Symptoms of Low Testosterone
| Category | Symptoms |
|---|---|
| Sexual | Low libido, erectile dysfunction, reduced ejaculate volume |
| Physical | Fatigue, muscle loss, increased body fat (especially abdominal), gynaecomastia |
| Cognitive | Depression, poor concentration, memory problems |
| Metabolic | Osteoporosis, increased cardiovascular risk, insulin resistance |
| Sleep | Insomnia, sleep apnoea (can both cause and result from low T) |
Blood Tests for Low Testosterone
| Test | Normal Range | Notes |
|---|---|---|
| Total testosterone | 10–33 nmol/L | Morning sample (6–10am) essential; 2 samples on different days if borderline |
| Free testosterone | 225–725 pmol/L | Bioavailable form; more accurate in obese or older men |
| LH (luteinising hormone) | 1–8 IU/L | Low LH = secondary hypogonadism (pituitary/hypothalamic cause) |
| FSH | 1–8 IU/L | Low FSH with low T suggests central cause |
| Prolactin | <400 mIU/L | Elevated prolactin suppresses testosterone |
| SHBG | 10–57 nmol/L | Binds testosterone — affects free testosterone calculation |
| FBC + CRP | Normal | Anaemia and inflammation reduce testosterone |
Timing is CriticalTestosterone follows a strong circadian rhythm — levels are 20–30% higher in the morning. Always test between 7–10am. An afternoon testosterone result cannot be used to diagnose hypogonadism.
Testosterone Replacement Therapy (TRT) Options
| Form | Frequency | Pros | Cons |
|---|---|---|---|
| Testosterone gel | Daily | Steady levels, easy to use | Transference risk to partners/children |
| Testosterone injection (short-acting) | Every 2–3 weeks | Cheap, effective | Peaks and troughs |
| Testosterone injection (long-acting) | Every 10–14 weeks | Stable levels | Clinic visit needed |
| Testosterone patches | Daily | Discreet | Skin reactions common |
| Testosterone pellets | Every 3–6 months | Very stable | Minor procedure to insert |
Does TRT cause prostate cancer?
Current evidence does not show TRT causes prostate cancer. However, TRT is contraindicated in men with known prostate or breast cancer. PSA is monitored on TRT.
Will TRT affect my fertility?
Yes — exogenous testosterone suppresses sperm production (by suppressing LH/FSH). Men wanting children should use clomiphene or hCG to stimulate natural testosterone production instead.
How quickly does TRT work?
Libido often improves within 3–6 weeks. Energy and mood within 1–3 months. Body composition changes (muscle gain, fat loss) take 3–6 months. Full benefit assessment at 6–12 months.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.