Norethindrone acetate (brand name Aygestin®) is a pill that contains the hormone progestin. It is given to stop period bleeding. It works by thinning the lining of the uterus so there is very little of it left to bleed.

This medicine should not be used to prevent pregnancy, so be sure to use birth control if you have sex.

• Follow your health care provider's instructions for dosing. The dose may change over time, but you will take pills every day. 
  
• Take the pills at the same time every day. Setting a reminder on your phone can help you remember.
• If you forget to take a dose, take it as soon as you remember. If you miss more than 2 pills, call your health care provider. Missing doses can cause bleeding that can take a few days to stop.
• Do not stop taking the pills unless you talk to your health care provider first. 

You:

• have spotting or bleeding for more than a week after starting the medicine
• stop bleeding, but then start to spot or bleed again
• have symptoms of anemia (such as pale skin and lips, dizziness, tiredness, or a fast heartbeat) that don't start to get better within a few weeks or that get worse
• you are gaining a lot of weight
• develop acne or had acne but it's gotten worse

Why would someone want to take norethindrone acetate to stop periods? This can help someone who has:

• very heavy or painful periods
• anemia (low red blood cell counts) from heavy periods
• bleeding between periods (including from some types of birth control)
• trouble using pads and tampons because of physical or developmental challenges
• endometriosis (tissue that is like the lining of the uterus but grows outside of the uterus)

Is it safe to stop periods? As long as your health care provider says that hormone medicines are safe for you, it's OK to not have monthly bleeding. If someone stops taking hormone medicines, their periods will start again.

Does norethindrone acetate cause side effects? Most people don't have any side effects. If they do have side effects, such as headaches or nausea, they usually go away within a few weeks. Less often, someone may gain weight, feel very moody, or have acne that gets worse. 

What problems can happen? Norethindrone acetate is generally safe. But if it's taken for a long time, it may cause changes in cholesterol levels. It does not cause infertility (trouble getting pregnant) and does not cause cancer.