What do the pills contain?

The combined oral contraceptive pills contain 2 synthetic versions of female hormones: estrogen and progesterone. The prills should be taken on a daily basis to prevent unplanned pregnancy. Combination birth control pills are a reliable form of contraception that can be easily reversed, with fertility returning to normal almost immediately after stopping the pills.

Discussing combined oral contraceptives in detail

Most of the combined oral contraceptive pills available in Singapore are monophasic 21-day pills. After 21 consecutive days of taking these hormone pills, there should be a 7 day pill-free interval. Some brands may come with placebo pills during the pill-free days to help with the development of a regular habit of taking daily pills.

The contraceptive pills can also be taken continuously without a pill-free interval for longer than a month. Starting a new pack of pills immediately after finishing the current pack of pills without a break is usually done in cases where there is a need to delay the menstrual cycle.

For new users, the pill should be started on Day 1 of the menstrual cycle for it to be effective immediately post-menstruation. If it is started at any other time of the menstrual cycle, additional barrier protection such as condoms should be used for 7 days before it is safe to have unprotected intercourse.

The pill requires self-discipline and should be taken around the same time on a daily basis. If you miss a pill, take it as soon as you remember. If you miss more than one pill, an additional 7 days of barrier protection may be needed to prevent unplanned pregnancy.

Why are combined oral contraceptives so effective

It works to prevent pregnancy through several ways –

  • By preventing ovulation (the release of an egg by the ovaries every month)
  • By thickening the cervical mucus and acting as a barrier for sperm passing into the uterus to minimise the risk of fertilisation
  • By thinning the lining of the uterus, making implantation unfavourable should fertilisation of an egg somehow occur

Who should use this form of contraception?

It can be used by all women of reproductive ages looking for a short-term non-barrier form of contraception. It is also suitable for women suffering from certain medical conditions that cause irregular menstruation, such as Polycystic Ovarian Syndrome (PCOS); women with severe menstrual cramps (dysmenorrhea); or heavy menses (menorrhagia); and premenstrual syndrome symptoms (PMS). It is also beneficial for women suffering from acne and is widely used by skin specialists for this condition.

Who should not use this form of contraception?

Certain groups of women with pre-existing medical conditions like poorly controlled high blood pressure, migraines with aura, breast or hormonal related cancers, liver or gallbladder conditions and blood clots (thrombosis) should avoid using this pill. Women with a family history of breast cancer, major cardiovascular diseases and thrombotic tendencies should also avoid using this treatment.

It is also not ideal for smokers, especially those aged more than 35 year old.

Some medications may also interact with and decrease the efficacy of the combined oral contraceptive pill, such as certain groups of antibiotics and antiepileptics. It is good to ask about drug interactions with the doctor each time you are prescribed with any new medication.

What are the types and examples of these pills

Types of COCPs packaging

Examples of brands available in DTAP clinics

21 days pill

Yasmin, Microgynon-30, Mercilon, Diane-35

28 days pill (24 active + 4 placebo)


Different brands and formulations on the market vary slightly in the types of synthetic estrogen or progesterone they contain. However, they are all designed to mimic the natural menstrual cycle to prevent unplanned pregnancies.

Benefits and possible side effects


  • Allows for sexual spontaneity 
  • 99% Efficacy in preventing pregnancy if taken consistently and correctly
  • Helps with symptoms of irregular, heavy or painful periods, as well as premenstrual syndrome
  • Some types of the combined oral contraceptive pill can help with acne
  • Reduces the risk of ovarian and uterine cancer

Side Effects

Common Side Effects (which usually resolves within first few months of pill taking)

  • Breakthrough bleeding, irregular spotting
  • Nausea, abdominal pain, bloating
  • Headache
  • Breast tenderness
  • Mood changes/Mood swings
  • Weight changes

Long term Side Effects

  • Possible elevation of blood pressure
  • Possible increased risk of rare but serious health conditions like thrombosis (blood clots), especially in high risk individuals
  • Possible increased risk of breast cancer, especially in high risk individuals
  • For those suffering from migraine with aura, there is a slightly increased risk of developing stroke while on this pill
  • The pill efficacy may be affected by drug interactions with other medications, or if you are unwell with vomiting or diarrhoea
  • Does not confer protection against Sexually transmitted Diseases (STDs)

Different individuals may experience different side effects while on different brands of contraceptive pills. It is important that you have discussions with your doctor to find the right type of contraception, especially if there are any prolonged undesirable side effects.

Questions that are asked on Google:

Does the combined pill stop periods?

  • The pill is more commonly known to cause irregular periods, or breakthrough bleeding especially in the first few months of starting on the pill. It is not supposed to stop period altogether, but it does lighten the period flow. In some women who want to use the pill to stop or delay a cycle, it is possible to do so by taking the contraceptive pill packs continuously without a pill-free interval in between.

Does the pill make your boobs grow?

  • Some patients report a side effect of tender and enlarged breasts. This can be experienced in some users due to the hormonal content in the pills. Any side effects of tenderness and enlargement should be temporary and reversible once the pill consumption is stopped.

Does birth control make your hips wider?

  • Some users experience side effects of weight gain in general while on certain types of combined contraceptive pills. Women may feel that their hips are wider due to the way fat is distributed in the body, rather than a direct effect caused by the pill.


Dr. Goh Lit Ching


For more information, please visit DTAP Clinic website, www.dtapclinic.com or email them at hello@dtapclinic.com.sg

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *