Progestin only pills (POP)
- These pills have only progesterone (no estrogen).
- These are often prescribed if a person is:
- Sensitive to estrogen
- Breastfeeding
- Has a medical condition that makes estrogen use unsafe
- Each pill in the pack is the same. It does not have placebo pills. They do not cause you to have a period during a set week.
- POPs prevent pregnancy by making the cervical mucus thicker so sperm cannot get inside the uterus. They also lessen ovulation (you do not release an egg).
When to start the pill
The POP can be started anytime if you are certain you are not pregnant. You do not need to wait for the next menstrual cycle. There is no need to wait until the Sunday after a period either.
Postpartum
Start taking this pill right away. POPs do not lower milk supply.
Miscarriage
POPs can be started within the first 7 days after first-trimester or second-trimester pregnancy loss.
When does the pill start working?
- If it is started within the first 5 days of a regular period, it will work right away.
- If it is started any other time during a menstrual cycle:
- Do not have sex or be sure to use another birth control method (such as condoms) for 7 days.
- If switching from an IUD, do not have sex or use a back-up birth control method for 7 days.
- You do not need to use a back-up method if you switch from a non-IUD method (such as pill, patch, ring, or shot) to a POP.
How to take the pill
- You must take the POP at the same time each day.
- Taking a pill late or missing a pill will increase the chance for pregnancy.
Missed or late POPs
If you are late taking a POP
- Take it as soon as you remember.
- Use a back-up method (such as condoms) or do not have sex for 7 days.
If you have missed 1 or more POPs
- Take it as soon as you remember.
- Use a back-up method (such as condoms) or do not have sex for 7 days.
Think about taking emergency contraception if you missed a pill and had unprotected sex in the past 5 days.
Side effects
Period changes
- It is normal to have regular periods, irregular periods, or no periods while taking a POP.
- Call your health care provider if your flow is heavy (more than 1 pad per hour).
Weight gain
There is no evidence POPs cause weight gain.