Many men using Testogel for testosterone replacement therapy wonder whether it is safe to sunbathe whilst on treatment. Testogel is a transdermal gel licensed in the UK for male hypogonadism, applied daily to the skin where testosterone is gradually absorbed. Whilst there is no official contraindication to sun exposure, several practical considerations affect both medication efficacy and safety. Understanding application timing, transfer risks, and skin protection helps patients enjoy outdoor activities confidently whilst maintaining effective treatment. This article examines the evidence and provides practical guidance aligned with MHRA-approved product information and NHS sun safety recommendations.

What Is Testogel and How Does It Work?

Testogel is a transdermal testosterone replacement therapy (TRT) licensed in the UK for treating male hypogonadism—a condition characterised by abnormally low testosterone levels. The gel contains testosterone as the active pharmaceutical ingredient and is available in two formulations: Testogel 50 mg/5 g (1%) sachets and Testogel 16.2 mg/g pump (delivering approximately 20.25 mg testosterone per pump actuation). It is manufactured by Besins Healthcare and regulated by the Medicines and Healthcare products Regulatory Agency (MHRA).

The mechanism of action involves percutaneous absorption of testosterone through intact skin. Once applied to clean, dry skin—usually on the shoulders, upper arms, or abdomen (for the 1% formulation; shoulders and upper arms only for the 16.2 mg/g pump)—the gel dries within minutes, forming a reservoir in the stratum corneum. Testosterone is then gradually released into the systemic circulation over 24 hours, bypassing hepatic first-pass metabolism and providing relatively stable serum testosterone concentrations.

Testosterone exerts its effects by binding to androgen receptors in target tissues, influencing protein synthesis, bone density, muscle mass, libido, mood, and secondary sexual characteristics. Common adverse effects include application site reactions (erythema, pruritus), acne, and mood changes. Serious risks include polycythaemia (particularly if haematocrit exceeds 0.54), and potential effects on prostate parameters. Cardiovascular risk evidence is mixed; patients should have cardiovascular risk factors monitored. Inadvertent transfer to others through skin-to-skin contact is a significant safety concern.

Testogel is contraindicated in known or suspected prostate cancer, male breast cancer, and severe cardiac, hepatic or renal insufficiency. It also suppresses spermatogenesis and is not suitable for men trying to conceive.

Patients using Testogel require regular monitoring including serum testosterone levels, full blood count (haemoglobin/haematocrit), prostate-specific antigen (PSA), digital rectal examination as appropriate, and cardiovascular risk assessment. The gel must be used consistently and correctly to maintain stable testosterone concentrations and optimise therapeutic outcomes whilst minimising safety concerns.

Report suspected side effects via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

Can You Sunbathe While Using Testogel?

There is no official contraindication to sunbathing whilst using Testogel, and the MHRA-approved Summary of Product Characteristics (SmPC) does not specifically prohibit sun exposure. However, several practical considerations warrant careful attention to ensure both medication efficacy and skin safety.

The primary concern relates to the application site and absorption dynamics. Testogel requires approximately 3–5 minutes to dry on the skin surface, after which the testosterone begins its gradual absorption process over several hours. The SmPC for Testogel does not identify photosensitivity as a recognised adverse reaction, suggesting testosterone itself does not increase skin sensitivity to ultraviolet radiation.

That said, practical guidance suggests allowing adequate time between application and sun exposure. The SmPC advises avoiding washing or swimming for at least 6 hours after applying Testogel 1% (or as specified on the label for the 16.2 mg/g formulation). This timeframe ensures optimal absorption and reduces the risk of the gel being affected by perspiration, which may occur during sun exposure.

Additionally, patients should consider that covering the application site with clothing provides dual benefits: it prevents accidental transfer of testosterone to others (a significant safety concern, particularly with children and women) and offers sun protection. The NHS advises that all individuals, regardless of medication use, should practise safe sun exposure habits, including using broad-spectrum sunscreen with SPF 30 or higher, seeking shade during peak UV hours (11 am–3 pm), and wearing protective clothing.

