Bloodwork Explained for Men Over 40: What to Test, When, and What Your Results Mean

Most men I know have had their cholesterol checked. Maybe their blood pressure. And that's it. That's the entirety of their health data going into their 40s.

It's not enough. Not even close.

Your NHS GP, through no fault of their own, operates a reactive system. They're looking for disease markers, not optimisation data. When your testosterone comes back "in range," the conversation ends, even if "in range" means the same level as a 75-year-old man.

If you want to understand what's actually happening in your body, you need to go and get the data yourself.

Adam's Take

I got my first comprehensive panel at 38. I thought I was fine, training four times a week, sleeping reasonably well, eating decent food. My total testosterone came back at 11.2 nmol/L. That's technically "normal" by NHS standards. It's also in the bottom 20% for my age group. I had no idea until I saw the number. That single test changed how I approached the next five years.

Why Standard NHS Testing Falls Short

The NHS reference range for testosterone is roughly 8-32 nmol/L. That's an enormous range. A man at 32 nmol/L is at peak male vitality. A man at 8.5 nmol/L is symptomatic, exhausted, and losing muscle, but technically "normal."

The range was built to identify pathology, not to tell you where you should be. The goal here is different: understanding where you are relative to your optimal, not relative to the threshold for diagnosis.

Beyond testosterone, there are markers that most GPs won't routinely check but that have significant impact on how you feel, perform, and age. Getting all of them in one panel gives you a complete picture.

The Full Panel: What to Test

Here's what I'd call the essential panel for any man over 40 who wants real data:

Hormone Markers

Total Testosterone: the starting point, but not the full picture. Results below 15 nmol/L are worth investigating regardless of symptoms; below 12 nmol/L and symptoms are likely.

Free Testosterone: the fraction not bound to SHBG or albumin. This is what's actually available to your tissues. You can have reasonable total testosterone with very low free testosterone if your SHBG is elevated.

SHBG (Sex Hormone Binding Globulin): binds to testosterone, making it unavailable. High SHBG is common in men over 40 and is a major reason why some men have "normal" total testosterone but feel terrible. I've covered SHBG in depth separately, it's worth understanding fully.

LH (Luteinising Hormone): the signal from your pituitary that tells your testes to produce testosterone. If LH is low alongside low testosterone, the problem is upstream (pituitary/hypothalamus). If LH is high with low testosterone, the testes themselves aren't responding.

Oestradiol (E2): men produce oestrogen too, and it matters. Too low causes joint pain, poor libido, and cognitive issues. Too high (common in overweight men) suppresses testosterone production and causes water retention.

Prolactin: elevated prolactin suppresses both testosterone and libido. Worth checking once as a baseline.

DHT (Dihydrotestosterone): the more potent androgen, relevant for libido, hair loss, and prostate. Optional unless you're on TRT or have symptoms.

Metabolic Markers

HbA1c: three-month average blood glucose. More useful than fasting glucose alone for catching insulin resistance early. Insulin resistance is strongly associated with low testosterone; they reinforce each other in a vicious cycle.

Fasting Insulin: your NHS GP almost never checks this, but it's one of the earliest markers of metabolic dysfunction. Chronically elevated insulin drives SHBG down and oestrogen up, both bad for testosterone.

Fasting Glucose: standard, but read alongside HbA1c and fasting insulin for the complete metabolic picture.

Lipid Panel (Full): total cholesterol, LDL, HDL, triglycerides. Triglycerides are the most useful single marker for metabolic health; elevated levels indicate poor carbohydrate metabolism.

Key Vitamins and Minerals

Vitamin D (25-OH): over half of UK men are deficient, particularly in winter. Low vitamin D is directly associated with lower testosterone. The optimal range is 100-150 nmol/L, not the NHS deficiency threshold of 25 nmol/L. There's more on the vitamin D and testosterone connection here.

Zinc: essential for testosterone synthesis. Deficiency suppresses production. High-intensity exercise depletes zinc faster than diet replaces it in many men.

Ferritin (iron stores): low ferritin causes fatigue that's identical in presentation to low testosterone. Worth ruling out.

Thyroid (TSH + Free T3 + Free T4): an underactive thyroid suppresses everything: energy, metabolism, libido, and testosterone production.

Inflammation and Cardiovascular

hsCRP (high-sensitivity C-reactive protein): a sensitive marker of systemic inflammation. Chronic low-grade inflammation suppresses testosterone and accelerates ageing. Optimal is below 1.0 mg/L; above 3.0 mg/L is a clear signal to investigate.

Full Blood Count (FBC): catches anaemia, infections, and blood disorders that can masquerade as fatigue or cognitive decline.

What Optimal Looks Like vs "Normal"

Where to Get Tested in the UK

Your GP can order some of these, but getting a complete panel via the NHS requires persistent advocacy and often multiple appointments. Many markers (free testosterone, fasting insulin, hsCRP, SHBG) are simply not routinely offered.

Private blood testing services have changed this. You can now order a full male hormone panel online, have a blood draw at a local clinic, and receive results within 24-48 hours.

Medichecks is the service I'd point most men to. Their Male Hormone Blood Test covers total and free testosterone, SHBG, LH, FSH, oestradiol, prolactin, and DHEA-S in a single panel. Add their Essential Thyroid Panel and you have most of the hormone picture. They use an NHS-accredited lab, offer home phlebotomy, and results include a doctor's commentary on any out-of-range findings.

Recommended

Medichecks Male Hormone Blood Test

Full male hormone panel including total testosterone, free testosterone, SHBG, LH, FSH, oestradiol, and prolactin. NHS-accredited lab, results in 24-48 hours.

View Medichecks →

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For the broadest coverage, their Well Man Ultimate or Hormone and Performance Blood Test bundles include metabolic markers, vitamins, thyroid, and the full hormone panel. Worth the extra cost if this is your first panel.

Adam's Take

I've used Medichecks for my panels for the past few years. The home phlebotomist service is genuinely easy, they come to you, no GP referral needed, results land in your patient portal by the next morning in my experience. The commentary from their doctors is brief but helpful for flagging anything that needs follow-up. It's not a substitute for a GP conversation about treatment, but it gives you the data to have that conversation.

How Often to Test

First panel: get a full panel as your baseline. This is your reference point for everything that follows.

Six months later: retest the markers you're actively trying to change. If you've been supplementing vitamin D, check your level. If you changed your diet for metabolic health, recheck HbA1c and fasting insulin.

Annually: full hormone panel plus metabolic markers. This catches drift before it becomes a problem.

If symptoms change: don't wait for your annual panel. If your energy, libido, mood, or performance changes significantly, test first and guess second.

What to Do With the Results

If your total testosterone comes back below 15 nmol/L with symptoms, that's a conversation worth having with either your GP or a private men's health clinic. The NHS vs private TRT route is covered in detail here, understanding both options before your appointment will make that conversation more productive.

If your metabolic markers are heading in the wrong direction, that's a lifestyle intervention before it's a medical one. Resistance training, sleep quality, and dietary changes can move HbA1c, fasting insulin, and triglycerides significantly within 12 weeks.

If your vitamin D is low, supplement. This is one of the easiest, cheapest interventions available and the evidence for its effects on testosterone, mood, and immunity is substantial.

The data is only useful if you act on it. Get the panel, review the numbers against the optimal ranges above, and prioritise the interventions with the largest expected returns first.

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