When you are diagnosed with low testosterone and begin discussing treatment options, one of the first decisions you and your clinician will need to make is how testosterone will be delivered into your body. For most men in the UK, this comes down to two primary options: topical testosterone gel or injectable testosterone.
Both methods are clinically effective. Both are widely prescribed. And both have a strong evidence base supporting their use in treating hypogonadism. But they are fundamentally different experiences to live with, and the right choice depends on factors that are deeply personal — your daily routine, your comfort with needles, who you share physical space with, and how your body responds to each method.
This is not a decision where one option is objectively better than the other. It is about finding the method that fits your life well enough that you will use it consistently, because consistency is what makes TRT work. This guide provides an honest, evidence-based comparison to help you make that decision.
Understanding Testosterone Gel
Testosterone gel is a topical preparation that is applied directly to the skin, typically once daily. The testosterone is absorbed through the skin into the bloodstream over several hours, providing a steady supply throughout the day. In the UK, the two most commonly prescribed testosterone gels are Testogel (available in sachets or a metered-dose pump) and Tostran (available in a metered-dose canister).
Testogel: Contains testosterone in an alcohol-based gel. The standard dose is one 50mg sachet applied daily, though doses can be adjusted based on blood test results. The pump dispenser version allows for more precise dose adjustments. Testogel is applied to clean, dry skin on the shoulders, upper arms, or abdomen.
Tostran: A 2% testosterone gel in a metered-dose canister. Each actuation delivers 10mg of testosterone, allowing for flexible dose adjustments in 10mg increments. It is applied to the abdomen, inner thighs, or upper arms.
Both gels work on the same principle: testosterone is absorbed through the skin and enters the bloodstream gradually, mimicking the body’s natural daily testosterone rhythm more closely than some injection schedules. Application typically takes two to three minutes, and the gel dries within five to ten minutes.
Understanding Injectable Testosterone
Injectable testosterone delivers the hormone directly into muscle tissue (intramuscular) or fatty tissue beneath the skin (subcutaneous), from where it is gradually absorbed into the bloodstream. The NHS and private clinics across the UK prescribe several injectable formulations, with the most common being Sustanon 250 (a blend of four testosterone esters, typically injected every two to four weeks), Nebido (testosterone undecanoate, injected every ten to fourteen weeks), and testosterone cypionate or enanthate (typically injected once or twice weekly).
The injection frequency and formulation significantly affect the experience. Weekly or twice-weekly injections of cypionate or enanthate tend to produce the most stable blood levels, while less frequent Sustanon or Nebido injections may result in more noticeable peaks and troughs.
Absorption and Blood Level Stability
This is one of the most important clinical differences between the two methods, and it affects how you feel day to day.
Testosterone gel produces relatively stable blood levels when applied consistently at the same time each day. Testosterone levels typically peak two to six hours after application and then gradually decline. Because you apply the gel every day, levels remain within a fairly narrow range, which can reduce the mood and energy fluctuations that some men experience with less frequent injection schedules.
However, absorption through the skin is inherently variable. Factors such as skin thickness, body hair density, sweating, and application technique can all influence how much testosterone actually reaches the bloodstream. Studies show that absorption rates from topical testosterone can vary by 10 to 30 percent between individuals, and even within the same individual from day to day. This variability means that some men achieve excellent blood levels on a standard gel dose, while others absorb poorly and may need higher doses or a switch to injections.
Injectable testosterone delivers a known quantity of testosterone directly into the body, which makes dosing more predictable. However, the blood level pattern depends heavily on the injection frequency. With frequent injections (once or twice weekly using cypionate or enanthate), blood levels are remarkably stable — often more stable than daily gel application. With less frequent injections (Sustanon every three to four weeks, or Nebido every ten to fourteen weeks), there are more pronounced peaks and troughs, which some men experience as a cycle of feeling good after injection and then noticing symptoms creeping back before their next dose.
The clinical takeaway is nuanced: daily gel can provide stable levels but with variable absorption, while frequent injections can provide both stable and predictable levels, but less frequent injection schedules introduce cyclical variation that some men find problematic.
Lifestyle Considerations: The Daily Reality
This is where the practical differences between gel and injections become most relevant, and where many men ultimately make their decision.
Living with Testosterone Gel
Daily routine impact: Applying testosterone gel adds approximately five minutes to your morning routine. You apply it after showering, allow it to dry, and then get dressed. This needs to happen at roughly the same time each day for optimal results.
Transfer risk: This is the single most significant lifestyle consideration with testosterone gel, and it deserves honest discussion. Testosterone gel can transfer to other people through skin-to-skin contact. This is particularly concerning for female partners and children, who can experience adverse effects from testosterone exposure, including virilisation symptoms in women (deepening of voice, facial hair growth) and premature puberty in children.
