Ideally you would take these medications 3 days before your period is due. You can take them for a maximum of 20 days. When you stop taking the tablets it takes roughly 2 days for the period to start.

The online consultation will check whether or not it is safe for you to take these medications. It is advised that they are not used frequently. There is a concern that they increase the risk of blood clots which can be very serious and cause a stroke or PE (blood clot on the lungs).

Both medications are usually reliable at delaying periods. Provera has a lower risk of complications such as blood clots. It is usually the preferred choice for women who have a higher risk of problems, e.g., those who are overweight, smoke, are over the age of 35 or have raised blood pressure. However, even though Provera is widely used to delay periods, you should be aware that it doesn't officially have a license for this. That means, when it was first studied to see if it was safe, it was being used to treat something different. It passed the studies, so it is licensed to treat other things. And it can be used to delay periods, but because this isn't what it was originally studied for, it's use in delaying periods is called 'off-label' or 'unlicensed'. Norethisterone is licensed, but we know that the risk of things like blood clots is higher with it.

Generally side effects are not experienced but if they are the more likely complaints are:
Bloating
Breast Tenderness
Headache
Nausea

Less common side effects include:
Allergic reaction
Dizziness
Wheezing
Please see the patient information leaflet for a full list of possible side effects