The pill

The pill (combined pill or birth control pill) is a tablet that contains a combination of two hormones, an oestrogen and a progestin. These hormones primarily prevent ovulation.

The pill usually needs to be taken at the same time every day for three weeks and then the patient has a week’s break. The week’s break is replaced by the woman taking 7 inactive tablets with some pills. A woman normally starts her period during or just after the pill free break/use of the inactive tablets. The pill becomes effective as a contraceptive after seven days of taking the pill on a daily basis.

Common products

In general combined pills can be categorised by their dose of oestrogen in each pill, the type of progestin in each pill or the daily routine needed to take them.

• Low dose, standard dose and high dose pills ( containing 20mcg, 30-35mcg and 50mcg ethinylestradiol per pill respectively)
• Second and third generation progestin component pills (containing for example the progestins levonorgestrel and gestodene respectively)
• Standard, ‘everyday’ (ED) and tricyclic pills (respectively 21 day course plus 7 day break, 21 days active pills plus 7 days inactive pills, and 21 day pills with each week containing a set of pills with different amounts of hormone in them)
• For information on the “mini-pill”, please click here.

How effective is the pill at preventing a pregnancy?

The combined pill is very effective at preventing pregnancy as long as it is taken as instructed.

With ‘perfect’ use the combined pill is 99% effective but this effectiveness falls to 92% when typical, ‘real-world’ use is considered.

What are other good things about the pill?

Combined pills are also generally safe and suitable for most women, although they carry more risk than mini pills.

The reasons why a woman might not be suitable for the combined pill are summarised in WHO Medical Eligibility Criteria (MEC).

In general key contraindications are pre-existing conditions that predispose to deep vein thrombosis, conditions that increase the risk of cardiovascular complications, situations affecting how the pill works or is metabolised (such as TB or HIV drug interactions or liver disease), or special situations like breast feeding.

Combined pills generally make periods lighter, and reduce period pain. They also have non-contraceptive benefits such as reducing the risk of ovarian and endometrial cancer.

What women say they like about the pill

According to the WHO, some women prefer the pill because: its use can be controlled by the woman; it can be stopped any time without the provider’s help; and it does not interfere with sex. Many women also like that the pill allows them to have a regular period, which feels more natural and helps allay fears about any negative effect on their fertility.

What aspects of the pill might women not like/ should they be aware of?

The pill can cause side effects.

Common side effects include changes in bleeding pattern, from irregular bleeding to complete absence, headaches, dizziness, nausea and breast tenderness.

Women also may avoid the pill if they feel their routine is not regular enough to help them remember to take pills on time.

Crucial to a patient using the pill correctly is to ensure that pills are taken as instructed particularly around the ‘pill-free’ interval, meaning the time between finishing one pack and starting another. The risk of pregnancy related to missing/forgetting pills during the cycle should also be carefully explained during counselling.

Unlike condoms, pills do not protect against sexually transmitted infections.