How long should I take Testogel for? The duration of Testogel treatment depends on the underlying cause of your low testosterone. For most men with primary or secondary hypogonadism, testosterone replacement therapy is typically lifelong, as the body's inability to produce adequate testosterone is usually permanent. However, if your low testosterone results from reversible factors such as obesity, certain medications, or chronic illness, treatment may be temporary—often 3–6 months whilst addressing the underlying cause. There is no standard fixed duration; your doctor will establish an individualised treatment plan based on your diagnosis, symptom response, and overall health, with regular reviews to determine whether ongoing treatment remains appropriate.

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 where the testes produce insufficient testosterone. It contains testosterone as the active ingredient and is available in two formulations: 50 mg/5 g (1%) sachets and 16.2 mg/g metered-dose pump. The gel is applied once daily to clean, dry, intact skin—for the 1% sachets, application sites include shoulders, upper arms, or abdomen, while the 16.2 mg/g pump should only be applied to shoulders or upper arms.

Once applied, testosterone is absorbed through the skin into the bloodstream, bypassing first-pass hepatic metabolism. This transdermal route provides relatively stable hormone levels with fewer peaks than injectable formulations. Peak serum concentrations are typically reached within 2–4 hours of application, with steady-state levels achieved after several days of consistent use.

The mechanism of action involves testosterone binding to androgen receptors in target tissues throughout the body. This triggers protein synthesis, supports muscle mass maintenance, influences bone density, affects mood and cognitive function, and maintains libido and sexual function. Testosterone also plays roles in red blood cell production and fat distribution.

Testogel is prescribed when blood tests confirm low testosterone levels (typically below 12 nmol/L on two separate early morning samples) accompanied by clinical symptoms such as reduced libido, erectile dysfunction, fatigue, decreased muscle mass, mood changes, or reduced bone density. For borderline values (8–12 nmol/L), additional tests including LH, FSH, SHBG and calculated free testosterone may be considered. The MHRA-approved product is available only on prescription following proper clinical assessment and diagnosis by a qualified healthcare professional.

Important safety advice: After application, wash hands thoroughly, allow the gel to dry completely, and cover the application site with clothing. Avoid skin-to-skin contact with others, particularly women and children, until the site is washed or covered. Avoid bathing or swimming for the period advised in the product information. The gel is flammable until dry, so avoid naked flames or smoking during application. Never apply to genitals or broken skin.

How Long Should I Take Testogel For?

The duration of Testogel treatment depends fundamentally on the underlying cause of your low testosterone. For most men with primary or secondary hypogonadism, testosterone replacement therapy is a lifelong treatment because the body's inability to produce adequate testosterone is typically permanent. The testes or hypothalamic-pituitary axis do not spontaneously recover function in most cases of established hypogonadism.

If your low testosterone results from a reversible cause—such as obesity, certain medications (opioids, corticosteroids), excessive alcohol consumption, or poorly controlled chronic illness—your doctor may recommend a trial period of 3–6 months whilst addressing the underlying factor. In these situations, testosterone therapy might be temporary, with reassessment after lifestyle modifications or treatment of the primary condition.

For men with age-related testosterone decline (sometimes called late-onset hypogonadism), the picture is more nuanced. NICE Clinical Knowledge Summary guidance emphasises that diagnosis requires both symptoms and confirmed low testosterone levels—age alone is not an indication for treatment. Treatment decisions should be individualised, balancing symptom improvement against potential risks. Some men may use TRT for many years, whilst others might trial it for 6–12 months to assess benefit.

There is no standard fixed duration that applies to all patients. Your endocrinologist or GP will establish a treatment plan based on your specific diagnosis, symptom response, blood test results, and overall health status. If there is no meaningful symptomatic improvement after 6–12 months despite normalised testosterone levels, treatment may be discontinued. Regular reviews—typically every 3–6 months initially, then annually once stable—are essential to determine whether ongoing treatment remains appropriate and beneficial.

Complex cases, particularly those involving secondary hypogonadism or where fertility is a priority, may require referral to specialist endocrinology services. The decision to continue Testogel should always be a collaborative one between you and your healthcare team, reassessed periodically throughout your treatment journey.

Monitoring Your Treatment: Blood Tests and Reviews

Regular monitoring is essential for safe and effective Testogel use. UK guidelines from NICE Clinical Knowledge Summary and the British Society for Sexual Medicine recommend structured follow-up to assess treatment response, adjust dosing, and identify potential adverse effects early.

Initially, you should have a baseline assessment before starting treatment, including:

• Testosterone levels (two early morning samples)

• LH and FSH (to distinguish primary from secondary hypogonadism)

• SHBG (particularly if testosterone is borderline)

• Full blood count (haemoglobin and haematocrit)

• Prostate-specific antigen (PSA) and digital rectal examination (if age-appropriate)

• Liver function tests

• Lipid profile

• Blood pressure and BMI

Follow-up blood tests are typically scheduled at 3 months, 6 months, and then annually if stable. These monitor testosterone levels to ensure they're within the normal physiological range (typically 12–30 nmol/L), though target ranges may vary between laboratories. Timing of blood samples is product-specific—for 1% sachets, samples should be taken before the morning dose; for the 16.2 mg/g pump, sampling 2–4 hours post-application may be advised. Your doctor will check that levels aren't too high, which could increase side effect risks, or too low, suggesting inadequate dosing or absorption.

