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 and reduce acne and excess hair growth. 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) and cholesterol levels (triglycerides). Low dose preparations appear to be better (e.g. 20µg oestrogen pills). However, other evidence shows no negative effects of the oral contraceptive pill on risk factors for type 2 diabetes and cardiovascular diseaseIt is not currently known what the overall combined effect of hormonal contraception on long-term health in PCOS is. The oral contraceptive pill cannot 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 and reducing androgen excess, but has similar effects on hair growth. Metformin also has a more positive effect on risk factors for cardiovascular disease and type 2 diabetes such as cholesterol levels and insulin than the oral contraceptive pill.

Content updated 25 August 2011