What blood test checks your testosterone?

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

Here's what a proper testosterone panel includes. Total testosterone is the headline number, but on its own it can mislead. Free testosterone (or bioavailable testosterone) tells you how much is actually usable, and SHBG explains why — it's the protein that binds testosterone and controls availability. Useful extras are LH and FSH (the brain signals that tell your testes to produce testosterone, which help pinpoint where a problem sits), plus oestradiol, and often a wider screen: thyroid, vitamin D, and HbA1c, since all of these affect your hormones.

Timing matters as much as the panel. Testosterone peaks in the early morning, so the sample should be taken before 10am, ideally fasted — and a low result should be confirmed with a second morning test before drawing conclusions. One number on its own isn't a diagnosis.

What to do: ask your GP for a morning testosterone test that includes free testosterone and SHBG, not total alone. If you'd rather not wait, reputable at-home finger-prick kits measure the same markers and post you the results — a convenient starting point, but confirm anything abnormal with your doctor. Then read every number next to how you actually feel.