TRT in the UK 2026: A Sports Medicine Physician’s Complete Guide to Testosterone Replacement Therapy

What Is Testosterone Replacement Therapy (TRT)?

Testosterone Replacement Therapy (TRT) is a medically supervised protocol that restores physiological testosterone levels in men whose endogenous production has declined below the clinical threshold for hypogonadism. In the UK, a diagnosis of hypogonadism typically requires a fasting morning total testosterone below 12 nmol/L on two separate measurements, accompanied by characteristic symptoms including fatigue, reduced libido, erectile dysfunction, loss of muscle mass, and mood disturbance.

As a Sports Medicine Physician practising in Manchester, I see a growing number of men — particularly those aged 35 to 55 who are active in gym and bodybuilding communities — who arrive presenting both clinical symptoms of low testosterone and a history of prior anabolic steroid use. This overlap makes assessment more complex, but the fundamentals of TRT remain the same regardless of history.

How TRT Is Prescribed in the UK (NHS vs Private)

On the NHS, TRT is available via your GP following a referral to endocrinology or urology if two morning testosterone bloods confirm hypogonadism. The most commonly prescribed preparations in the UK are testosterone gel (Testogel, Tostran) and testosterone undecanoate injections (Nebido, administered every 10–14 weeks). Testosterone enanthate is also used in some NHS Trusts on a more frequent injection schedule.

Private TRT clinics in the UK — several of which are registered with the Care Quality Commission (CQC) — offer a more responsive pathway, often prescribing testosterone cypionate or enanthate on weekly or bi-weekly self-injection protocols that more closely mirror physiological pulsatility. These are entirely legal when prescribed by a licensed UK medical practitioner.

The MHRA (Medicines and Healthcare products Regulatory Agency) regulates all testosterone preparations in the UK. Using testosterone without a valid prescription from a registered UK prescriber constitutes a criminal offence under the Misuse of Drugs Act 1971 (Class C).

TRT Dosing: What Clinical Practice Looks Like in 2026

For most men on TRT, the clinical goal is to achieve trough levels (pre-injection) of 15–25 nmol/L — mid-normal range — rather than to push levels to the ceiling of normal. Standard starting protocols I use in clinical practice:

• Testosterone enanthate or cypionate: 125–150 mg subcutaneous or intramuscular injection every 7 days. This produces stable levels with minimal peaks and troughs compared to fortnightly injections.
• Testosterone undecanoate (Nebido): 1000 mg IM every 10–14 weeks. Convenient but produces wider level fluctuations — less popular with active patients.
• Testosterone gel: Daily application. Good tolerability, but absorption variability and transfer risk to partners/children are important considerations.

Monitoring on TRT: What Your Bloods Should Show

Any responsible TRT protocol requires regular blood monitoring. At minimum, this means total testosterone, haematocrit, full blood count, PSA (prostate-specific antigen in men over 40), oestradiol, and LH/FSH (to confirm suppression). Liver function testing is relevant if oral testosterone preparations are used, though these are rarely prescribed in the UK.

Haematocrit is the parameter I watch most closely. Exogenous testosterone stimulates erythropoiesis, and haematocrit above 54% significantly increases thromboembolic risk. If this occurs, therapeutic phlebotomy or dose reduction is required.

TRT and Fertility

TRT suppresses the hypothalamic-pituitary-gonadal (HPG) axis. Men wishing to preserve fertility should be counselled that TRT will reduce sperm production — often dramatically. In these cases, alternatives such as clomiphene citrate (off-label) or human chorionic gonadotropin (HCG) to stimulate endogenous testosterone production may be preferable, as these preserve the HPG axis.

The Bottom Line

TRT, when properly prescribed and monitored by a qualified UK clinician, is a safe and highly effective intervention for men with confirmed hypogonadism. The key is clinical supervision, regular blood monitoring, and using licensed preparations from regulated UK pharmacies. If you suspect you may have low testosterone, your first step should always be a consultation with your GP or a CQC-registered TRT clinic.