Our doctors answer the most common questions around the contraceptive pill…
Will the pill make me fat?
It’s very rare for the pill to cause weight gain. Some pills may cause slight weight gain through fluid retention, but as with many side effects of the pill, this is usually temporary. If you think that you’ve gained a bit of weight or are feeling bloated after starting a new pill, wait at least 3 months to see if this side effect passes.
If you’re one of the very few women who does experience weight gain, have a chat with your doctor about changing your pill. Different brands of pill have different levels of hormones, so a different pill will likely cause you fewer side effects.
The weight gain myth surrounding the contraceptive pill stems from all the way back to the 1960s when the pill was first sold. Initially the pill contained considerably higher levels of oestrogen (nearly 1,000 times more than what most women needed). Oestrogen in such high doses can cause weight gain through increased appetite and fluid retention. Today’s pills contain drastically lower levels of oestrogen and vary from one another in the formulation of hormones. You just need to find the pill that’s most suited to you.
Can I take antibiotics on the contraceptive pill?
Most antibiotics are fine to take with the contraceptive pill. It’s now thought that the only antibiotics that reduce the effectiveness of the contraceptive pill are rifampicin and rifabutin.
Rifampicin and rifabutin are known as “enzyme-inducing” medicines. They speed up the processing of some contraceptive hormones in your blood which reduces the effectiveness of some types of contraception. The types of contraception that may be affected are:
- the combined pill
- the progestogen-only pill (or mini pill)
- an implant
- a patch
- a vaginal ring
If you are on rifampicin or rifabutin for more than 2 months you might want to consider changing to a form of contraception that is unaffected, such as the progesterone injection, an IUD or an IUS. If you’re only taking a short course of rifampicin or rifabutin and you want to stay on your usual contraception you should discuss this with your doctor, as you may need to take it in a slightly different way or use extra protection such as a condom.
What if I vomit or have diarrhoea after taking the pill?
It depends on how long you are sick or have diarrhoea for. If you are sick within 2 hours of taking your pill, it may not have had time to be absorbed into your body and you should take another pill straight away. As long as you are not sick again you will continue to be protected against pregnancy, and you should take your next pill at the usual time the next day. If you want the days of the week to line up with those on the pill packet, you will need to take the extra pill from a spare packet.
If you continue to be sick or if you have severe diarrhoea for more than 24 hours, then the effectiveness of your contraception may be affected. You should count each day with sickness or diarrhoea as a day that you have missed your pill. You should continue to take your pill as normal if possible, but you should also use additional contraception such as condoms. The advice for missed pills depends on what kind of contraceptive pill you are using, but instructions can be found in the leaflet that comes with your contraception, or online at the electronic Medicines Compendium. Alternatively you could ask your doctor for advice.
Can I take the pill back to back without taking a break?
It depends on what kind of pill you are using. If you are on a Progesterone Only Pill (mini pill) then you should be taking pill everyday without taking a break anyway.
If you are taking a combined hormonal pill, then you can start a new packet of pills straight after your last one to delay your period. You can take up to three packs back to back, but since the lining in your womb continues to build up over this time, you might experience breakthrough bleeding, bloating, or stomach pains.
The way you delay your period will depend on which type of combined pill you take.
MONOPHASIC 21 DAY COMBINED PILL:
If you are using a Monophasic 21 day combined pill (a pill that you take for 21 days followed by 7 pill-free days in which you have your period) such as Microgynon or Cilest then you can skip your pill free days and start your new pack straight after you finish the old pack.
EVERY DAY (ED) PILL:
If you are on an Every Day (ED) pill such as Microgynon ED, you would normally take 21 “active” pills, followed by 7 “dummy” pills, during which time you’d have your period. If you are certain which pills are the “dummy” pills, then you can throw these 7 pills away and start straight away on the “active” pills in your new pack. If you’re not sure which are the “dummy” pills, you may be able to find out by carefully reading the leaflet in the pill box, or you can ask a doctor or pharmacist.
Phasic pills contain different mixes of hormone in each pill and must be taken in a specific order for them to be effective. You should check with your pharmacist or doctor which pills are safe to skip.
If you’re not sure what kind of pill you are on, you should ask your GP or pharmacist.
How effective is the pill? How likely am I to get pregnant?
The combined pill and the progesterone only pill are over 99% effective at preventing pregnancy when taken correctly. This means that out of 100 women using the pill, fewer than 1 will become pregnant in one year.
The exact number is actually more like 1 in 1000 women with perfect use of the pill, but with typical use around 8 in 100 women get pregnant in one year.
So if you take the pill as instructed (at around the same time every day) and you are not ill then you are very unlikely to get pregnant. If you do forget to take a pill, then you should take it as soon as you realise, and depending on how late you were in taking it you might need to use and additional form of contraception such as a condom for 7 days.
For more information on the pill and to order contraception online click below.