SHBG blood test in Chiswick

What the test measures

Sex hormone binding globulin, or SHBG, is a protein made by the liver. It binds tightly to testosterone and, to a lesser extent, oestradiol, and carries them around the body. Hormone that is bound to SHBG is not readily available to tissues, so the amount of SHBG affects how much free, active hormone you have.

This is why two people with the same total testosterone can feel quite different. SHBG is usually measured alongside total testosterone so that free testosterone, or the free androgen index in women, can be calculated. On its own, SHBG also gives clues about liver, thyroid and metabolic health.

Your price includes the sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result and a GP feedback report on request. No GP referral is needed.

Who it is for

• You are a man with low libido, low energy or erectile difficulties and want a fuller hormone picture.
• Your total testosterone is borderline and your practitioner wants to estimate free testosterone.
• You are a woman with irregular periods, acne or excess hair growth and PCOS has been mentioned.
• You take testosterone, HRT or the contraceptive pill and want to understand your levels.
• Your practitioner is looking at insulin resistance or thyroid function as part of a wider review.

Understanding your result

A raised SHBG lowers the amount of free hormone and is seen with ageing in men, an overactive thyroid, liver conditions, low body weight and oestrogen-containing medicines. A low SHBG increases free hormone and is commonly linked with excess weight, insulin resistance, type 2 diabetes, an underactive thyroid and polycystic ovary syndrome. Neither is a diagnosis in itself; SHBG helps put your testosterone or oestradiol result into context.

Your report shows the laboratory reference range. A result outside it is a prompt for discussion with your practitioner, not a diagnosis.

Preparing for your test

No fasting is needed for SHBG itself. As it is usually read with testosterone, men should book a morning appointment, ideally before 11am, when testosterone is highest. Women with a regular cycle are often tested early in the cycle. Tell us about hormone treatments, thyroid medicines and the pill, and pause biotin supplements for two days beforehand.

SHBG is part of the Testosterone Check, which calculates free testosterone, and of the Hormone Health Check. You can also browse every blood test and price in Chiswick.

Questions

How much is an SHBG blood test in Chiswick?

An SHBG test costs £49. This includes your sample at our clinic, laboratory analysis, a practitioner review and a GP feedback report on request.

Why test SHBG with testosterone?

SHBG determines how much testosterone is free to act. Measuring both allows free testosterone to be estimated, which can explain symptoms that a total level alone does not.

What can lower SHBG?

Excess weight, insulin resistance, an underactive thyroid and some medicines can lower it. Changes to weight and metabolic health often shift SHBG over time.

Is a high SHBG a problem?

It can reduce free testosterone and contribute to symptoms, particularly in older men. Your practitioner will look for the reason and consider your free hormone levels.