Sex Hormone Binding Globulin (SHBG) LIS Code: SHBG
Private SHBG blood test £49. Shows how much testosterone is free to use and makes total testosterone results meaningful. No GP referral needed.
Before your test
Test Categories
About this test
Sex hormone-binding globulin (SHBG) is a protein made by the liver that carries testosterone and oestradiol in the blood. Hormone bound to SHBG isn't available to the body, so your SHBG level changes how much testosterone you can actually use, even when the total figure looks normal.
Why it's usually tested with testosterone
On its own, a total testosterone result can mislead. Someone with high SHBG can have a normal total testosterone but little free hormone, and the opposite is true when SHBG is low. Measuring SHBG alongside testosterone lets the laboratory work out your free testosterone, which is often the more useful number. If you're testing both, book a morning appointment, ideally before 11am, as testosterone is highest early in the day.
What can raise or lower SHBG
- Higher SHBG: getting older, an overactive thyroid, liver conditions, low body weight and medicines containing oestrogen, such as some contraceptives.
- Lower SHBG: carrying extra weight, insulin resistance and type 2 diabetes, polycystic ovary syndrome (PCOS), an underactive thyroid and the use of anabolic steroids.
Who books this test
- Men with symptoms of low testosterone whose total testosterone is borderline.
- Women being investigated for signs of excess male hormones, such as acne, thinning scalp hair or extra facial and body hair.
- Anyone whose doctor has asked for free testosterone to be calculated.
Most people get better value from our Testosterone Profile, which includes SHBG, testosterone, free testosterone and the pituitary hormones LH and FSH in a single blood draw. Results usually arrive within hours of the sample reaching the laboratory.