To minimise transfer risk:
- Apply gel only to areas that will be covered by clothing
- Wash your hands thoroughly after application
- Allow the gel to dry completely before dressing
- Cover application areas with clothing before close contact with others
- Shower or wash application areas before intimate skin contact
For men with young children or partners who are pregnant or trying to conceive, the transfer risk of testosterone gel is a serious consideration that may tip the balance toward injections.
Exercise and swimming: You should avoid showering, swimming, or heavy sweating for at least two hours (ideally four to six hours) after applying testosterone gel, as this can wash off or reduce absorption. For men who exercise in the morning, this may require adjusting their routine.
Travel: Gel sachets and pumps are easy to travel with, though carrying them through airport security may occasionally require explanation. There is no need to transport needles or sharps bins.
Living with Testosterone Injections
Routine impact: Rather than a daily commitment, injections require a few minutes once or twice a week (for cypionate or enanthate), every two to four weeks (for Sustanon), or every ten to fourteen weeks (for Nebido). Between injections, there is no daily treatment-related routine.
No transfer risk: Once injected, the testosterone is sealed within your body. There is no risk of transferring testosterone to partners, children, or anyone else through physical contact. For many men, this is the decisive advantage of injections.
Injection anxiety: Fear of needles is a genuine barrier for some men, and it should not be dismissed. However, most men who start self-injecting report that their anxiety diminishes substantially within the first few weeks. Subcutaneous injection with very fine needles (29 gauge) is particularly well-tolerated. If needle anxiety is severe, your clinician may recommend strategies to manage this, or you may prefer clinic-administered injections.
Travel: Travelling with injectable testosterone requires more planning. You will need to carry your medication, needles, syringes, alcohol swabs, and a sharps container. When flying, you should carry a letter from your prescribing clinician confirming your need for injectable medication. Different countries have different regulations regarding travelling with controlled substances, and testosterone is a controlled drug in the UK (Class C, Schedule 4 Part II).
Storage: Injectable testosterone should be stored at room temperature and protected from light. It does not require refrigeration, making storage straightforward.
Cost Comparison in the UK
Cost can be a meaningful factor, particularly for men accessing TRT privately.
On the NHS: If your GP or endocrinologist prescribes TRT through the NHS, you will pay the standard prescription charge in England (currently £9.90 per item, or free if you qualify for exemptions). In Scotland, Wales, and Northern Ireland, prescriptions are free. The NHS most commonly prescribes Sustanon 250 or Testogel, and the cost to you as a patient is the same regardless of which is prescribed.
Through private clinics: Costs vary considerably between providers and formulations. As a general guide:
- Testosterone gel (Testogel/Tostran): Typically £30 to £60 per month
- Sustanon 250: Typically £10 to £30 per month (one of the least expensive options)
- Testosterone cypionate/enanthate: Typically £30 to £70 per month, depending on the supplier and dosing
- Nebido: Typically £80 to £120 per injection (approximately £30 to £50 per month when averaged over the injection cycle)
These figures are approximate and do not include consultation fees, blood test costs, or other associated expenses that most private TRT clinics charge. It is worth asking any provider for a full breakdown of ongoing costs before committing to treatment.
Effectiveness: Does One Method Work Better?
In clinical terms, both testosterone gel and injections are effective at restoring testosterone levels to the normal physiological range and relieving symptoms of hypogonadism. Large-scale studies and clinical experience confirm that neither method is inherently superior in terms of symptom relief when blood levels are adequately maintained.
However, individual response varies. Some men achieve excellent blood levels and symptom relief on gel but respond poorly to injections, or vice versa. This is influenced by factors including skin absorption characteristics, injection site absorption rates, individual metabolism, and SHBG (sex hormone-binding globulin) levels.
The British Society for Sexual Medicine (BSSM) guidelines recommend that the choice of testosterone formulation should be a shared decision between clinician and patient, taking into account individual preferences, lifestyle factors, and clinical response.
In practice, if one method is not achieving satisfactory results, switching to the other is a reasonable and common approach. Many men who start on gel eventually move to injections (often because of absorption variability or transfer concerns), while some men who start on injections switch to gel (typically because of injection fatigue or a preference for daily application over periodic injections).
Switching Between Methods
Switching from one testosterone delivery method to another is straightforward and is done routinely in clinical practice. If you are currently using gel and want to switch to injections, or vice versa, your clinician will manage the transition to minimise any gap in coverage.
