How much does Testogel increase testosterone? This is a common question for men considering or starting testosterone replacement therapy (TRT) for hypogonadism. Testogel, a transdermal gel licensed in the UK, delivers testosterone through the skin to restore levels into the normal physiological range. The degree of increase varies considerably between individuals, influenced by factors including baseline testosterone, skin characteristics, application technique, and formulation used. Understanding what to expect from Testogel treatment—including typical testosterone increases, monitoring requirements, and timelines for symptom improvement—is essential for safe and effective therapy. This article provides evidence-based guidance aligned with UK clinical practice.

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 is available in two formulations: Testogel 16.2 mg/g gel (supplied as a metered-dose pump) and Testogel 1% (50 mg/5 g) gel (supplied in sachets). Both are applied daily to clean, dry, intact skin. The gel is absorbed through the skin, delivering testosterone directly into the bloodstream, thereby bypassing first-pass hepatic metabolism and providing more stable serum levels compared to oral formulations.

The mechanism of action involves passive diffusion of testosterone across the stratum corneum into the dermal capillaries. Once absorbed, testosterone circulates bound to sex hormone-binding globulin (SHBG) and albumin, with a small fraction remaining as free (bioactive) testosterone. This bioavailable testosterone then exerts its effects on androgen receptors throughout the body, supporting muscle mass, bone density, libido, mood, and energy levels.

Application sites differ by formulation: Testogel 16.2 mg/g pump should be applied to the shoulders and upper arms only, whereas Testogel 1% sachets may be applied to the shoulders, upper arms, or abdomen. Neither formulation should be applied to the genitals or broken skin. After application, allow the gel to dry fully (approximately 3–5 minutes), then cover the area with clothing. Wash your hands thoroughly with soap and water immediately after application to prevent accidental transfer to others, particularly women and children. Avoid washing, showering, or swimming for at least 2 hours after application to ensure adequate absorption. The gel is flammable until dry; avoid flames, smoking, or sparks during and immediately after application.

Dosing varies by formulation: The 16.2 mg/g pump typically starts at 40.5 mg testosterone daily (two pump actuations), adjusted by 20.25 mg increments to a maximum of 81 mg daily. The 1% sachet formulation typically starts at 50 mg daily (one 5 g sachet), adjusted in 25 mg steps to a maximum of 100 mg daily. Prescribing should follow NICE guidance and British Society for Sexual Medicine (BSSM) recommendations, ensuring patients are appropriately assessed following confirmed biochemical hypogonadism (low serum testosterone on two separate morning samples) alongside appropriate clinical symptoms.

Testogel is contraindicated in men with prostate cancer, male breast cancer (current or suspected), severe cardiac insufficiency, severe hepatic or renal impairment, and uncontrolled hypertension. Caution is required in men with conditions predisposing to oedema (e.g., heart failure, treatment with ACTH or corticosteroids) and in those with obstructive sleep apnoea (OSA), as testosterone may worsen these conditions. Patients should be counselled regarding application technique, potential adverse effects, and the importance of avoiding skin-to-skin contact with others to prevent unintended testosterone transfer. If you experience any side effects, report them via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

Expected Testosterone Increases with Testogel Treatment

The extent to which Testogel increases serum testosterone levels varies considerably between individuals. In men with confirmed hypogonadism (baseline testosterone typically below the lower limit of the laboratory's adult male reference range, often <12 nmol/L), Testogel can raise serum testosterone into the normal physiological range within days to weeks of commencing treatment, provided the dose is appropriate and application technique is correct.

Clinical trial data show that appropriate dosing of Testogel typically restores testosterone levels to within the mid-normal range of the laboratory's reference interval (commonly approximately 15–30 nmol/L for adult males, though this varies by assay). Individual responses vary widely due to differences in skin permeability, application site, body composition, baseline testosterone levels, and adherence to application instructions. Some men may require dose adjustments—either upward or downward—to achieve target testosterone levels.

