The most commonly prescribed pill to delay a period is norethisterone, a synthetic form of progesterone. If you’re already on a combined birth control pill, you can also skip your placebo week and start a new pack to push your period back. Both approaches work by keeping hormone levels steady so the uterine lining stays in place instead of shedding.
How Norethisterone Works
Norethisterone is a progestogen tablet prescribed specifically to postpone menstruation. You take one tablet three times a day (a total of 15 mg daily), starting three days before your period is expected. As long as you keep taking it, your period won’t arrive. Once you stop, bleeding typically starts within two to three days.
You can take norethisterone for up to three to four weeks if needed, though most people use it for a week or two to cover a holiday, wedding, or athletic event. It is not a contraceptive at this dose, so if you need pregnancy protection, you’ll still need to use a separate method.
In the UK, norethisterone is a prescription-only medication with “postponement of menstruation” listed as an approved use. In the US, the same compound (called norethindrone) is available by prescription as well, though it’s more commonly prescribed for conditions like endometriosis or irregular bleeding rather than specifically marketed for period delay. Your doctor or an online prescriber can write the prescription in either case.
Using Birth Control Pills to Skip a Period
If you already take a combined hormonal birth control pill (one that contains both estrogen and progestin), you have a built-in option. Instead of taking the inactive placebo pills at the end of your pack, skip them and start a new pack of active pills right away. The steady hormone supply prevents the withdrawal bleed you’d normally get during the placebo week.
Some pill regimens are designed around this principle. Extended-cycle packs provide 84 days of active pills followed by one week of low-dose or inactive pills, so you only bleed about once every three months. Continuous-use regimens go even further, supplying active hormones for a year or longer with no planned breaks.
If you’re new to skipping the placebo week, breakthrough bleeding or spotting is common in the first few cycles. This usually spaces out and stops over time. If it becomes heavy or lasts more than seven days straight, contact your healthcare provider. Breakthrough bleeding doesn’t mean the contraception has failed.
Timing Matters
Planning ahead is essential. For norethisterone, you need to start the tablets three days before your period is due. That means you need to have a reasonable idea of when your cycle will begin. If your periods are irregular, predicting the right start date can be tricky, and starting too late may mean the medication doesn’t fully prevent bleeding.
For the combined pill method, you simply continue taking active pills when you’d normally switch to placebos. No special lead time is required beyond what your regular pill schedule already provides. If you’re not currently on the pill and want to use this approach, you’d need to start the pill at least one full cycle before the event you’re planning around.
Common Side Effects
Norethisterone can cause side effects that overlap with typical hormonal symptoms. The most frequently reported include:
- Irregular spotting or breakthrough bleeding
- Breast tenderness or swelling
- Nausea or bloating
- Weight fluctuations
- Acne or changes in skin
- Trouble sleeping
- Hair thinning or increased facial hair growth
Less common but more serious effects include mood swings and depression. These are worth watching for, especially if you have a history of mood-related conditions. For most people using the pill short-term (one to two weeks), side effects are mild and resolve after stopping.
Skipping the placebo week on combined pills generally doesn’t introduce new side effects beyond what you already experience on your regular pill. The main difference is breakthrough spotting, which is more likely the longer you go without a break.
Who Should Avoid Period Delay Pills
Because norethisterone is a hormonal medication, it isn’t suitable for everyone. People with a history of blood clots, certain hormone-sensitive cancers, or severe liver disease are typically advised against it. If you have migraines with aura, a history of stroke, or uncontrolled high blood pressure, your prescriber will weigh those risks before writing a prescription.
The same cautions apply to extended use of combined birth control pills, which carry their own clot-related risks due to the estrogen component. Your prescriber will review your medical history before recommending either approach.
What Happens After You Stop
Once you finish your course of norethisterone, your period will arrive within two to three days. The bleed is generally normal in flow and duration, though some people notice it’s slightly heavier or lighter than usual for that first cycle. Your regular cycle should return to its normal pattern after that.
If you’ve been running combined pill packs back to back, your withdrawal bleed will start during the next placebo week you take, or within a few days of stopping the pills entirely. The longer you’ve been skipping breaks, the more likely you are to have some irregular spotting as your body readjusts.