Your GP orders bloodwork. They test TSH and nothing else. "Your thyroid is fine," they say, and discharge you. You still feel chronically tired, your recovery is poor, and your body isn't responding to training. The bloodwork they ran told you almost nothing.
Most GPs operate within a cost-containment model. They test the minimum required to rule out obvious pathology. They don't test for optimisation. If you want to understand your hormonal health, you need to know what to test, where to get tested in the UK, and what the reference ranges actually mean.
The Complete Hormone Panel
Total Testosterone (TT)
- Method: Immunoassay or liquid chromatography-mass spectrometry (LC-MS)
- Reference range: 10–30 nmol/L (UK labs)
- Optimal: 18–25 nmol/L
- Why it matters: The headline number, but meaningless without SHBG and free T.
Free Testosterone (FT)
- Method: Calculated using Vermeulen formula (not direct measurement; labs should do this)
- Reference range: 0.3–1.0 nmol/L
- Optimal: 0.6+ nmol/L
- Why it matters: The number that actually correlates with symptoms. Always demand this if it's not reported.
Sex Hormone-Binding Globulin (SHBG)
- Reference range: 10–57 nmol/L
- Optimal: 15–35 nmol/L
- Why it matters: Controls bioavailability of both testosterone and oestradiol. High SHBG suppresses free T even with normal total T.
Luteinising Hormone (LH)
- Reference range: 2–9 mIU/L
- Optimal: 3–6 mIU/L
- Why it matters: Stimulates testosterone production. Low LH with low testosterone suggests secondary hypogonadism. Normal LH with low T suggests primary testicular failure.
Follicle-Stimulating Hormone (FSH)
- Reference range: 1–7 mIU/L
- Optimal: 2–5 mIU/L
- Why it matters: Stimulates spermatogenesis. Low FSH with low testosterone indicates central hypogonadism.
Oestradiol (E2)
- Method: LC-MS preferred (immunoassay can be unreliable in men)
- Reference range: 0–150 pmol/L (varies by lab)
- Optimal: 50–100 pmol/L
- Why it matters: Too high suppresses testosterone production; too low damages bone and sexual function. Must be interpreted with testosterone.
Prolactin
- Reference range: <480 mIU/L
- Why it matters: Elevated prolactin suppresses dopamine, which suppresses GnRH, crashing testosterone. Also causes erectile dysfunction directly.
DHEA-S (Dehydroepiandrosterone Sulphate)
- Reference range: 1.8–6.2 µmol/L (age-dependent)
- Why it matters: A functional marker of adrenal reserve. Low DHEA-S suggests chronic stress or adrenal insufficiency. Useful for understanding the broader endocrine picture.
Essential Metabolic Markers
Fasting Glucose
- Reference range: 3.5–5.5 mmol/L
- Optimal: < 5.0 mmol/L
- Why it matters: Insulin resistance (high fasting glucose) drives SHBG down and visceral fat accumulation up. Directly undermines testosterone and metabolic health.
Haemoglobin A1c (HbA1c)
- Reference range: <42 mmol/mol (< 6.0%)
- Optimal: < 39 mmol/mol (< 5.7%)
- Why it matters: 3-month average of blood glucose. More informative than fasting glucose alone. Rising HbA1c is an early warning sign of metabolic dysfunction.
Lipid Panel
- Total cholesterol, LDL, HDL, triglycerides
- Why it matters: Chronic high triglycerides and low HDL indicate insulin resistance and systemic inflammation, both of which suppress testosterone. Statins can also lower testosterone, though modestly.
Liver Function (ALT, AST, GGT, Bilirubin)
- ALT/AST: 10–40 IU/L
- GGT: < 60 IU/L
- Why it matters: The liver synthesises SHBG and metabolises oestrogen. Elevated liver enzymes indicate hepatic stress (fatty liver disease, alcohol damage) that directly impacts hormone metabolism.
Full Blood Count (FBC)
- Haemoglobin, haematocrit, white cell count, platelet count
- Why it matters: Anaemia reduces oxygen delivery and impairs testosterone synthesis. Elevated white cells suggest chronic inflammation. Polycythaemia (high haematocrit) can occur with TRT and requires monitoring.