Formulation-specific dosing is important: The Testogel 16.2 mg/g pump delivers 20.25 mg testosterone per actuation, with a starting dose typically 40.5 mg daily (two actuations), adjustable by 20.25 mg increments to a maximum of 81 mg daily. The Testogel 1% sachet formulation starts at 50 mg daily (one 5 g sachet), adjustable in 25 mg steps to a maximum of 100 mg daily. Higher doses may bring levels into the mid-to-upper normal range, though this must be balanced against the risk of supraphysiological levels and associated adverse effects, including polycythaemia and cardiovascular risks.

It is important to note that Testogel does not produce a fixed, predictable increase in every patient. The goal of TRT is not to achieve supranormal testosterone levels, but rather to restore physiological concentrations that alleviate symptoms of hypogonadism while minimising risks. Target levels are generally considered to be in the mid-normal range within the laboratory's adult male reference interval, according to BSSM and European Association of Urology (EAU) guidelines, with treatment individualised to symptom relief and safety monitoring.

Regular monitoring and dose titration, guided by both biochemical results (taken at the correct time relative to application, as specified in the product information) and clinical response, are essential components of safe and effective Testogel therapy.

Factors That Affect How Much Testogel Raises Testosterone

Multiple factors influence the degree to which Testogel increases serum testosterone, and understanding these variables is crucial for optimising treatment outcomes. Skin characteristics play a significant role: individuals with thicker skin, higher subcutaneous fat, or certain dermatological conditions may experience reduced absorption. Conversely, thinner skin or increased vascularity at the application site can enhance testosterone uptake.

Application technique is critical. Testogel should be applied to the correct site for the formulation being used: Testogel 16.2 mg/g pump to shoulders and upper arms only; Testogel 1% sachets to shoulders, upper arms, or abdomen. Apply to clean, dry, intact skin and allow the gel to dry fully (approximately 3–5 minutes) before dressing. Wash your hands thoroughly with soap and water immediately after application. Avoid washing, showering, or swimming for at least 2 hours after application, as doing so can significantly reduce absorption. Cover the application site with clothing once dry to prevent accidental transfer to others. Patients are advised to apply the gel at a consistent time each day to support adherence, though the timing does not significantly affect overall efficacy.

Body composition also matters: men with higher body mass index (BMI) or greater adiposity may exhibit altered pharmacokinetics, as adipose tissue can act as a reservoir for testosterone, potentially affecting serum levels. Hepatic and renal function can influence testosterone metabolism and clearance; Testogel is contraindicated in severe hepatic or renal impairment and should be used with caution in significant organ dysfunction.

Concomitant medications may interact with testosterone. Important interactions include:

• Anticoagulants (e.g., warfarin): Testosterone may potentiate the effects of coumarin-type anticoagulants; monitor INR closely and adjust anticoagulant dose as needed.

• Antidiabetic medications (insulin, oral hypoglycaemics): Testosterone may improve insulin sensitivity and lower blood glucose; monitor glucose levels and adjust antidiabetic therapy accordingly.

• ACTH or corticosteroids: Concurrent use increases the risk of oedema and fluid retention; use with caution and monitor for signs of heart failure or worsening oedema.

SHBG levels, which vary with age, obesity, thyroid status, and liver disease, also affect the proportion of bioavailable testosterone, meaning two patients with identical total testosterone levels may experience different clinical responses. Genetic variation in androgen receptors and testosterone-metabolising enzymes (e.g., 5α-reductase, aromatase) may contribute to inter-individual variability, though these factors are not routinely assessed in clinical practice.

Clinicians should consider these factors when interpreting testosterone levels and adjusting Testogel dosing, always prioritising individualised care, correct application technique, and patient-reported outcomes alongside biochemical targets.

Monitoring Your Testosterone Levels During Treatment

Regular monitoring of serum testosterone is a cornerstone of safe and effective Testogel therapy. UK guidance recommends checking testosterone levels approximately 2–6 weeks after initiating treatment or following any dose adjustment, as steady-state levels are typically achieved within this timeframe. The timing of blood sampling relative to gel application should follow the specific instructions in the product information for your formulation, as requirements differ between Testogel 16.2 mg/g pump and Testogel 1% sachets. Blood samples should ideally be taken in the morning (before 11:00 AM) to align with the natural circadian rhythm of testosterone secretion.

