Hormonal contraception (oral contraceptive pills, hormonal implants)

The oral contraceptive pill (‘the Pill’) is commonly prescribed for women with PCOS. The Pill can regulate menstrual periods and reduce menstrual cramps. There are a wide range of oral contraceptive pills with differing doses of oestrogen and progesterone.

Other hormonal contraception devices prescribed for women with PCOS include hormonal implants, vaginal contraceptive rings and intra-uterine devices containing progesterone.

How does hormonal contraception work?

The oestrogen and progesterone in hormonal contraception act to override the body’s normal hormonal control of the menstrual cycle and ovulation. The body increases production of sex hormone binding globulin (SHBG) which is a protein that binds to male hormones (testosterone) in the blood. This reduces the activity of testosterone and reduces the symptoms of male hormone or androgen excess.

Through allowing the regular shedding of the uterus lining or endometrium during menstruation, the Pill can reduce the risk of developing endometrial cancer.

Possible side effects

Some of the more common side effects associated with hormonal contraceptive devices include:

• Mood changes
• Weight gain or weight loss
• Bloating
• Breast tenderness  
• Irregular bleeding can occur

These side effects can also differ depending on the oestrogen and progesterone content of the pill/device. 

Potential risks

There is some recent evidence that hormonal contraception may increase insulin resistance and abnormal glucose tolerance (a sign of early diabetes). Low dose preparations appear to be better (e.g. 20mcg oestrogen pills)

It is not currently known what the overall combined effect of hormonal contraception on long-term health in PCOS is.

The oral contraceptive pill can not be used if you have high blood pressure, are a smoker, or have had a deep vein thrombosis (DVT) in the past.

Other medications

Insulin-sensitising drugs (primarily metformin) improve menstrual regularity and ovulation. Metformin does not appear to be quite as effective as the oral contraceptive pill in improving menstrual regularity, but has similar effects on hair growth and also reduces insulin resistance, and likely decreases the risk of diabetes.

Content updated July 31, 2009