Contraception – Mini-Pills

The mini-pill has been around in this country for over a decade. The name is slightly misleading; it is not a very low dosage of an ordinary combined contraceptive pill, as many people think. The mini-pill contains only progestogen, rather than progestogen and oestrogen; hence its other name of progestogen-only pill (Pop). Even its dosage of progestogen is smaller than is usually found in combined pills.

Because the mini-pill contains no oestrogen, it is considered much safer than the combined pill for women at risk from the oestrogen-related side-effects especially those involving the cardiovascular system. It is also considered safer for women over thirty-five, and those with a history of bad headaches or high blood pressure.

How it works

The progestogen in the mini-pill has little effect on ovulation in some women. About forty per cent of those taking the mini-pill will still experience normal ovulation and periods. Twenty per cent more will vary between ovulatory and anovulatory cycles — those with and without an egg. The other forty per cent will rarely or never experience ovulation. In some women the dose of progestogen does suppress ovulation completely; in these cases the woman will not have any monthly bleeding. One of the main effects of the mini-pill is to make the cervical mucus thick and virtually impenetrable to sperm. It also acts on the lining of the uterus so that if an egg is fertilized it will not be able to implant.

Taking the pill

The mini-pill is taken every day, including during periods. It is important that this pill is taken at the same time every day, as its margin for error is much smaller than that of the combined pill. The ideal time to take it is in the early evening, at about six or seven p.m. This is because the pill exerts its maximum effect on the cervical mucus about four hours after it is taken. Since most couples generally make love late at night when they go to bed, this ensures that the maximum contraceptive effect occurs more or less at the same time as intercourse. This doesn’t mean that you will get pregnant if you make love in the morning or at lunchtime, but it is best as a general rule. The worst time to take the mini-pill is last thing at night, as if you make love then you will be relying on the tail-end of the effect of the previous night’s pill.

Because the dosage is so low, if you forget to take your pill within three hours of the normal time (or if your system is interrupted by vomiting or diarrhoea), you should continue to take the pills but use a back-up method of contraception for the next 14 days. Some doctors feel that this is over-cautious, and that 7 days would be enough, but until this is officially approved it is best to play safe.

When you start to use the mini-pill, you begin with the first pill on day 1 of your normal cycle — the first day of your period. From then on you take a pill every day for as long as you wish to use this method. For the first 14 days (again, some doctors say 7), while the hormone level builds up, you will need to use an alternative form of contraception. After that time you should be protected from conception all the time including during periods.

It is possible to start the mini-pill on the day of a miscarriage or abortion, again with 7 or 14 days of extra protection. After childbirth you can start the mini-pill on around day 7, and the contraceptive effect will be immediate. If you are breastfeeding, you can delay starting the pill until the fourth week. Incidentally, the mini-pill can be used during breastfeeding. Unlike the combined pill it has no effect on the quantity of the milk and very little on the quality. For all women taking the mini-pill, regularity and conscientiousness in pill-taking is very important. As Guillebaud says, ‘this pill is not for the forgetful’.


The most common side-effects of the mini-pill relate to the woman’s periods. They may become irregular or shorter, disappear altogether, or spotting may occur between periods. If your periods disappear altogether, it probably means that you are very well-protected against pregnancy, as this implies that you are not ovulating. Of course it could also mean that you are pregnant, especially if this sign occurs suddenly after more normal periods on the mini-pill. Mini-pill users are generally told to expect irregularities in their periods — they may be as infrequent as one or two a year. Dysmenorrhoea (painful periods) can be reduced in some users, though not as much as in women who use the combined pill.

Other side-effects can include headache, raised blood pressure, hirsutism, dizziness, weight gain, liver problems, loss of libido, and breast tenderness. Again, these are less common than among combined-pill users. Unlike the ordinary pill, the mini-pill appears to increase the incidence of ovarian cysts. Contraindications against use of the mini-pill tend to be the same as against the combined pill. Once again, doctors are probably being over-cautious, and some are more easy-going over these rules. Abnormal genital bleeding becomes a more important contraindication against the mini-pill than the combined pill, as the mini-pill itself can produce irregular bleeding. Also a past history of ectopic pregnancy militates against the use of the mini-pill, as pregnancies resulting from this pill failing are more likely than usual to be ectopic.

Diabetes (known or suspected) and acute mononucleosis (glandular fever) can also be contraindications. The danger signs -for women on the mini-pill are the same as those for the combined pill. The mini-pill does not have to be stopped before surgery or if the woman is immobilized, as it contains no oestrogen which is the danger factor in these cases.


The failure rate of the mini-pill is somewhat higher than that of the combined pill, and varies between 0.5 and 4 per 100 woman/years. The lowest failure rate occurs among women who are thirty-five to forty, whose fertility level has declined already. Because the pill dosages are so low, missing one pill can quite easily lead to pregnancy. It is thought that fertility is re-established virtually immediately the mini-pill is stopped, although for those women who have actually stopped ovulating it may take a little time.


The mini-pill has many of the benefits of the combined pill (discreetness, portability, ease of use) without many of the combined pill’s associated health risks. However, the minipill is slightly less reliable than the combined pill, and does carry an increased risk of ectopic pregnancy. The mini-pill is subject to the same ethical criteria on hormonal contraceptives as the combined pill, except that its method of working is different. Couples thinking about using the mini-pill instead of the less safe combined pill should think very carefully; they may be swopping greater risk to the woman for the risk of causing occasional early abortions. To maximize the actual contraceptive effect of the mini-pill, the woman should take it regularly in the early evening.