The target testosterone range is generally the mid-normal range within your laboratory's adult male reference interval (commonly approximately 15–25 nmol/L, though reference ranges vary by assay). Treatment should be individualised to alleviate symptoms while remaining within the normal reference range and minimising risks. Dose titration is formulation-specific: for Testogel 16.2 mg/g pump, adjust by 20.25 mg increments to a maximum of 81 mg daily; for Testogel 1% sachets, adjust in 25 mg steps to a maximum of 100 mg daily. If levels are supraphysiological (above the upper limit of the reference range) or if adverse effects emerge, dose reduction is warranted.

Beyond testosterone, additional monitoring parameters are essential:

• Full blood count (FBC): Check at baseline, then at 3 months, 6 months, and 12 months in the first year, then annually thereafter, to monitor for polycythaemia—a known adverse effect of testosterone therapy characterised by elevated haematocrit. If haematocrit exceeds 0.54, consider dose reduction or temporary cessation and refer to haematology if levels remain elevated.

• Prostate-specific antigen (PSA) and digital rectal examination (DRE): Recommended at baseline and during early follow-up (e.g., within 3–12 months), then according to UK age-specific PSA guidance. Testosterone therapy is contraindicated in prostate cancer. Refer to urology if PSA is above age-specific reference ranges, rising rapidly (>0.4 ng/mL per year or >20% per year), or if DRE is abnormal.

• Liver function tests (LFTs) and lipid profiles: Consider monitoring if clinically indicated, as testosterone can influence hepatic function and cardiovascular risk factors, although transdermal formulations like Testogel are generally considered safer than oral preparations.

• Blood pressure and cardiovascular assessment: Monitor regularly, as testosterone may affect blood pressure and fluid retention.

Patients should be encouraged to report any symptoms suggestive of adverse effects, including:

• Application-site reactions (rash, irritation)

• Oedema or fluid retention

• Mood changes, irritability, or aggression

• Acne or oily skin

• Gynaecomastia (breast enlargement or tenderness)

• Lower urinary tract symptoms

• Worsening of obstructive sleep apnoea (increased snoring, daytime sleepiness)

Attend regular follow-up appointments to ensure treatment remains appropriate and effective. Report any suspected side effects via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

When to Expect Results from Testogel

The timeline for experiencing clinical benefits from Testogel varies depending on the symptom being addressed, and patients should be counselled on realistic expectations to promote adherence and satisfaction with treatment. Serum testosterone levels typically begin to rise within 24–48 hours of the first application, with steady-state concentrations achieved after approximately 2–4 weeks of consistent daily use. However, biochemical normalisation does not always correlate immediately with symptomatic improvement.

Libido and sexual function are often among the first symptoms to improve, with many men reporting enhanced sexual desire and erectile function within 3–6 weeks of starting Testogel. However, the response is variable, and some individuals may require 3–6 months to experience maximal benefit, particularly if there are coexisting psychological or vascular factors contributing to sexual dysfunction.

Energy levels and mood typically improve within 4–8 weeks, though some men notice changes sooner. Patients often describe feeling more motivated, less fatigued, and experiencing improved overall well-being. Muscle mass and strength require longer to respond, with noticeable gains generally emerging after 3–6 months of treatment, particularly when combined with resistance exercise. Similarly, bone mineral density improvements, which are important for reducing fracture risk in hypogonadal men, take 12–24 months or longer to manifest and require ongoing therapy.

Body composition changes, such as reductions in fat mass, also occur gradually over 6–12 months. It is important to emphasise that Testogel is not a rapid solution, and patience is required to achieve optimal outcomes. If symptoms fail to improve after 6 months of treatment despite achieving target testosterone levels within the normal range, alternative diagnoses or contributing factors should be explored. These may include depression, obstructive sleep apnoea, metabolic syndrome, thyroid disorders, or medications that affect mood, energy, or sexual function.

Patients should be advised to contact their GP if they experience no improvement in symptoms after 3–6 months, develop adverse effects, or have concerns about their treatment. Regular follow-up and open communication between patient and clinician are essential to ensure Testogel therapy remains safe, effective, and aligned with individual health goals. Report any suspected side effects via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

Frequently Asked Questions