Important safety considerations include:

• Testogel contains alcohol and is flammable until dry; avoid smoking or naked flames until completely dry

• Do not apply sunscreen or other topical products to the application site until after the SmPC-recommended interval for washing/swimming

• If close skin contact with others is anticipated, wash the application site thoroughly beforehand

Sun Exposure Risks and Precautions with Testogel

Whilst Testogel itself does not cause photosensitivity, several indirect risks merit consideration when combining testosterone therapy with sun exposure. Understanding these factors helps patients make informed decisions about outdoor activities.

Skin integrity and application site reactions represent the first consideration. Testogel can cause local skin irritation, dryness, or erythema in some users. Sunburn or excessive UV exposure on already irritated skin may exacerbate discomfort and potentially impair the skin barrier function, affecting testosterone absorption. Patients experiencing application site reactions should rotate application areas as recommended and avoid applying gel to sunburnt or damaged skin.

Perspiration and physical activity during sun exposure pose practical challenges. Heavy sweating before the gel is fully absorbed may affect treatment efficacy. The SmPC advises avoiding washing or swimming for at least 6 hours after applying Testogel 1% (or as specified for the 16.2 mg/g formulation); similar caution applies to activities causing significant perspiration. Allow the gel to dry fully before engaging in activities that might cause heavy sweating.

Transfer risk to others increases in social sunbathing contexts. Testosterone transfer through direct skin contact represents a serious safety concern, particularly for pregnant women, children, and female partners. Beach or poolside environments where physical contact is common require extra vigilance. Patients should ensure the application site is covered with clothing once the gel has dried, and wash the application site thoroughly before anticipated close skin contact. If accidental contact occurs, the other person should wash the area with soap and water as soon as possible.

General sun safety remains paramount. Testosterone therapy does not provide any photoprotection, and patients should follow standard NHS sun safety advice: apply broad-spectrum sunscreen (SPF 30+) to all exposed skin (except the Testogel application site until after the recommended interval), reapply every 2 hours and after swimming, wear UV-protective clothing, and monitor for signs of sunburn. Patients should seek medical advice for any new or changing skin lesions.

Remember that Testogel contains alcohol and is flammable until dry; avoid smoking or naked flames during application and until the gel has completely dried.

How to Apply Testogel Safely Before Sun Exposure

Optimising Testogel application technique when planning sun exposure requires strategic timing and practical adjustments to maintain treatment efficacy whilst enjoying outdoor activities safely.

Timing your application represents the most critical factor. Testogel 1% is typically applied once daily, preferably in the morning, as recommended in the SmPC. If planning sun exposure, apply the gel at least 6 hours before swimming or washing the application site (or as specified on the label for the 16.2 mg/g formulation). Any changes to your dosing schedule should be discussed with your prescriber.

Application site selection should account for sun exposure plans. For Testogel 1%, licensed application sites include the shoulders, upper arms, or abdomen. For Testogel 16.2 mg/g pump, only the shoulders and upper arms are licensed application sites. If wearing sleeveless clothing or swimwear, consider applying to the abdomen (for the 1% formulation only) or areas that will remain covered. Never apply Testogel to the genital area, broken skin, or areas with dermatological conditions.

Step-by-step safe application protocol:

• Wash and thoroughly dry hands and the application site

• Open the sachet or prepare the pump dispenser

• Apply the gel in a thin, even layer to the designated area

• Allow to dry completely (3–5 minutes) without dressing

• Wash hands thoroughly with soap and water immediately after application

• Cover the application site with clothing before any social contact

• Avoid washing or swimming for at least 6 hours (Testogel 1%) or as specified on the product label

• Do not apply sunscreen directly to the application site until after the recommended interval

• Avoid naked flames or smoking until the gel has completely dried (flammable)

Additional precautions include using separate towels if sharing facilities, avoiding situations where others might touch the application site, and washing the application site thoroughly before anticipated close skin contact. If contact occurs, the other person should wash the area with soap and water immediately.

If you experience unusual skin reactions, persistent irritation at application sites, or have concerns about combining Testogel with sun exposure, contact your GP or prescribing endocrinologist for personalised advice. Patients should never adjust their dosing schedule without medical consultation, as maintaining consistent testosterone levels is essential for treatment efficacy.

Report any suspected side effects via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk or the Yellow Card app).

Frequently Asked Questions