UK Reference Ranges vs. Optimal Ranges
This is where most men get confused. Reference ranges are population normals—the middle 95% of tested men. They don't account for:
- Age differences (a 25-year-old's optimal T is higher than a 55-year-old's)
- Symptom correlation (many men in the reference range still have symptoms of low T)
- Individual variation (one man feels good at 15 nmol/L total T, another needs 22+)
Use population reference ranges to rule out obvious pathology. Use optimal ranges to actually feel good.
A 45-year-old man with total T of 12 nmol/L, free T of 0.25 nmol/L, and SHBG of 50 nmol/L is technically "within reference range" by some UK labs' definitions. He will almost certainly have fatigue, mood issues, and erectile dysfunction. His bloods told him nothing useful.
Where to Test in the UK
Your GP (NHS)
- Cost: Free
- What they test: Usually just TSH, sometimes a basic metabolic panel
- Turnaround: 1–2 weeks
- Limitations: Won't test free testosterone, SHBG, or oestradiol unless you're already on TRT or have obvious symptoms. Restricted to diagnosing pathology, not optimisation.
Private Blood Test Companies These allow self-referral and are affordable:
- Medichecks (medichecks.com): Comprehensive testosterone panels from £50–120. Fast turnaround (48–72 hours). Reliable for UK testing.
- Monitor My Health (monitorhealth.co.uk): Similar pricing and turnaround. Good for repeated testing.
- Randox at-home collection (randox.com): Full hormonal panels via post. Slightly more expensive (£150–250) but reputable.
All three send results direct to you, with interpretation guides. Most will flag obviously abnormal results but won't interpret them in context of your symptoms.
Private Clinics (Consultation-Based)
- Cost: £150–400 for initial consultation, £100–250 for bloodwork
- Turnaround: 1–2 weeks
- Advantage: A clinician interprets results and advises on intervention.
- Examples: menopause/hormone specialists, private GPs, TRT clinics
Use these if your results are abnormal or confusing, or if you're considering intervention (TRT, lifestyle modification) and want medical oversight.
Reading Your Results: A Worked Example
Let's say a 48-year-old man gets these results:
Total testosterone: 16 nmol/L (reference 10–30, so "normal") Free testosterone: 0.28 nmol/L (reference 0.3–1.0, so technically low-normal) SHBG: 52 nmol/L (reference 10–57, so technically "normal") LH: 4.2 mIU/L (reference 2–9, "normal") FSH: 3.1 mIU/L (reference 1–7, "normal") Fasting glucose: 5.8 mmol/L (reference < 5.5, slightly elevated)
Clinical interpretation:
- The total T is low-normal; combined with age, this is concerning.
- Free T is barely in range—functionally low for this age.
- SHBG is elevated (52 is high-normal), which is suppressing free T despite respectable total T.
- LH and FSH are adequate, suggesting the issue is lifestyle/metabolic, not primary testicular failure.
- Fasting glucose is trending high, suggesting early insulin resistance, which drives SHBG up.
Likely interventions:
- Weight loss and improved insulin sensitivity (the fasting glucose is the key clue)
- Address any alcohol consumption
- Optimise sleep
- If symptoms are severe, TRT might be discussed, but first address the metabolic issues
A doctor who only reads "testosterone is normal" and dismisses the man will have missed the entire story.
When to See a Private Clinic
- Your GP refuses to investigate or trivialises your symptoms
- Your results are abnormal but your GP has no interpretation
- You're considering TRT and need proper assessment and monitoring
- You want optimisation beyond what NHS medicine typically offers
A private GP or hormone specialist will be more likely to:
- Order the full panel (free T, SHBG, oestradiol, prolactin, LH, FSH)
- Consider your age-adjusted ranges
- Correlate bloodwork with symptoms
- Monitor you properly if you pursue intervention
The Bottom Line
Your bloodwork is your own. Request it, interpret it in context, and don't accept incomplete testing. A single total testosterone number without SHBG and free T is not bloodwork—it's theatre.
Most men over 40 should have a baseline full hormone panel, fasting glucose, HbA1c, lipids, and liver function checked once per year. If you're optimising seriously, twice yearly is reasonable.
Get tested. Know your numbers. Act accordingly.
References:
Vermeulen A, Verdonck L, Kaufman JM. A critical evaluation of simple methods for the estimation of free androgens in serum. J Clin Endocrinol Metab. 1999;84(10):3666-72.