Haematocrit monitoring is particularly important because testosterone stimulates red blood cell production. Elevated haematocrit (≥0.54) increases blood viscosity and thrombotic risk, potentially requiring dose reduction, temporary treatment cessation, or occasionally venesection. Men with pre-existing polycythaemia, sleep apnoea, or cardiovascular disease require especially careful monitoring.

PSA levels should be checked at baseline, 3 and 12 months, then annually. Referral to urology is recommended for abnormal digital rectal examination findings or age-specific PSA above threshold (as per NICE NG12 guidance), or if PSA rises rapidly (e.g., >1.4 ng/mL/year). Additionally, your clinician will assess symptom improvement, side effects, skin reactions at application sites, blood pressure, weight changes, and overall treatment satisfaction at each review.

Can You Stop Taking Testogel Safely?

Stopping Testogel requires careful consideration and should always be discussed with your prescribing doctor rather than undertaken independently. Unlike some medications, there is no physical withdrawal syndrome or dangerous rebound effect from ceasing testosterone replacement therapy, but the underlying symptoms of hypogonadism will typically return.

If you stop Testogel, your testosterone levels will decline to pre-treatment values within days to weeks, as the exogenous hormone is metabolised and cleared from your system. The half-life of transdermal testosterone is relatively short, meaning levels drop fairly rapidly once application ceases. Consequently, symptoms such as fatigue, low mood, reduced libido, and decreased energy will likely re-emerge as your testosterone returns to hypogonadal levels.

Reasons for stopping might include:

• Inadequate symptom improvement despite optimised dosing

• Troublesome side effects (skin irritation, acne, mood changes)

• Development of contraindications (prostate cancer diagnosis, severe polycythaemia)

• Resolution of reversible causes of low testosterone

• Patient preference or lifestyle factors

• Fertility concerns (testosterone suppresses sperm production)

If you're considering stopping because of side effects, discuss this with your doctor first—often, dose adjustment, application site rotation, or switching to alternative TRT formulations (injections, patches) can resolve issues without abandoning treatment entirely.

For men wishing to preserve or restore fertility, stopping Testogel is necessary, as exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis, reducing sperm production. Recovery of spermatogenesis is variable, often taking 3–12+ months after cessation, and may require specialist andrology input. Fertility-preserving treatments such as hCG or SERMs require specialist referral to fertility/urology services and are often used off-label in the UK.

Arrange appropriate follow-up after stopping, including a morning testosterone test at 6–8 weeks, to monitor symptom recurrence and discuss alternative management strategies if required. Seek urgent medical attention if you develop acute chest pain, breathlessness, unilateral leg swelling, or neurological symptoms after stopping treatment.

Long-Term Use: Benefits and Considerations

Long-term Testogel use, when appropriately monitored, can provide sustained benefits for men with confirmed hypogonadism. Clinical studies demonstrate that continued testosterone replacement therapy maintains improvements in sexual function, mood, energy levels, and quality of life. Many men report sustained enhancement in libido, erectile function, and overall wellbeing when testosterone levels are maintained within the physiological range.

Physical benefits of long-term TRT include preservation of lean muscle mass and bone mineral density. Testosterone plays a crucial role in preventing osteoporosis, particularly important as men age. Some evidence suggests beneficial effects on body composition, with reduced fat mass and increased muscle mass, though lifestyle factors remain paramount. For men with osteoporosis risk factors or previous fragility fractures, DEXA scanning may be recommended to monitor bone health.

Potential risks associated with long-term use require ongoing vigilance:

• Polycythaemia: Elevated red blood cell count requiring monitoring and possible dose adjustment or venesection

• Prostate health: Current evidence does not show increased prostate cancer incidence when appropriately selected and monitored; however, TRT is contraindicated in known or suspected prostate or male breast cancer

• Cardiovascular considerations: Evidence remains uncertain; men with pre-existing cardiovascular disease require individualised risk-benefit assessment

• Sleep apnoea: May be exacerbated in predisposed individuals

• Fluid retention: Caution in severe cardiac, hepatic or renal disease

• Other effects: Gynaecomastia, acne, alopecia, and hypertension can occur

• Drug interactions: May affect oral anticoagulants and antidiabetic medications

• Fertility suppression: Prolonged use may make recovery of sperm production more difficult

UK guidance emphasises that long-term TRT should only continue if there is clear clinical benefit and regular monitoring confirms safety. Annual reviews should reassess symptoms, treatment goals, and whether benefits continue to outweigh risks. The decision to continue long-term treatment should remain dynamic, responsive to your changing health status, and always made collaboratively with your healthcare team.

If you experience any suspected side effects from Testogel, report them via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

Frequently Asked Questions