Gel to injections: Typically, you apply your last dose of gel and begin injections within one to two days. Your clinician may adjust the timing based on the specific injection formulation.
Injections to gel: You begin daily gel application around the time your next injection would have been due (or slightly before, depending on the formulation). Blood tests are usually performed four to six weeks after the switch to confirm adequate levels on the new method.
Switching methods does not reset your TRT progress. The testosterone in your system does not distinguish between how it was delivered, so the therapeutic benefits you have built up will continue as long as your blood levels remain within the target range.
Other Delivery Methods Worth Mentioning
While gel and injections are by far the most commonly prescribed TRT methods in the UK, other options exist:
Testosterone patches (Intrinsa was discontinued, but others may be available): Adhesive patches that deliver testosterone through the skin. Less commonly used due to skin irritation, adhesion problems, and limited availability in the UK.
Testosterone implants (pellets): Small pellets inserted under the skin every four to six months that release testosterone slowly. Available through some specialist clinics but not widely used in the UK.
Oral testosterone (testosterone undecanoate capsules): Available but less commonly prescribed due to variable absorption and the need for twice-daily dosing with fatty meals.
Nasal testosterone (Natesto): Applied inside the nose three times daily. Not widely available in the UK and the frequent dosing can be inconvenient.
Making Your Decision
There is no universally correct answer. The best TRT method is the one you will use consistently and that fits into your life without becoming a source of stress. Consider these factors honestly:
- Choose gel if: You are comfortable with a daily routine, you do not have young children at home or can reliably manage transfer risk, you prefer to avoid needles, and your skin absorbs testosterone well (confirmed by blood tests).
- Choose injections if: You prefer less frequent dosing, you have children or a partner where transfer risk is a concern, you want predictable dosing without absorption variability, you are comfortable with self-injection or willing to learn, or you have tried gel and not achieved adequate blood levels.
Many men benefit from trying one method, monitoring their blood levels and symptom response, and then switching if it is not working optimally. A good TRT provider will support this process rather than locking you into a single approach.
At Evernu, we work with patients to find the testosterone delivery method that best suits their clinical needs and lifestyle. As a RQIA-regulated healthcare provider serving men across England, Scotland, Wales, and Northern Ireland, we offer personalised TRT protocols with comprehensive blood monitoring and ongoing clinical support.
If you are considering TRT or want to discuss whether a different delivery method might suit you better, explore our testosterone treatment options or take our free online assessment to get started.
Frequently Asked Questions
Can I use testosterone gel and injections together?
Combination therapy is not standard practice. Most men use one delivery method at a time. However, in rare cases, a clinician might recommend a short overlap during a transition from one method to another, or use a small amount of daily gel to supplement a long-acting injection like Nebido toward the end of its cycle when levels are declining. This should only be done under direct clinical supervision with appropriate blood monitoring.
Will my GP prescribe my preferred method?
NHS prescribing guidelines typically favour Sustanon 250 or Testogel as first-line options, as these are the most cost-effective. If you have a preference for a specific formulation, your GP may be willing to prescribe it, but this varies by practice and local prescribing policy. If your preferred method is not available through the NHS, private TRT clinics can usually offer a wider range of options. In Northern Ireland, Scotland, and Wales, prescribing patterns may differ slightly from England.
How do I know if my gel is absorbing properly?
The only reliable way to check absorption is through blood tests. Your clinician should check your testosterone levels approximately four to six weeks after starting gel treatment or changing the dose. Blood should be drawn in the morning, ideally two to four hours after gel application, when levels are expected to peak. If your levels are below the target range despite consistent application at an adequate dose, poor absorption may be the cause, and switching to injections should be considered.
Is the transfer risk with testosterone gel really that serious?
Yes, it should be taken seriously. Published case reports have documented virilisation in female partners and precocious puberty in children exposed to testosterone gel through skin contact. The risk is highest with direct, prolonged skin-to-skin contact on areas where gel has been applied, but residual testosterone can also transfer via shared bedding or clothing. With proper precautions (covering application areas, hand washing, showering before intimate contact), the risk can be effectively managed, but it requires consistent diligence.
If I start with gel, how easy is it to switch to injections later?
Very easy. Switching between delivery methods is common and clinically straightforward. Your clinician will advise on the timing of the transition to ensure continuous coverage. You will not lose any of the benefits you have built up on gel. Blood tests are typically performed four to six weeks after switching to confirm that the new method is achieving target testosterone levels. Many men switch methods at some point during their TRT journey, and this is considered a normal part of optimising treatment.
This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting or changing any medication. Evernu is regulated by the Regulation and Quality Improvement Authority (RQIA).
