What blood test checks your testosterone?

The core test is total testosterone from a morning blood sample, but to get the full picture you also want free testosterone, SHBG and a few supporting markers.

A proper panel measures more than the headline number, because total testosterone on its own can mislead. A thorough test includes:

• Total testosterone — the headline figure, but only a starting point
• Free testosterone — how much is actually usable by your tissues
• SHBG — the protein that binds testosterone and controls that availability
• LH and FSH — the brain signals to the testes, which tell you whether a low level starts in the testes or higher up in the pituitary
• Oestradiol, plus a wider screen of thyroid, vitamin D and HbA1c, since all of these shape your hormones

That LH and FSH pairing matters more than most men realise. If testosterone is low while LH and FSH are high, the testes are the issue; if all three are low, the signal from the brain is. The distinction changes what a doctor does next, which is why total alone is rarely enough. Timing matters just as much: testosterone peaks in the early morning, so the sample should be taken before 10am, ideally fasted and not during an acute illness, both of which can temporarily depress the result. A low figure should be confirmed with a second morning test, because one number on its own is never a diagnosis and only means something read next to your symptoms.

What to do: ask your GP for a morning testosterone test that includes free testosterone and SHBG, not total alone. If you would rather not wait, reputable at-home finger-prick kits measure the same markers and post you the results, which makes a convenient starting point, though anything abnormal should be confirmed with your doctor. Then read every number against how you actually feel, not in isolation.