Monday, August 1, 2011

Types Of Oral Contraceptive Pills - A Comparison

Hormonal contraceptives are used by many women for birth control. A little awareness about the pills and other methods of contraception helps you select the method or type of pill that suits you the best. Prior knowledge of the side effects and contraindications is also necessary. These have been discussed in previous posts. Today we'll see what the different types of oral contraceptive pills are and compare them.

1. Combined Oral Pills (Monophasic)

These contain a mixture of the two female hormones oestrogen and progesogen. All tablets of the pack contain the two hormones in the same amount.

Dose -

  • Starting from the 5th day of the cycle, tablets are taken for 21 days.
  • New pack is started after a gap of seven days.
  • In some brands you will get a pack of 28 tablets instead of 21 tablets.
  • This is because they include iron tablets i.e. the 7 tablets of different colour in the pack.
  • This is done in order to make the use of tablets simple for the women.
  • Tablets are to be taken at a fixed time of the day, preferably after a meal.

Mode Of Action

  • It suppresses the FSH and LH hormones released from the pituitary gland and consequently prevent ovulation.
  • Progestogen causes atrophic changes in the inner lining of the womb or uterus and thus prevents implantation.
  • Progestogen also makes the cervical mucus thick and therefore impermeable to the sperms.

Faliure rate

Faliure rate is only 0.1% which is lowest among all contraceptives in use today.

Caution required

  • During the first cycle, use of an additional method of birth control is advised since ovulation may not be suppressed by then.
  • However starting the pill on the first day of the cycle reduces this risk.
  • If you forget to take a tablet once, then take two tablets on the next day.
  • If you forget to take the tablet twice or more then you are no longer protected and must use a barrier method like condom for that cycle.

Side effects and contraindications

Read the previous posts:


2. Triphasic Combined Pills

Pills contain a combination of oestrogen  and progestogen  in three sets of combination ratio.

  • During first six days 30 micro gram oestrogen (EE2 = ethinyloestradiol) + 50 micro gram progestogen (LNG=levonorgestrel)
  • Next five days 40 micro gram oestrogen + 75 micro gram progestogen
  • Last ten days 30 micro gram oestrogen + 125 micro gram progestogen

Dose -
Same as monophasic combined pills

Failure rate -
These are as effective as the monophasic combined pills.

Advantage over monophasic pills

Triphasic pills do not have a bad effect on the carbohydrate and lipid metabolism like monophasic pills and therefore can be used by the diabetic women.

Disadvantage over monophasic pills

While monophasic pills also control the amount of flow during periods and therefore useful in women with menorrhagia i.e. with excessive bleeding during menses, same is not possible with the triphasic pills.

3. Progestogen-Only Pill (POP)/Minipill

These contain only progestogen and no oestrogen.

Dose -

  • Tablet is taken daily without a break.
  • Pill should be started within 5 to 7 days of menstruation

Caution required -

  • Pill should be taken at a fixed time daily +/- three hours.
  • If you forget to take the pill as mentioned above, use additional method like condom for 48 hours and continue taking the pill as before.
  • Additional method is also advised in the first 48 hours of the first cycle or pack.

Failure rate -

Failure rate is 2-3% i.e. higher than combined pill.

Advantage over combined pills
Mini pill does not have the side effects related to oestrogen.

I'll discuss more about the advantages, drawbacks and contraindications of minipill in the next post, Minipill - Benefits Drawbacks and Contraindications

Please Note: This post is informative in nature and cannot replace a face to face consultation with your doctor. Therefore, use of any contraceptive with the advice of the gynecologist is recommended.