Sex Hormone Binding Globulin Test

What is Sex Hormone Binding Globulin?

Sex Hormone Binding Globulin (SHBG) is a protein found in the blood. It is mostly made in the liver but a small amount is produced in the testes and other organs. SHBG attaches to the sex hormones dihydrotestosterone (DHT), testosterone, and oestrogen, which are necessary for the physical characteristics, sexual behaviour, and development of the reproductive system in males and females. Once attached, SHBG transports these hormones around the body. The role of SHBG is to regulate the levels of sex hormones working in the body. By attaching to the sex hormones, SHBG stops the tissues from using them. The tissues can use these sex hormones only when they are not attached to SHBG (i.e., they are 'free' in the blood).

Can I buy a Sex Hormone Binding Globulin online?

Please click on the button below to buy a test. The kit includes a reply-paid envelope to our laboratory.

Results are within 24 hours and include an interpretation from a doctor.

What is a Sex Hormone Binding Globulin test?

The SHBG test measures the amount of SHBG in a blood sample. A SHBG test shows how much testosterone is unattached ('free') in the blood. Often this test is done along with other tests measuring testosterone, such as the total testosterone test that determines both the amounts of testosterone attached and unattached to SHBG. We also offer a Free Testosterone test and a Total Testosterone Test

Why is a Sex Hormone Binding Globulin test important?

Testosterone is an androgen and is generally known as the major sex hormone in males; females also have testosterone albeit at lower levels than in males. DHT is made from testosterone. SHBG is important because, after puberty, testosterone in adult males is responsible for libido (sex drive), muscle mass, and in sperm production. Testosterone is important in adult females for healthy working ovaries, bone strength, and brain functioning. Abnormal testosterone levels can therefore cause sexual and reproductive problems.

In males and females, the SHBG test can be used to diagnose hypogonadism, a condition whereby the gonads (ovaries or testes) produce less than normal levels of sex hormones, as well as sperm or eggs. It can also be used to find out why these hormones are too low or too high. The SHBG test can help determine if the body's testosterone is working normally in males who have symptoms suggesting too little testosterone and in females who have symptoms suggesting too much testosterone.

Who should have their Sex Hormone Binding Globulin level tested?

The SHBG test is ordered if you have signs and symptoms suggesting an abnormal testosterone level. In males, signs and symptoms of low testosterone levels include a low libido, and problems getting an erection (erectile dysfunction) and fertility issues. In females, signs and symptoms of high testosterone levels include a deepening voice, excessive hair growth on the face and body, weight gain, acne, menstrual periods that are irregular or missed, and fertility issues.

How to test for Sex Hormone Binding Globulin?

A small blood sample is necessary for a SHBG test. The blood sample is easily collected by yourself using a test kit, which contains full instructions and is provided by your doctor. The blood sample is taken from the tip of your little finger. The blood drops are then collected in a collection tube until it fills the tube up to the top marked line. If blood drops stop, then the rest of the blood is collected from the other little finger tip. Once the cap on the collection tube is on, it is gently turned upside down several times before labelling. All that's left to do is put it in the packing wallet and post. The SHBG test results will be sent to your doctor at The Online Clinic who will explain to you what they mean, and determine whether you need to have more tests.

What are normal Sex Hormone Binding Globulin test results?

Low SHBG levels means that more testosterone is unattached to SHBG, and thus available for use by the body (i.e., it is 'free' testosterone). As a man gets older, the SHBG level usually increases and testosterone level falls. SHBG levels are usually higher in women during pregnancy.

Low SHBG levels may indicate obesity, type 2 diabetes, underactive thyroid, Cushing's disease (excess cortisol hormone production), acromegaly (excess growth hormone production), polycystic ovary syndrome (females), or your intake/dose of steroid treatment is too high, or you are overusing anabolic steroids (for exercise performance).

High SHBG levels means less testosterone is unattached to SHBG and available for use by the body. High SHBG levels may indicate an overactive thyroid, an eating disorder (underweight), liver disease, decreased sex hormone production (males), and a female is using oestrogen treatments (e.g., hormone replacement therapy, contraceptive pills).

How to maintain normal Sex Hormone Binding Globulin levels

A healthy lifestyle will support good body functioning, including your sexual and reproductive health. This includes regular physical activity (but not over-exercising), a well-balanced diet, maintaining a healthy body weight, limiting alcohol consumption, and avoiding smoking, sexually transmitted diseases, excess stress, recreational drugs, lack of sleep, and overheating the testicles (men).