Contraception: the pill

The birth control pill provides good protection against unwanted pregnancy and is easy to use. We provide information about the effects, advantages and disadvantages of the pill

The pill: the classic among contraceptives. There are many choices and medical advice is important

© Your Photo Today / All Medical

Reliable and easy to use as a method: it's no wonder that many women take birth control pills to protect themselves against unwanted pregnancy. But how does the pill actually work? To understand this, one must first know what a natural cycle is.

The natural cycle

The female sex hormones - estrogens and gestagens (progesterone) - regulate the menstrual cycle. In addition, they influence many other processes in the woman's body. The ovaries are the main place of production of the two hormones. The estrogens are created in the follicles. The egg cells also mature there. The corpus luteum that remains after ovulation then mainly produces the hormone progesterone.

Depending on the cycle, the ovaries are controlled by the hormones FSH (follicle-stimulating hormone) and LH (luteinizing hormone) from the pituitary gland. This in turn follows hormone signals from the brain (see graphic).

Monthly cycle of a woman

© W & B / Ulrike Möhle

In the first half of the cycle, FSH stimulates estrogen formation in women and the full maturation of the follicle (follicle, also ovarian follicle). In the middle of the cycle, a strong LH surge triggers ovulation. The egg moves into the fallopian tube, which moves it towards the uterus. The follicle becomes the corpus luteum. This now mainly produces the luteal hormone progesterone, but also estrogen. The hormone levels keep the control hormones FSH and LH low. There is usually no further ovulation.

Once the egg has been fertilized, the corpus luteum maintains the production of hormones until the placenta has taken over this task towards the end of the first trimester of pregnancy. Estrogen and progesterone increase increasingly during pregnancy.

If, on the other hand, fertilization has failed, the corpus luteum regresses and the hormone levels drop. The uterus sheds the mucous membrane (menstrual bleeding) and a new cycle begins.

This is how the pill works

The pill contains man-made sex hormones. They lead to largely constant hormone levels. Above all, pills that contain combinations of estrogens and progestins suppress the regulation by the higher-level control hormones. The egg does not ripen, in particular the LH rise does not occur.This means that there is usually no ovulation, i.e. no ovulation, any more. Accordingly, such pills are called ovulation inhibitors.

On the other hand, the progestins in the pill make the mucus on the cervix more impermeable to sperm. In principle, the sperm can no longer get into the uterus. In the event of ovulation, possible fertilization is also made more difficult by the fact that the fallopian tubes are quasi shut down and the egg cannot move forward. Ultimately, the lining of the uterus no longer builds up, so that a possibly fertilized egg has practically no chance of implanting.

Consultation with a doctor and examination

Before the gynecologist prescribes a contraceptive pill, he asks the woman about existing and previous illnesses and illnesses in the family. He examines the woman, also checks her blood pressure and weighs up the individual benefits as well as possible risks of the pill for her. He also explains the advantages and disadvantages of the drug to the woman. A known pregnancy precludes its use.

What types of pills are there?

There are numerous hormonal contraceptive products on the market. They differ in their composition and dosage. Today it is essentially low-dose combination pills with estrogen and progestin (micropills). There are also mini pills that only contain progestin.


Combination preparations made from estrogen and gestagen include single and multi-phase preparations. With single-phase preparations, all 21 coated tablets in one pack contain the same hormones in the same amount.

Multi-phase preparations consist of tablets with different amounts and compositions of hormones that are precisely matched to one another. The idea behind this is that this is close to the woman's natural cycle. It is imperative that these pills are taken in the correct order.

The estrogen in the micropill is usually the synthetic substance ethinylestradiol, a derivative of the natural estrogen estradiol. There are also preparations with estradiol. Different types of gestagen are possible for the progestogen content. A combination preparation always contains a certain type of estrogen and gestagen.

From the mini pill to the estrogen-free ovulation inhibitor

Mini pills only contain low-dose progestins. Therefore, otherwise possible estrogen side effects are eliminated. Preparations with levonorgestrel or desogestrel are currently available. Desogestrel is dosed comparatively higher here.

Levonorgestrel-containing minipills work mainly through the local effects of progestin - on the mucus plug, on the uterus and on the fallopian tubes - less by influencing the superordinate control hormones. The mini-pill containing desogestrel is different: it also inhibits ovulation. Corresponding mini pills are therefore called estrogen-free ovulation inhibitors.

Pill: pros and cons

Benefits of the micro pill

Many women find contraception with the pill to be convenient and uncomplicated. It is also one of the safest methods. Menstruation length and strength often decrease. Some preparations also have a positive effect on acne. But this is not an approved additional indication for the pill.

Rather, the following applies: Special hormone pills are sometimes used against acne, which also have a contraceptive effect. However, the preparations are acne medication. They should only be used if other therapies do not improve the skin disease.

Doctors examine a possible risk of thrombosis for those affected particularly carefully (more on this in the section "Side effects and contraindications") before prescribing a corresponding pill.

It has now been proven that combination pills can lower the risk of ovarian cancer and uterine cancer, even long after it has been stopped. With regard to other cancers, there are positive data in studies, but no reliable findings.

Disadvantages of the micro pill

Hormone preparations affect the natural hormonal balance of women. After the pill is stopped, it can take up to six months for the natural cycle to return. On the other hand, pregnancy can occur within a very short time.

Advantages of the mini pill

For example, a minipill is an option if women cannot tolerate estrogen well. Levonorgestrel-containing minipills are also suitable for contraception during breastfeeding, as the milk production and quality are not changed and the infant only takes in very small amounts of active ingredient. According to current knowledge, these do not entail any risks.

Disadvantages of the mini pill

Disadvantages of both types of mini pills are mainly menstrual disorders with irregular bleeding. This relates to both the time interval and the amount of bleeding.

How is the pill taken?


Depending on the type of preparation, there are different intake schemes. The first pill is always started on the first day of the menstrual period. The tablets are taken continuously. Classic preparations provide for a break in taking them. Then the pack is empty after 21 pills and a seven-day break. The hormone levels drop and the bleeding starts.

In this phase, too, there is contraceptive protection. However, the break must not exceed seven days: On the eighth day you start the new pack, regardless of whether the bleeding has ended or not.

If, in exceptional cases, a tablet has to be taken in addition - e.g. because of nausea with vomiting after taking it - it can be any one from the 21 blister of a single-phase combination pill. However, some preparations contain 7 active substance-free tablets in a blister strip for the hormone-free break.

These hormone-free tablets are of course not suitable for subsequent use. They actually only make normal use easier, because they mimic the tablet-taking break, so that after one pack is used up, the next one is on immediately.

In the case of multi-phase pills, the tablets must always be swallowed in the intended order, i.e. in the corresponding phase of the intake cycle. This of course also applies to the additional intake of a tablet if necessary.

There are differently designed packs, for example with 21, 24 or 26 hormone-containing tablets and 7, 4 or 2 active ingredient-free tablets.

Long-term use: goodbye bleeding

So-called long cycle intake has been practiced for a long time, for example for four months. There is generally no bleeding during this non-stop intake time, which many women find convenient.

Most gynecologists recommend low-dose micropills for this purpose, namely single-phase preparations of the "type 21", i.e. pills for 21 days with a seven-day break. Long-term mode then means: There is no break, instead the next pack is on.

The gynecologist sometimes considers a long-term mode for medical reasons, for example in the case of severe menstrual cramps and increased bleeding, including as a result of endometriosis. It is not yet clear whether the hormone levels, which are constantly elevated for a long time, pose health risks, although many women now practice long cycles.

If you are planning a long cycle intake, you should consult your gynecologist beforehand and, of course, have it examined first in the event of bleeding disorders.

The pill can also be used for two cycles continuously, for example to postpone the bleeding for a short time. Long-term use today is less a medical issue than a matter of personal choice.

Mini pill

The conventional minipill must be taken punctually at the same time every day, within a maximum of three hours. The whole thing over 28 days, without a break.

In the case of the desogestrel minipill, which is also used continuously, the maximum time span for late intake is twelve hours, as is the case with the micropill (see also the next section).

Forgot pill?

If taking the pill (micropill) has been postponed for more than twelve hours or if it has been forgotten, the contraceptive protection may be at risk. If the pill has been omitted more than once, there is no longer any protection. Whether contraceptive protection is still given or whether it is better to use additional methods depends on "forgetting once" which pill preparation it is, when the error occurred in the cycle or when the allegedly unprotected sexual intercourse took place.

However: in this situation, read the package insert carefully and seek advice from the gynecologist. Another option for emergencies: the morning-after pill, now available in pharmacies without a prescription. It should be used as early as possible.

Other confounders

Severe diarrhea or vomiting can make the pill less effective. In addition, medications, such as some anti-infection agents such as antibiotics, as well as anti-epileptics and some herbal remedies, such as St. John's wort preparations, can affect the safety of the pill, including the mini-pill. If necessary, seek advice from your doctor or pharmacy.

Do you need a prescription for birth control pills?
The doctors at Zava can help you quickly and easily - you can use the Zava website to request a prescription for the pill using an online questionnaire, 7 days a week. You can often pick up your contraceptive from a local pharmacy on the same day or have it delivered inconspicuously packaged to your desired address.

Request a prescription now

Traveling with the pill

With time differences of up to twelve hours - and that actually includes the vast majority of travel destinations from Germany - you can also take the pill at the holiday destination at the usual time (like at home, but local time). Thereafter, the intake continues at the usual hour (applies to micro pills).

The revenue gap increases with flights to the west. For extensions of more than eight hours, you may be able to take an "interim pill" (from a reserve pack) between the last and the next intake (this also includes postponements due to winter and summer time) to be on the safe side. But this is rarely necessary. Since there are different types of micropills and the timing of the forgotten pill in the intake cycle also plays a role, it is essential that you follow the information in the package insert for your preparation. Before you go on a long-haul trip, get advice from your gynecologist on what you should consider when it comes to the pill.

With the conventional minipill, the maximum intake interval is 24 + 3 = 27 hours. If there is a time difference of more than three hours, it is recommended to take another pill as a precaution after half a day and then to continue at the usual time (local time). Here, too, more detailed advice is recommended - depending on the travel destination, duration and direction.

Alternative contraceptives and, depending on the length of the journey, at least one reserve pack should always be in your luggage. They help maintain contraceptive protection in the event of clock changes and other problems such as traveler's diarrhea.

Side effects and contraindications to the pill

Depending on their composition, contraceptive pills can have a wide variety of side effects and risks. The list of risks and contraindications is correspondingly long (see package insert).

The individual tolerance can be very different depending on the preparation. For example, some women report nausea, weight gain, mood swings, intermenstrual bleeding, headaches or decreased desire for sex (loss of libido, see also section "Depression" below).

Some of these side effects may improve with prolonged use. Sometimes it also helps to change the preparation in consultation with the doctor. But then a new first year of use begins. It has been shown that certain side effects such as thrombosis can occur more frequently in the first year of use or when taking it again after an interruption of more than four weeks.

What is the risk of a vein thrombosis?

In the case of a thrombosis, a clot of blood constricts or closes a blood vessel, for example a vein in the leg. Fortunately, this is a rather rare side effect overall. The problem: the clot or parts of it can also be flushed with the bloodstream into other vessel sections and block them (thromboembolism, for example pulmonary embolism).

In this respect, the risk must be taken seriously, albeit very rarely. This is especially true for women with thromboses or embolisms in close relatives or in their own past. The latter is a contraindication to the micropill.

! Warning: Possible warning signs of a thrombosis and embolism include: Unilateral swelling of a leg and / or leg pain, sudden shortness of breath, coughing, rapid breathing, significant chest pain, unilateral sensory disturbance, weakness (face, arm, leg), sudden visual disturbance, Dizziness or weakness. Call the emergency services immediately (emergency number: 112).

Thrombosis Risk: Data and Facts

Micro-pills with newer progestins such as gestodene, desogestrel or drospirenone have a higher risk of venous thrombosis / embolism (VTE; nine to twelve cases per 10,000 women annually) than those with gestagens that have been used for a long time, according to the evaluation of the study by the European Medicines Agency (EMA) Levonorgestrel, norgestimate, or norethisterone (five to seven per 10,000 women per year).

For the progestins etonogestrel and norelgestromin, six to twelve VTE events per 10,000 user-years were reported. An international study published in the meantime in 2014 put the differences for the progestogen drospirenone into perspective, while an English study published in 2015 again underlined the higher risk of thrombosis and embolism, especially for the newer gestagens.

There were 13 VTE events per 10,000 users with drospirenone and 14 with desogestrel. An American analysis of 22 recently published studies published together with the World Health Organization (WHO) in 2018 also confirms the comparatively lower thrombosis risk of levonorgestrel.

For comparison: Out of 10,000 women who do not take a contraceptive pill (estrogen-progestogen combination) and are not pregnant, about two develop venous thrombosis every year. However, factors such as hereditary predisposition and natural hormonal changes also have an influence on the risk of thrombosis. During pregnancy, for example, up to 29 out of 10,000 women develop a thrombosis / embolism.

For some gestagens, more precise data are still lacking.

Swell: European Medicines Agency (EMA): International study: Contraception. 2014 Apr; 89: 253-63. English study: BMJ 2015; 350: h2135; American study in collaboration with the WHO:

Swelling, pain, or tenderness in the leg can be warning signs of venous thrombosis

© iStock / szefei

As a result, combination pills that contain a progestogen such as levonorgestrel, norethisterone or norgestimate in addition to a low-dose estrogen have the lowest risk of thrombosis according to the current study situation (see above). For example, they can be considered for first-time users.

The influence of the minipill on the risk of thrombosis is evidently not comparable with that of the estrogen-containing combination pills. Ultimately, it is assessed as lower or even not increased. For women who have already had a venous thrombosis, only a minipill can therefore be considered if they want to use a pill for contraception.

Can one recognize a tendency to thrombosis?

Partly yes. The most common hereditary tendency to thrombosis (thrombophilia), for example, is APC resistance, usually as a result of a change in the coagulation system (so-called Factor V Leiden (FVL) mutation). APC, the activated protein C, is an endogenous inhibitor of coagulation, which in the event of a mutation cannot work properly (resistance). In healthy female relatives of family members who have thrombophilia, testing can be useful to assess the risk of thrombosis before hormonal contraception or pregnancy. For this purpose, the gynecologist and family doctor will advise the woman concerned and possibly refer her to a coagulation clinic for clarification.

What other problems are there?

The risk of serious side effects increases with the individual risk factors. This can also apply to younger women.

It is therefore generally very important in a conversation with the doctor to find out whether the pill is the right contraceptive, what side effects can occur, what warning signs there are and whether certain risk factors or diseases speak against taking it.

Beyond the age of 35, the risk of further undesirable side effects, such as a heart attack or a stroke, increases, especially with micropills.This is even more true if a woman smokes a lot, is severely overweight or has high blood pressure. These diseases also have to do with thrombosis, this time in the arterial vessels (arteries).

Blood pressure may rise while taking the pill. Women over 35 years of age who smoke heavily should not use the combination pill. The contraindications also include, for example, liver diseases or diabetes mellitus, which has existed for a long time, is difficult to regulate or has led to vascular complications. The same applies to hypertension that is not easily manageable.

Combination pills are also not suitable after a heart attack, previous (or existing) thromboembolism or breast cancer less than five years ago. In the case of breast cancer, doctors weigh up further criteria.

Because: Women who take the pill have a slightly higher risk of breast cancer. The risk of cervical cancer is also increasing. It falls again within ten years of stopping the hormones.

A rather rare side effect of therapies with sex hormones in general is the appearance of yellowish-brown pigment spots (chloasma) on areas of the skin exposed to the sun, especially on the face. Women who have already had this experience during pregnancy sometimes also tend to do so more if they take sex hormones.

If the risk is known, doctors are more likely to recommend a non-hormonal method of contraception. Otherwise there is the advice - which must be discussed in more detail - to avoid direct sunlight and UV light (solariums) while using the hormones. The regression of a chloasma can take a relatively long time. It is best to ask your gynecologist about the problem before prescribing a hormonal contraceptive.

Menstrual cycle and menstrual disorders

The doctor will also consider possible other side effects, such as menstrual disorders. Older progestins may have disadvantages here. But even with modern micropills with a very low proportion of estrogen, slight spotting can occur in the first few months of use. If the pill continues to be taken correctly without changing anything, the doctor will check whether another preparation is cheaper.

In fact, taking the pill can regularize a hormonally unstable cycle. However, other causes, including pregnancy, must be ruled out. Sometimes an irregular cycle before the "pill time" remains irregular afterwards. If you have not had any problems taking a contraceptive pill, there is usually no reason to change the preparation.

Pill and depression

A study published in 2016 suggested such a connection on a larger scale for the first time. The results were based on the analysis of two Danish health registers with over a million records. However, the study also showed differences between the various hormonal contraceptives.

Women who, after starting hormonal contraception, suffer from symptoms such as persistently nervous or depressed mood, lack of energy, changes in libido or depression, have been recommended for a long time to consult their gynecologist.

The importance of this recommendation is underlined by another study published in 2018 by the same Danish working group. It found a connection between the use of hormonal contraceptives and an increased risk of suicide. So the analysis wasn't just about the pill. However, it is an epidemiological population study using data from health registers and not a clinical study.

At the instigation of the drug authorities, warnings can now be found in the product information and instructions for use of the products for hormonal contraception, which draw attention to suicidality as a possible consequence of depression. Affected women should not wait long when they experience depressive symptoms, but seek medical advice from their doctor quickly, even if they have only recently started treatment.

Safety of the pill

The Pearl Index serves as a measure of contraceptive safety. The smaller it is, the safer the method. For example, a Pearl Index of 3 means that three out of 100 women who have used the same contraceptive for a year will become pregnant. At 0.3 it is three out of 1000 women. The lower the Pearl Index, the safer the method. However, no method is one hundred percent reliable, because practical application plays a major role.

The pearl index for micropills is 0.1 to 0.9. With the conventional minipill it is between 0.5 and 3 to 4. Here, the accuracy when taking has a very clear effect. A value of 0.4 is given for the minipill containing desogestrel.

Conclusion: All in all, the birth control pill is a contraceptive that has been tried and tested for decades and is well-tolerated by many women. Nevertheless, you should ask your doctor carefully before using it for the first time and decide in peace. Important: The pill protects against unwanted pregnancies, but not against sexually transmitted diseases.