How birth control pills work

To avoid unwanted pregnancies the birth control pill is a highly effective system. What are its components and the mechanisms by which it acts? Here are the answers to the most common doubts.

Known and used successfully for a long time, the birth control pill now offers different formulations and dosages. Every woman, with the advice of the gynecologist, can find the most suitable solution for her characteristics and her age.

Let’s see what are the possibilities of choice and the mechanisms that allow the pill to avoid unwanted pregnancies.

Different types of pill

The estroprogestin pill contains a combination of two female hormones (steroids): an estrogen and a progestin. The type of associated molecules and the ratio of hormone amounts characterizes the different pills.

There is the monophasic pill, that is, fixed dosage: each pill contains the same amount of steroids. The biphasic pill has a dosage in two phases: estrogen is fixed and progestogen is taken in two different dosages, with a release that therefore varies according to the period of the cycle.

In the triphasic pill hormones are associated in three different dosages. The latter pill contains a very low total dose of hormones that approaches the body’s production of estrogen and progesterone. The so-called four-phase contains estradiol and a progestogen combined in four different dosages.

The packs of the different types of estroprogestin pills on the market can contain 21 or 28 tablets: in the first case, a break of one week must be made between one pack and the next, during which the pseudomenstrual flow will appear. In the second instead there will be 24 or 26 pills that contain hormones, while in the remaining (respectively 4 or 2) there will be no active ingredient (placebo pills). In this case the pseudomenstrual flow usually manifests itself while taking the last tablets.

Then there is also the pill consisting solely of progestogen hormone (progestogen pill). There are low-dose formulations that should be taken every day even during the menstrual flow. Other formulations with a higher level of hormones have contraceptive safety similar to the estroprogestin pill.

Different mechanisms of action

The estroprogestin pill inhibits ovulation by blocking the synthesis of two hormones: FSH and LH, called gonadotropins and produced by the pituitary, a small gland located at the base of the brain.

The pill also causes a thickening of the cervical mucus and a thinning of the endometrium, the mucous membrane of the uterus, which thus becomes less suitable for the possible implantation of an egg.

Contraception with the pill involves taking a dragee a day, possibly always at the same time (or, in case of forgetfulness, with a delay that varies at most between 12 and 24 hours depending on the type of pill) starting from the first day of menstrual flow, continuing for 21 days. (or 24 or 26 days). This is followed by a seven-day break (or 4 days or 2 days), during which you have pseudomenstrual flow. At that point you start again with a new pack of tablets.

The estroprogestin pill, in addition to ensuring a very high contraceptive efficacy, has numerous beneficial non-contraceptive effects. Current hormonal dosages have dramatically decreased the side effects that were seen in the past.

It is suitable for all healthy women of childbearing age, from the youngest to the oldest, although it is always essential to seek advice from your doctor before taking it. For adolescents, the pill is considered the best contraceptive method, both for its effectiveness and for the numerous benefits that are added to the contraceptive effect.

For example, the pill attenuates premenstrual syndrome, improves cycle irregularities typical of adolescence, counteracts the onset of acne and seborrhea.

However, there are also cases in which the pill is not indicated, for example in women who smoke heavily or in those with a high risk of cardiovascular disease. That is why before starting to take the pill it is essential to consult with your trusted gynecologist.

As far as the progestogen pill is concerned, the contraceptive activity is exercised through a double mechanism. The cervical mucus becomes very scarce and not very penetrable by the spermatozoa for the duration of the cycle and the ciliated epithelium of the tubes is altered. The most recent progestogen pills also have an inhibiting action on ovulation.

This type of pill is generally well tolerated. Its main side effect is cycle disorders: amenorrhea (lack of menstruation) and menstrual irregularities.

The pill with only progestogen has a contraceptive safety lower than the classic pill. It is indicated for women who cannot take estrogen. Also in this case it is up to the specialist to establish the most correct indication for each woman.

Contraceptive pill: precautions and side effects

It is important to remember, however, that birth control pills are still a drug and therefore, in all cases, their intake as a therapy or as a method to avoid pregnancy must be well thought out by every woman, and should always be started only on the prescription of your gynecologist, who must evaluate whether the benefits outweigh the risks.

The contraceptive pill, in fact, like any medical treatment or medicinal product, requires first of all accurate examinations and a thorough diagnosis, which every gynecologist should carry out on his patients before starting the administration of the pill. The goal is the prevention of the development of symptoms and the reduction of negative disorders for the well-being, health and overall quality of life of the woman.

In fact, although its use is widespread among women in many countries of the world, the pill is not without risks and contraindications. The results of medical studies and research by the scientific community have highlighted how in some cases the pill can be the cause or contributory cause of weight gain, blood loss outside the menstrual cycle (phenomenon called spotting), lack of menstruation, abundant cycles, increased pressure, nausea, depression, mood swings or irritability, decreased libido, abdominal pain, headache and other complications involving fertility and women’s health in general.

Women with a lifestyle or a non-optimal health condition (such as smoking), but not only, are exposed to these risks. It is, in fact, an artificial alteration of the natural hormonal cycle of one’s body, which could suffer unwanted effects. The gynaecologist can prescribe a treatment plan also considering adopting a pill with a different formulation or alternative therapies, such as the patch, the IUD or the vaginal ring, respecting the specific needs of each patient.

For this reason, you should not limit yourself to undergoing a thorough check before starting to take the pill, but you should always be careful during the period of taking it, keeping in touch with your gynecologist and proceeding to a suspension of therapy if it is not the contraceptive suitable for you.

In addition, it should be remembered that all forms of hormonal contraception (or, in general, oral contraception) do not give any protection against risk factors related to sexually transmitted diseases, unlike other contraceptive methods. The feeling of protection, on the contrary, could suggest that there is also a link with the prevention of diseases: to avoid an increase in the risk of diseases, it is necessary that girls and women receive information that allows them to protect themselves.