Testosterone is a sex hormone produced by the testes in men. Women also produce testosterone in their ovaries and adrenal glands, but usually in smaller quantities. Testosterone governs many essential body functions, such as sex drive (libido), energy levels, healthy bones, muscle mass, strength, and mood. It also controls sperm production, so changes in this hormone can affect fertility. Stress levels, how much alcohol you drink, and the amount of exercise you do can all affect the amount of testosterone your body makes. Low testosterone levels can sometimes cause unwanted symptoms, such as low sex drive and low mood. Both men and women may experience a natural decrease in their testosterone levels with age. Measuring your testosterone level is easy with our simple testosterone finger-prick blood test kit, which you can do at home or in a clinic. With our UK Testosterone Blood Test, you’ll get expert advice and follow-up on steps to take if your testosterone level is outside the normal range. Please take your sample before 10am. If you use hormone gels, pessaries, patches, or tablets, we strongly recommend a venous sample to minimise contamination. Hormones can be absorbed deep within the skin even after minimal contact and remain there for weeks despite vigorous handwashing. Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed.