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    Oral Contraceptives: Everything You Need to Know About the Pill

    Updated 17 February 2022 |
    Published 07 September 2018
    Fact Checked
    Reviewed by Kate Shkodzik, MD, Obstetrician and gynecologist
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    Who invented oral contraceptives? How do they actually work and change your body? Today we’re answering the most pressing questions about the pill.

    How were first oral contraceptives invented?

    The invention of the first contraceptive pill is said to have been one of the most important discoveries of the 20th century.

    Getting to the buyers was not easy, however. In the 1950s, birth control was considered immoral in many U.S. states.

    The first pills, created by Dr. Gregory Pincus, went on sale in 1957. To avoid accusations of immorality, they were recommended as “a means to solve the problems of irregular cycles.”

    However, the inventors did not forget to point out its contraceptive properties as a “side effect.”

    Doctors immediately noted the epidemic of “irregular cycles.” Just two years later, about half a million women in the U.S. began to use the pills due to its alluring “side effect.”

    Planning to take oral contraceptives? Consult your doctor first

    Most women believe they can choose their own combined oral contraceptives (COCs) or just take the same ones that were prescribed for their friend. This is a very common (and dangerous) misconception!

    Based on your age and medical history, the doctor will prescribe the most suitable hormone combination and dosage for you.

    Medication for an 18-year-old girl is different than that for a 30-year-old woman. Different hormone dosages will help a girl with acne, a woman suffering from painful menstruation, or a mother of several children.

    There is no perfect pill for all. Consult your gynecologist to find the optimal COCs.

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    The most important thing while taking oral contraceptives

    When taking oral contraceptives, keeping to a schedule is an important thing.

    Such medicines are effective if their concentration in the body is constantly maintained at the same level. Taken on time, a birth control pill guarantees a continuous contraceptive effect. Consequently, it reliably protects against an unwanted pregnancy.

    For best results, oral contraceptives should always be taken at the same time every day.

    Can you gain weight from taking oral contraceptives?

    Often, women don’t take birth control pills for fear of gaining weight. Let’s see if that fear is justified!

    The first oral contraceptives actually contained very high hormone doses (twice as much as in modern pills), so they could cause metabolic disturbance and weight gain. After numerous laboratory tests, the dose was reduced.

    Recent studies have not revealed a direct link between taking birth control pills and gaining weight. In fact, women often put on weight because of their age and lifestyle habits.

    Sometimes, a slight increase in weight can be associated with water retention or an increased appetite while taking combined oral contraceptives (COC).

    Flo users share their stories: conceiving after the pill

    I didn't stop birth control until the week of my wedding. I started on Flo straight away. I knew it would take a few months at least to settle into a routine and for the side effects of the pill to disappear. I got pregnant on our fourth attempt. I'm now 8 weeks pregnant. I definitely recommend inputting BBT (basal body temperature) as that gave me a much better idea of ovulation.

    How do mini-pills work?

    There are two different kinds of pills: combined oral contraceptives (COCs), which contain estrogen and progestin, and the mini-pills, which contain progestin only.

    The COCs primarily hinder the ovulation process. The mini-pills act differently. They affect cervical mucus, make it impenetrable for sperm, and prevent endometrial growth.

    Mini-pills were designed as an alternative for women who have contraindications to combined oral contraceptives (COCs).

    In comparison with the latter, mini-pills are as effective as IUDs and contain only one hormone — progestin. Most of these pills do not prevent ovulation and allow the occurrence of a regular menstrual cycle. How do they work?

    Mini-pills alter the quality of cervical mucus. It becomes denser and forms an impenetrable barrier against sperm. If sperm still manage to go through and fertilize the egg, another important effect will be triggered. This type of contraception changes the uterus lining and prevents the egg from implantation.

    Many women believe that they will still ovulate while on the mini-pill. This is not entirely true.

    The presence or absence of ovulation depends on the body’s individual peculiarities and the generation to which the contraceptive belongs. Mini-pills contain progestin, a form of the hormone progesterone, which plays an important part in the menstrual cycle and pregnancy. Depending on the generation of the contraceptive, it may contain different progestin derivatives.

    They are primarily responsible for whether the woman will ovulate. The first generation mini-pills prevent ovulation in 60% of women, while the more modern pills achieve this effect in 97% of users.


    What to do if you miss a birth control pill?

    The missed combined oral contraceptive pill should be taken immediately as soon as you remember it, and the next one, according to the set schedule. That is, within one day, you will have to take two pills instead of one. From there, continue taking the medicine according to the regular schedule.

    In most cases, one missed birth control pill should not be a problem. The concentration of the drug in the body will not change because of that, and the chances of getting pregnant will still be negligible. However, if this happened to you in the first month of taking the medication, it is better to play it safe and use additional contraception (condoms, for example) for the next 7 days.

    If the delay is less than 3 hours in taking the mini pill, take the missed pill right away, and the next one, according to the usual schedule. If the delay is more than 3 hours, take the pill immediately, but use barrier contraceptives for the next week.

    Flo users share their stories: went off the pill and got pregnant right away

    I downloaded the app to track my periods after deciding to come off the pill, not to start trying but to give my body a rest. As soon as we said, “Okay, let’s see what happens,” I was pregnant! I’m still in shock because according to when I should have been ovulating, I didn’t think I could have gotten pregnant! Shows how quick it can happen. I’m now 7 weeks, and it just about feels real now. I’m excited and nervous as to what’s to come!

