The ovaries form part of the female reproductive system. The ovaries are oval-shaped and around four centimetres long (roughly the size of an almond). The two ovaries sit either side of the uterus, supported by ligaments and the blood supply which comes from the side of the pelvis. The fallopian tubes run along the side of the ovaries into the uterus.


Diagram of female reproductive system


Who has ovaries?

You may have ovaries if you are:

  • A woman who was assigned female at birth (recorded as female on her birth certificate).
  • A transgender man or non-binary person who was assigned female at birth.
  • An intersex person.
  • A man who has a difference in sex development (DSD).

If you have previously had surgery on your reproductive system, such as a hysterectomy (removal of the womb), you may have had your ovaries removed (oophorectomy).

If you are not sure whether you have ovaries, it is best to speak to your GP.


What do the ovaries do?

The ovaries have two main functions:

1. They produce ova (eggs)

During a process called ovulation, which occurs midway through a normal menstrual cycle, the ovaries release an egg, which can then be fertilised by sperm in order to create an embryo. If this embryo then implants into the lining of uterus (womb), it may grow into a foetus.

Usually, only one egg is released each menstrual cycle. Sometimes however, the ovaries can release two eggs in one menstrual cycle (this can lead to the birth of non-identical twins if both eggs are fertilised).

Ovaries contain all the eggs that they will ever have at birth. More eggs will not be produced during a lifetime.

Ovaries release an egg (ovulate) once a month from puberty (the period during which people reach sexual maturity, usually during their teenage years) to the menopause (the time during which a person stops menstruating, i.e. having a period).

Some types of contraception can stop the ovulation process from happening, in order to prevent pregnancy. You will also not ovulate if you are pregnant.

2. They produce female sex hormones oestrogen and progesterone

These two hormones play an important role in the menstrual cycle.

Oestrogen production will be higher in the first half of the menstrual cycle, before the egg is released. When oestrogen levels are high, this causes a surge in a luteinizing hormone, which triggers the release of the egg from the ovary.

Oestrogen also helps regulate cholesterol, keep your bones healthy and can affect skin and other tissues including the vagina. It helps with vaginal blood flow, lubrication and keeps vaginal tissue elastic.

Progesterone production will be higher in the second half of the menstrual cycle, after the egg has been released. Progesterone causes the lining of the uterus (womb) to thicken, ready for the egg to implant if it has been fertilised.

Oestrogen and progesterone levels fall after menopause.

Hormone replacement therapy (HRT) uses both these hormones, unless you have had a hysterectomy, when oestrogen only HRT is usually used.


Ovarian health

Ovarian cysts are very common before the menopause. You can find out more about ovarian cysts here.

Some people have a condition call Polycystic Ovary Syndrome (PCOS). Again this is very common; it is estimated that 1 in 10 women have PCOS. You can find out more about this here.

Ovarian cancer is an uncommon cancer, which affects 1 in 50 women according to Cancer Research UK. There are many different types of ovarian cancer. You can find out more about ovarian cancer and its symptoms here.


How Ovacome can help

If you have any questions about the ovaries, or are worried about symptoms that you are experiencing, please get in touch on our support line. You can call us on 0800 008 7054 or email [email protected] . You can also use the pink instant chat box at the bottom of your screen to ask us a question. We are open Monday to Friday, 10am to 5pm. A member of our team will be able to offer you personalised information and support.

If you are experiencing any unusual symptoms, which are persistent, please don’t delay going to see your GP.


Last updated December 2021. Due for review December 2023.