel only to the sites approved in the UK Summary of Product Characteristics for your specific formulation. Do not apply to the face, head, chest, back, or lower body (legs, feet, buttocks), as these sites have not been adequately studied for Testogel application and may provide inconsistent absorption or pose practical difficulties.

Do not cover the application site with occlusive dressings (bandages or airtight coverings) whilst the gel is wet, as this may alter absorption.

If you have extensive skin conditions affecting the recommended application sites, contact your GP or prescribing clinician before continuing treatment. They may need to assess alternative sites or consider different testosterone replacement formulations. Never improvise application sites without medical guidance, as this may compromise treatment efficacy and safety. Patients with questions about appropriate application areas should seek clarification from their healthcare provider or pharmacist rather than making assumptions that could affect treatment outcomes.

Common Mistakes and How to Prevent Gel Transfer

Preventing testosterone transfer to others is a critical safety consideration with Testogel use. Unintended exposure can cause virilisation in women (development of male characteristics such as acne, increased body hair, voice changes) and premature sexual development in children (enlarged genitals, early pubic hair, increased erections or libido, aggressive behaviour). Understanding common errors helps patients use Testogel safely and effectively.

Common application mistakes include:

• Insufficient drying time – Dressing immediately after application leaves wet gel that transfers to clothing and increases contact transfer risk. Always wait 3–5 minutes until completely dry

• Inadequate handwashing – Failing to wash hands thoroughly after application is the most frequent cause of accidental transfer. Use soap and water, washing for at least 20 seconds

• Applying to the wrong site – For the 16.2 mg/g pump, applying to the abdomen (not an approved site) may reduce efficacy. Always check your product's approved sites

• Showering or swimming too soon – For the 16.2 mg/g pump, washing within 2 hours of application significantly reduces testosterone absorption. For the 50 mg/5 g sachets, avoid washing within 6 hours. Plan application timing around daily activities

• Forgetting to cover application sites – Exposed treated skin increases transfer risk during casual contact

Strategies to prevent gel transfer:

For household members and partners:

• Avoid direct skin-to-skin contact with application sites until you have showered (wait at least 2 hours for the pump or 6 hours for sachets after application)

• If close contact is anticipated and the application site cannot be kept covered by clothing, wash the application area with soap and water first

• If unexpected contact occurs, the other person should wash the contact area immediately with soap and water

• Sleep in clothing that covers application sites, or ensure sufficient time has passed since application

For children specifically:

• Be especially vigilant as children are more vulnerable to testosterone effects

• Avoid cuddling or close physical contact until application sites are covered and dry

• Keep Testogel stored safely out of children's reach

• Watch for signs of unintended exposure in household members. In women, these may include acne, increased body hair, or voice changes. In children, watch for signs of early puberty such as enlarged genitals, early pubic hair, increased erections or libido, or aggressive behaviour

If you suspect someone has been exposed to Testogel, they should wash the affected area immediately with soap and water and contact their GP if any concerning symptoms develop. For persistent concerns about transfer risk or if household circumstances make safe use challenging, discuss alternative testosterone formulations with your prescribing clinician. Injectable or oral testosterone preparations may be more appropriate in some situations where transfer risk cannot be adequately managed.

Reporting side effects: If you or anyone in your household experiences side effects from Testogel, you can report them via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or by searching for MHRA Yellow Card in the Google Play or Apple App Store.

Frequently Asked Questions