Must Know Facts About Oral Contraceptives!


Oral contraceptives are hormone-containing pills that are swallowed to prevent pregnancy. They are  also called birth-control pills. Oral contraceptive pills (OCPs) have become safer and more effective since their approval by the Food and Drug Administration (FDA) in 1960.1 Unplanned and unintended pregnancy is a significant public health concern in Europe. Despite the widespread use of condoms and oral OCPs in Britain, approximately one in five pregnancies are still unplanned.2

Having a thorough knowledge of OCPs is crucial because their effects can vary from person to person. There is a wide variety of pills available for you to choose from. You have the freedom to select the ones that will work best for your needs. The purpose of this article is to inform you about the different types of oral contraceptive pills, their advantages and possible adverse effects.

Key facts about oral contraceptives 

The journey of OCPs since its inception has been remarkable. Here are some noteworthy facts:3,4

  • Around 25% of people assigned female at birth (AFAB)aged 15- 44 use the pill as their first choice for birth control
  • In about 14% of cases, OCPs are used for non-contraceptive reasons  
  • The use of OCP decreases the risk of ovarian cancer by 27%
  • The risk of endometrial cancer is reduced by 50% in women taking OCP
  • There is a 20% higher risk of breast cancer with hormonal contraception 

What are effective birth control measures?

Did you know around 92 - 99% of pregnancies can be avoided if contraception is used perfectly? Knowing which type of contraceptive is best for your body is crucial and depends on your age, smoking history, specific requirements, and any associated health factors. Firstly, let's review the birth control options available before we learn more about OCPs:3,4,5,6

  • Hormonal methods - These include oral contraceptive pills, injections, patches and vaginal rings like NuvaRing
  • Intrauterine device - The copper coil is inserted into the uterus that prevents conception by copper-induced alteration of cervical mucosa. Some Intrauterine Systems like Mirena coils release hormones that prevent fertilisation and implantation
  • Barrier methods - It includes both male and female condoms
  • Option based on fertility awareness - These methods involve identification of the fertile period  of the menstrual cycle and avoiding intercourse during that critical period
  • Permanent method - Sterilisation methods such as vasectomy and tubectomy  prevent permanent conception
  • Emergency contraception - You can opt for this method when you fail to use any contraception during intercourse

Types of oral contraceptives

You should be familiar with the types of birth control pills available if you intend to use them. The general practitioner (GP) and nurses can also help you understand the options before making a decision. Here is the list of different kinds of OCPs that may help you to make an apt choice:3

Types of pillsFormulationWhen to take pills
Mini pillsProgestin-onlyTake one pill every day at the same time
Combined pillsOestrogen and progestinDepends on the type of combined pills
Cyclic pillsTake pills for 21-24 days, followed by pill-free days of 4 -7
Extended pillsTake pills for 3 months, followed by a one-week placebo
Emergency contraceptionSingle pill with progestinTake as soon as possible and within 48 hours of unprotected sex

Table 1: Types of oral contraceptives

The oestrogen component in OCPs can be estradiol, ethinylestradiol, or estetrol. Similarly, some progestin components in OCPs are norethindrone acetate, levonorgestrel, norgestimate, and drospirenone. These pills release a controlled dose of hormones into the blood to prevent pregnancy.3 You must follow the regimen without missing the pills for better results.

How do contraceptive pills work?

The hormones found in contraceptive pills create an unsuitable environment for pregnancy. The three fundamental mechanisms that inhibit pregnancy are:3,7

  • Pills prevent the release of eggs from the ovary
  • Thicken the mucus and stop sperm from meeting the egg for fertilisation
  • Pills might interfere with the implantation of a fertilised egg by thinning the endometrium

Who should avoid taking birth control pills?

Avoid taking birth control pills if you have pre-existing medical conditions or risk factors. The list of some of the known situations where a contraceptive pill may not be the suitable option:3,8

  • Smokers with age more than 35
  • Stroke or any disease causing narrowing of arteries
  • Uncontrolled high blood pressure
  • Heart disease
  • History of thrombosis or blood clot
  • If you are pregnant
  • Diabetes with underlying complication
  • Gallbladder or liver disease
  • Severe degree of migraine
  • History of breast cancer or endometrial cancer
  • Those on medication for seizures

Therefore, you must discuss your medical history with your GP before choosing hormonal contraceptives such as OCPs. Also, awareness of risk factors can help you make smart decisions regarding contraception and reduce the possibility of OCP-associated life-threatening outcomes.

Benefits of taking oral contraceptives

The benefits of OCP have made it one of the most popular methods of contraception in the recent decade. Some of the significant benefits of using OCPs are:3,7,9

Contraceptives benefits

It can prevent pregnancy in 99% of cases if used correctly

Non contraceptive benefits

  • Helps in reducing menstrual blood flow
  • Makes menstrual bleeding less painful
  • OCPs decrease ovarian and colon cancer risk
  • Decreases endometriosis associated chronic pelvic pain
  • Can protect against pelvic inflammatory diseases
  • It can be used for the treatment of acne

Side effects and their management

Like any other medication, you can have the side effects of using oral contraceptives. The potential side effects of using OCPs are:3

Common adverse effectsSerious but uncommon adverse effects
- Headache
- Nausea
- Abdominal cramps
- Tender breast
- Discharge from the vagina
- Irregular menstrual bleeding
- Mood swing
- Flaring of pre-existing hypertension
- Blood clots
- Stroke
- Myocardial infarction (Heart Attack)
- Impaired lipid metabolism
- Liver disease
- Small risk of cervical cancer and breast cancer

Table 2: Side effects of oral contraceptives


It is important to appropriately handle the potential side effects of OCPs. Mild afte - effects will go away when you continue taking your OCP or switch to a different OCP.3 However, fatal side effects, like other medical conditions, may require immediate intervention.

Regular check ups for pill users

Regular yearly check - ups, discussing potential side effects, addressing missed pills, and highlighting non-contraceptive advantages are important.9 In addition to a physical examination and blood pressure monitoring, your GP may suggest that you undergo a specific test: 3,9

  • Coagulation tests
  • Lipid profile
  • Cervical PAP smear
  • Thyroid function test
  • Test for blood sugar level


What should I do if I miss a pill?

The options available for you in case of missed pills are:

Missing only 1 pill: You must take the last missed pill as soon as you remember and resume regular pill-taking.

Missing 2 or more pills: You must take the last missed pill, leaving any earlier missed pills. Then resume regular pill-taking. Additionally, use extra protection, such as a condom for the next 7 days.

However, the instructions in case of missed pills may vary with the type of OCPs, number of missed pills and type of regimen. Therefore, you should read the instruction leaflets or discuss your issues with a healthcare provider.

Do birth control pills protect against sexually transmitted Infections?

No, pills do not protect you from sexually transmitted infections (STIs). Barrier methods of contraception, such as condoms, can help prevent STIs if used appropriately.

Can I take pills after having a baby?

It depends on whether you are breastfeeding or not. If you are breastfeeding, you should avoid taking pills until 6 weeks after the birth of a child. If not breastfeeding your child, you can take contraceptive pills on day 21 after the birth.

Are contraception services free?

In the UK, contraception services are free to anyone through National Health Services (NHS). These services are available at:

  • GP surgeries
  • Sexual health clinics
  • Common contraception clinics

Can I take contraceptive pills If I am on medication?

Some medicines might interfere with oral contraceptives. It includes:

  • Antibiotics such as rifampicin and rifabutin
  • Antiretroviral drugs such as ritonavir, nevirapine, etc
  • Some antiepileptic drugs
  • Herbal products like St John's wort

Therefore, you must provide drug-related history while availing of services at any health clinic.

Should I stop taking pills if I have surgery?

For minor surgeries, no precautions are required. However, oral contraceptives must be stopped 4 weeks before major surgery or immobilisation like a leg fracture.


Oral contraceptives are widely used birth control pills globally. Different types of OCPs are available in the market and can be tailored based on your requirement. Other than the traditional OCP regimen, you can also use it for emergency contraception.

These pills offer advantages beyond contraception, such as minimising blood loss during menses, acne treatment, etc. Along with the benefits, you must be aware of the side effects of taking OCPs. In certain medical conditions, OCPs are prohibited due to the life-threatening consequences. You should consult with your GP, nurses, or healthcare providers before selecting any medication or switching from one type to another.

Oral contraceptives can provide effective contraception when used correctly and judiciously. If you have missed any birth control pills, taken medication that interferes with them, recently given birth, or have upcoming surgeries, seeking advice from a healthcare clinic can help answer any questions.

By being well-informed about these birth control pills, you can make better decisions that avoid unplanned pregnancies, regulate birth spacing, and minimise complications. A well-thought-out decision could help you build a fulfilling reproductive and sexual life.


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  2. French RS, Gibson L, Geary R, Glasier A, Wellings K. Changes in the prevalence and profile of users of contraception in Britain 2000–2010: evidence from two National Surveys of Sexual Attitudes and Lifestyles. BMJ Sex Reprod Health [Internet]. 2020;46(3):200–9. Available from:
  3. Cooper DB, Patel P, Mahdy H. Oral Contraceptive Pills. In: StatPearls. StatPearls Publishing, Treasure Island (FL); 2022. PMID: 28613632.
  4. Westhoff CL, Pike MC. Hormonal contraception and breast cancer. Contraception [Internet]. 2018;98(3):171–3. Available from:
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  6. Grimes DA, Gallo MF, Halpern V, Nanda K, Schulz KF, Lopez LM. Fertility awareness-based methods for contraception. Cochrane Libr [Internet]. 2004;2012(5). Available from:
  7. Hee L, Kettner LO, Vejtorp M. Continuous use of oral contraceptives: an overview of effects and side-effects: Continuous use of oral contraceptives. Acta Obstet Gynecol Scand [Internet]. 2013;92(2):125–36. Available from:
  8. Lesnewski R. Initiating Hormonal Contraception. Am Fam Physician. Am Fam Physician. 2021;103(5):291–300.
  9. Sattari M, Mokhtari Z, Jabari H, Mashayekhi SO. Knowledge, attitude and practice of pharmacists and health-care workers regarding oral contraceptives correct usage, side-effects and contraindications. East Mediterr Health J [Internet]. 2013;19(6):547–54. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Rajni Sarma

MBBS, MD from North-Eastern Hill University, India
MSc in Molecular Pathology of Cancer, Queen's University, Belfast, UK

I worked as a medical doctor for almost eight years before applying to Queen’s University Belfast for MSc in Molecular Pathology of Cancer. My outstanding verbal and demonstrative skills have helped me to get distinction in my master’s program.

However, I found my true passion in medical writing. Therefore, after I graduated from Queen’s University, I decided not to join any laboratory but to restart my career as a medical writer.

The topics that intrigue me are haematology, oncology, rare diseases, immunology, gynaecology, molecular pathology, targeted therapy, and precision medicine. I am currently an intern at Klarity and a volunteer medical writer for a health and wellness website. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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