    Forgetting about birth control for a long time: long-acting reversible contraception

    Women are busy with a great number of things and often dream about minimizing the need to worry about contraception on a daily basis. Modern means are making it possible to forget about contraception for 3, 5, or even 10 years.

    Long-acting birth control methods include hormonal and copper intrauterine devices, as well as implants. The latter protect against unwanted pregnancy for up to 4 years.

    Hormonal intrauterine devices should be replaced every 3–6 years, depending on the manufacturer's recommendations. Copper intrauterine devices have the longest effect. They can provide protection for 5–10 years, depending on the model.

    When choosing a contraception method, be sure to consult a doctor who will help you pick the contraceptive that fits you best in terms of use and effect.

    Frequently asked questions about oral contraceptives

    How long should you stay on the pill?

    As long as you do not have any medical reason to not continue taking the Pill, you can continue staying on the pill for long. Many females are on it for years, whether it helps in regulating their menstrual cycle, offer protection against pregnancy, treat cramps, or for hormone replacement therapy.

    Can I get pregnant on the pill?

    Yes, you can get pregnant on the birth control pill. No contraceptive methods including birth control pill are utterly foolproof. However – if it is taken as directed — the pill is over 99% effective at preventing pregnancy. If you do not take the pill correctly and as directed by your doctor, your probability of an unexpected pregnancy rises.

    Can you get pregnant as soon as you stop the pill?

    The birth control pill has no effect on your fertility. When women stop to take the birth control pills, they temporarily extend the time to conception, some females will get pregnant immediately after they stop popping the pill. Hence, it is important for a woman to be ready to take utmost care of her body during her pregnancy, as soon as herself and her partner start making an attempt to conceive.

    Is birth control 100% effective?

    Birth control methods are 91% - 99% effective in preventing pregnancy. The pill is one of the most reliable forms of birth control/contraception, offering the highest degree of protection against pregnancy when taken as directed. However, 91% - 99% still means there are some chances of pregnancy. Women who become pregnant while using contraceptive either skip one or more doses; take a pill at a different time from the directed one; take medicines like antibiotics that interfere with the performance of birth control pills in your body, or have unprotected sex too soon after starting the pills.

    Is birth control safe long term?

    There is no one best method of birth control. When hormone levels in the body are increased unnaturally for a long duration of time, it results in unpleasant side effects. All birth control methods - pill, implant or patch have some side effects and long-term risks. There are different long-term side effects of birth control methods which include; Cardiovascular Issues, Diabetes, Cancer Risk, Deep Vein Thrombosis, Depletion of Nutrients, Pituitary Gland Problems, Gallstones, and Yeast Infections.

    Do you ovulate on birth control?

    No, people who are on birth control pills or oral contraceptives do not ovulate. Birth control pills are designed to stop ovulation. The pill is more than ninety-nine percent effective when used perfectly. Ovulation is defined as a process in which the ovary releases a mature egg.  Birth control pills contain progesterone and estrogen that prevent ovulation and in the absence of ovulation, there will be no egg to be fertilized. 

    How many birth control pills can you miss before getting pregnant?

    If you miss any pills, the risk of becoming pregnant increases. The pill is not infallible.  if you miss more than 1 dose in a pill pack or per cycle, the chances of pregnancy can suddenly become very real, indeed. Risk of pregnancy is high if you miss your pill dose more frequently and if the gaps between the doses get wider.

    How soon after stopping the pill can I ovulate?

    Ovulation in the 1st cycle once you stop taking the pill varies from a few weeks to several months. For some women, ovulation begins within a week and for some, it may take 1 to 3 months. Some women become immediately pregnant after they stop taking the pill. Scientific evidence even says that you are the most fertile right when you stop taking the pill.

    Can you start the pill at any time?

    Yes, you can start the pill at any time after you pick up your prescription. You can start taking the pill at any time throughout the month but the time it takes for the birth control pills to take effect will depend on the kind of pill you are taking. Most females use combination pills (pills having both estrogen and progestin hormones). In case of combination pills, if you start taking within the first 5 days of the start of your monthly period, protection from pregnancy begins right away. If you begin at any other time in your monthly menstrual cycle, pregnancy protection will begin after 7 days. 

    Does birth control cause low estrogen?

    Birth control pills suppress our body’s own natural production of the hormone called estrogen. Birth Control Pills interfere with the body’s normal hormone production with synthetic estrogen version, which stops ovulation, tricking the body the into notion that it is pregnant all month. It can be said that the birth control pills elevate estrogen levels causing several side effects like nausea and headache.


    “Fact Sheet – Hormonal Contraception.”, The Patient Education Website of the American Society for Reproductive Medicine, Accessed 27 Sept. 2021, “The Progestogen-Only Pill – Your Contraception Guide.” Nhs Choices, NHS, 2 Feb. 2021, “Contraception: Overview.” [Internet]., U.S. National Library of Medicine, 29 June 2017, “A Timeline of Contraception.” PBS, Public Broadcasting Service,

    History of updates

    Current version (17 February 2022)

    Reviewed by Kate Shkodzik, MD, Obstetrician and gynecologist

    Published (07 September 2018)

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