Regulates how much free testosterone is available for the body to use.

Measures the active testosterone level. High levels may cause acne, hair growth, or hormone imbalance.

Regulates egg growth and menstrual cycle. High levels can suggest reduced fertility or menopause.

Triggers ovulation and supports hormone production. Used to check fertility or hormone imbalances.

The main form of oestrogen. Important for periods, fertility, and bone health.

Measures the total amount of testosterone in the blood, including both free and bound forms.

A hormone that helps regulate the menstrual cycle and supports pregnancy; levels rise after ovulation and during early pregnancy. Cycle day 21 progesterone can indicate whether ovulation is occurring in a particular cycle

Checks oestrogen levels in men. High levels can affect mood, fertility, or cause breast tissue growth.

Controls sperm production. Low or high levels may indicate fertility problems.

Stimulates the testes to make testosterone. Helps diagnose hormone issues or infertility.

A protein that controls how much oestrogen and testosterone is freely available in the body.

Shows how much active testosterone is available for use. Important for energy, mood, and sexual function.

Measures all testosterone in blood; important for mood, muscle, and libido.

Estimates active testosterone in women; useful for investigating acne, hair growth, or PCOS.

Estimates active testosterone in men; supports assessment of libido, muscle mass, and fertility.