The effects of the contraceptive pill

Effets de la pilule

In 1967, the Neuwirth law authorized the use of medical contraception in France. The pill becomes available to women on prescription from a doctor. Today, it is the most used contraceptive method in France 1 . Taken in strict compliance with the recommendations for use, it is an effective means of preventing pregnancy and treating certain symptoms, linked in particular to hormonal imbalances . However, taking the pill is not necessarily the best option for everyone. Side effects may occur, with more or less significant consequences on health . But what are the different effects of the pill? ? Let's see together how this small tablet, ingested daily by nearly 40% of French women using a means of contraception 1 , acts on the female body and psyche .

The effects of the pill: from the desired contraceptive effect to vascular risk

The primary purpose of the pill is “contraceptive” or “anticonception”, that is, it aims to prevent the conception of a child. This main desired effect, called “therapeutic”, is the one for which it was initially designed and marketed.

As with any medication, in addition to this primary effect there are so-called “side” effects. These do not appear systematically in all treated patients. They depend on many factors: the clinical profile of each individual, the type of product administered, interactions with other treatments, etc. Some provide a benefit and are therefore desired: the pill is often prescribed to alleviate menstrual pain or reduce acne. Conversely, others are negative, ranging from simple inconvenience to serious risk; they are then qualified as undesirable. The pill can cause spotting , reduced libido, migraines or even increase the risk of a stroke.

Let’s detail these different benefits and risks associated with the pill.

The desired effects of the pill

The therapeutic effect of the pill: preventing pregnancy

First of all, what is the pill ? It is an oral hormonal contraceptive used to prevent unwanted pregnancy. It allows women of childbearing age, non-menopausal, non-sterile and not wishing to have children, to avoid becoming pregnant following sexual intercourse with a male partner. It comes in the form of tablets, composed of female sex hormones, to be swallowed every day at a regular time. But how exactly does the pill work ?

The pill acts on the female body by modifying the hormonal cycle. It contains synthetic hormones, which resemble those naturally produced by the ovaries : estrogens and progesterone. Regardless of the type of pill , the continuous intake of these estrogen or progestin hormones blocks one or more key steps in the reproductive process. Thus, the pill acts in such a way as to:

  • suppress ovulation, that is to say the release of the egg from the ovary, by stopping the secretion of the two hormones responsible for it (FSH, follicle-stimulating hormone, and LH, luteinizing hormone ) ;
  • prevent fertilization, by causing the thickening of cervical mucus (a substance secreted at the cervix), thus hindering the progression of sperm from the vagina to the uterus and the fallopian tubes;
  • obstruct implantation, by inhibiting the development of the uterine mucosa, making it thinner and therefore unsuitable for the implantation of an embryo 2 .

Side effects of the pill providing benefit

In addition to this contraceptive effect, the pill can have advantageous side effects and become an ally in the management of certain disorders and illnesses. Thus, it is used to:

  • regularize the menstrual cycle;
  • reduce menstrual bleeding, in volume and duration, in the event of heavy periods ;
  • cause an absence of periods ( amenorrhea ), whether constantly, to relieve the symptoms of endometriosis for example, or occasionally, to participate in a sporting competition or manage your periods on vacation ;
  • reduce menstrual pain;
  • treat certain symptoms of premenstrual syndrome (PMS) or polycystic ovary syndrome (PCOS);
  • minimize the risks of developing certain cancers, such as ovarian cancer, uterine cancer or colon cancer;
  • reduce acne.

Side effects of the pill

In some cases, taking the pill has annoying and even harmful repercussions on the body. These side effects, if known, are listed in the medication leaflet.

Adverse effects of the pill without serious and imminent danger

Among the unpleasant consequences reported more or less frequently but a priori without danger 2-3 (unless worrying persistence, worsening or accumulation with other symptoms), we can cite:

  • bleeding outside the period and during the pack, grouped under the name of spotting ;
  • headaches ;
  • nausea and vomiting;
  • abdominal cramps;
  • tension or pain in the breasts;
  • water retention;
  • a change in appetite and therefore weight variations;
  • acne problems;
  • a decrease in libido ;
  • vaginal dryness or yeast infections;
  • an increase in hair growth;
  • mood disorders.

In general, these phenomena are temporary; they appear during the first months of treatment and eventually disappear over time. You should not hesitate to report them to your doctor, and to change your pill or method of contraception if these effects cause significant and lasting discomfort.

Serious side effects of the pill

These are mainly vascular problems. Indeed, taking a combined pill (containing both estrogen and progestin) exposes you to a greater risk of blood clots than in the absence of hormonal contraception. And this risk is higher with 3rd and 4th generation combined pills than with those of 1st and 2nd generation .

The development of such a clot in a vein or artery is called a thrombosis, venous or arterial. The consequences can be very serious:

  • phlebitis, if the clot ends up blocking a deep vein, generally in the legs;
  • a pulmonary embolism, when the clot breaks away, migrates into the bloodstream and ends up blocking the pulmonary artery;
  • a heart attack ;
  • a cerebral vascular accident.

We are talking about an increased risk of venous and arterial thromboembolism, favored by other aggravating factors. The combined pill is therefore contraindicated in women:

  • already victims of a vascular accident;
  • presenting hereditary predispositions to thrombosis;
  • with diabetes;
  • suffering from hypertension;
  • having cholesterol;
  • victims of intense migraines called “with aura”;
  • having, having had or likely to have breast or uterine cancer;
  • smokers;
  • etc. 2-3

Taking the pill is therefore not anecdotal. Choosing this method of contraception must be done with full knowledge of the facts. To do this, it is imperative to consult a health professional, gynecologist or midwife, capable of explaining the different implications and assessing the risks linked to the profile of each. In the event of a contraindication, there are many other methods of contraception to turn to.

And you, are you taking the pill? Are you suffering from any of its side effects? To help you manage your cycles, Perdième brings you a note of (re)comfort and softness with its effective, pretty and colorful menstrual underwear .

Written by cd


  1. French women and contraception: first data from the 2016 Health Barometer . Public health France.
  2. Oral contraception or “pill” . VIDAL.
  3. Oral contraceptives . (2022, June 3). Ministry of Health and Prevention.