Which things could make my contraceptive pill less effective?

Missed Pills

If you miss a pill or are late taking one at any time, there is a very real risk you could become pregnant if you don’t follow instructions about what to do very carefully.

There are strict rules about what you should do if you miss a pill. As long as you follow these instructions, you have a very low risk of becoming pregnant. The greatest risk of pregnancy is if you miss a pill at the beginning or very end of a 21 day cycle.

You can find the instructions about what you should do if you miss a pill and when you should use additional contraceptive protection to avoid pregnancy in your Product Information Leaflet, or you can read them on our Missed pills page.

If I am sick or ill, will my pill work properly?

If you become sick and suffer from vomiting or diarrhoea, it can reduce the effectiveness of your pill and you may need to take additional precautions.

If I take other medicines, will my pill be affected?

Some medications can reduce the effectiveness of the pill, so it is very important that you tell your doctor or pharmacist if you are taking or have recently taken any medicines, ‘over the counter medicines’, herbal products, or supplements before you start taking Levest.

If you are already taking Levest, ask your doctor or pharmacist if any new medicine or supplement could reduce the effectiveness of your contraception before you start taking it.

Examples of medicines that can affect the effectiveness of your contraceptive pill include antibiotics, antifungal medicines, cholesterol lowering drugs, antidiabetic medicines, antidepressants, antacids as well as some health food supplements and herbal remedies such as St. Johns Wort. 

If you need to take another medication that reduces the effectiveness of Levest, you may need to take additional contraceptive measures to ensure you don’t become pregnant.

What if I am travelling abroad? Will the time difference matter?

When travelling abroad, it should not be a problem to continue taking your pill at your normal time of day, so long as the time difference is no greater than 12 hours. Most European destinations only have a small time difference, and should not present you with any problems.

However, if you are going on a long haul flight, for example to destinations in Asia or the America’s, there may be a large time difference of more than 12 hours, which could present a problem. Don’t worry! Simply follow the instructions below.

    • Take your pill at your normal time the day before you leave.
    • Take your next pill 12 hours later on the day you leave.
    • Take your next pill 24 hours later at your ‘normal’ time of day when you arrive at your destination.

However, don’t forget to take some additional contraceptive protection on holiday with you. Lots of people can get ‘travellers tummy’ with diarrhoea and vomiting when they go abroad, and this could reduce the effectiveness of your pill. Having additional protection to hand can help to prevent an unwanted pregnancy.

If you have any concerns or are confused by these travelling recommendations, talk to your healthcare provider so that you are clear about what you should do.