The results come back and the GP says everything looks fine. You feel like shit, your energy is off, you’ve put on ten pounds without changing much, and your drive — professional, sexual, general forward momentum — has quietly dropped. But the numbers are normal. That’s where the conversation ends.
The standard GP panel was designed around one question: is this man about to have a medical event? It measures total cholesterol, basic glucose, maybe TSH if you push, and a handful of markers that catch serious deficiency or acute disease. It’s a floor inspection, not a structural assessment.
For a man in his late 30s or early 40s, the clinical floor is a long way below where you actually want to be. The difference between “not diabetic yet” and “metabolically healthy” is years of trajectory. The difference between “testosterone in range” and “enough free testosterone to actually function” is whether a protein called SHBG is rendering most of what you produce biologically useless. The standard panel doesn’t pick up these distinctions because it wasn’t built to.
It’s a floor inspection, not a structural assessment.
The floor, not the ceiling
The concept worth keeping here is this: normal is the floor, not the ceiling. Reference ranges are set to catch the bottom 2.5% — the threshold below which something is clearly wrong. They don’t represent optimal function. A total testosterone of 12 nmol/L is “in range” at most labs; a reading of 22 nmol/L is also “in range.” These are not the same situation. Knowing you cleared the floor tells you almost nothing about where you actually stand.
ApoB, not total cholesterol
Total cholesterol is close to useless as a standalone risk marker. ApoB — apolipoprotein B — measures the number of lipoprotein particles that can enter arterial walls and form plaque. Each LDL particle carries one ApoB molecule, so ApoB is a direct count of the atherogenic particles in circulation, regardless of how much cholesterol sits inside each one. You can have average total cholesterol and a high ApoB. You can have elevated total cholesterol and a low ApoB. The number your GP fixates on may be the less meaningful one.
Optimal ApoB for a man with no other risk factors is generally cited below 80 mg/dL. Most lab reference ranges flag anything under 100–130 mg/dL as acceptable. That gap matters over decades. If yours comes back above 80, ask your GP what the absolute risk reduction is from any proposed treatment — not the relative risk figure, which inflates the apparent benefit — and ask specifically how many people need to receive the treatment before one cardiovascular event is prevented. Those are different questions from “should I take this.” They’re the questions that let you decide.
The number your GP fixates on may be the less meaningful one.
Fasting insulin and HbA1c
HbA1c measures average blood glucose over three months and will flag type 2 diabetes at 6.5% or higher. Prediabetes is technically flagged above 5.7%. A reading of 5.6% will be reported as normal. What it won’t tell you is whether your fasting insulin has been working hard for years to maintain that clean glucose — a condition called insulin resistance that can precede any HbA1c change by a decade.
Fasting insulin gives you the other half of the picture. A reading above 10 μIU/mL while fasting is worth taking seriously, even if your glucose looks clean. Optimal is generally considered below 7 μIU/mL. A reading of 14 μIU/mL with normal glucose means your system is working overtime to hold the line. That’s an early warning the standard panel misses entirely.
Testosterone: test the whole picture
A total testosterone reading alone is the bloodwork equivalent of checking how much money is in your bank account without knowing your mortgage. Sex hormone-binding globulin (SHBG) binds to testosterone and renders it biologically inert. High SHBG with decent total testosterone can produce worse functional outcomes than moderate total testosterone with low SHBG. What matters is how much is actually available to your cells, not how much is circulating in a bound and unusable form.
Request a full hormone panel: total testosterone, free testosterone, SHBG, and LH/FSH. Morning draw only — testosterone peaks in the early hours and can read 15–20% lower by midday. Book it for 8–9am and keep that time slot on every retest, or you’re not comparing like with like. When the results come back, look at where your free testosterone falls within the reference range for your age — upper half is the target, not simply inside the range. If your SHBG is running above 50 nmol/L with borderline total testosterone, the binding protein is likely the actual problem, not your production.
That’s an early warning the standard panel misses entirely.
Thyroid: don’t stop at TSH
TSH measures your pituitary’s signal to the thyroid — it’s upstream of the problem in many cases. A TSH of 2.5 can look unremarkable while free T3, the active form of thyroid hormone, runs below its useful range, producing exactly the symptoms you’d expect: slow metabolism, difficulty losing weight, poor energy despite adequate sleep. Optimal TSH for function is generally cited as 1.0–2.0 mIU/L. Ask for free T3 and free T4 alongside TSH, and if your TSH is above 2.5, the full picture becomes more important than the single number alone.
Vitamin D: this one is straightforward
Most men are deficient without knowing it. Vitamin D functions as a hormone with receptors in nearly every tissue — immune function, testosterone production, mood regulation, and cardiovascular health all have a documented relationship with it. Lab reference ranges typically flag deficiency below 20 ng/mL. Optimal function is generally 50–80 ng/mL.
Test your 25-hydroxyvitamin D level and start supplementing at 2,000 IU daily as a baseline. For every 1 ng/mL you need to raise your level, increase daily intake by roughly 100 IU. If you come back at 28 ng/mL and want to reach 55 ng/mL, that’s an additional 2,700 IU per day on top of the baseline. Retest in three to four months. This is one of the most consistently modifiable markers on this list, and the cost of testing and correcting is low.
What this won’t fix
A GP who works within NHS or insurance-gated protocols may decline most of these requests — ApoB, fasting insulin, and a full hormone panel are not standard referrals in many systems. Private labs run these panels without a referral for £150–300 total in the UK; comparable services exist elsewhere. That’s a real cost and not everyone can absorb it. Advocating more explicitly — bringing the test names in writing, asking for the clinical rationale for declining rather than accepting a vague refusal — works with some GPs and not others. Know which situation you’re in before expecting the system to deliver it.
This is one of the most consistently modifiable markers on this list, and the cost of testing and correcting is low.
Tomorrow morning, before anything else, write down the four markers your last blood test didn’t include: ApoB, fasting insulin, free testosterone, and 25-hydroxyvitamin D. Email your GP with those names and ask what the referral process is. That’s the starting move.
