Side Effects of Postinor-2 (P2) oÆn Menstruation
Written By

Joy EmehHuman Anatomist | Health Editor

Key Takeaways:
- One of the most common side effects of Postinor-2, also called P2, is menstrual cycle disturbance. However, this pill does not damage the womb.
- The side effects of Postinor-2 on menstruation include changes in the duration of the period, and heavier menstrual flow. The side effects can last from a few days to several days.
- Postinor 2 can also cause delay in period and irregular menstrual cycle patterns.
- Postinor-2 is not designed to be taken as a regular birth control pill. If you are sexually active, it is best to speak with your doctor about using a regular birth control method, such as hormonal pills and IUDs.
Looking out for a good emergency contraceptive solution to prevent pregnancy after having unprotected sex? Well, you are not alone. Postinor 2 is one of many emergency contraceptives in Nigeria that is affordable out there. However, you need to be aware of its side effects, including effects on menstruation.
Postinor 2 is entirely safe with no fatal or adverse side effects when not abusively used. Contrary to some opinions, Postinor-2 does not cause damage to the womb. Postinor 2 works by delaying ovulation as well as blocking the passage of sperm through the cervix to prevent pregnancy.
In most cases, the side effects of Postinor 2 as shown below last for a few days and things get back to normal, but if the situation persists, you should seek the support of a medical practitioner.Â
Side effects of Postinor 2 on menstrual cycle
Postinor 2 can alter the menstrual cycle, causing missed periods, particularly in people who use it regularly. However, it often doesnât cause serious side effects, even when taken more than once in a cycle.Â
Side effects of Postinor 2 on menstruation include:
- Changes in the length of the menstrual cycle
- Seeing period later (delayed period) or earlier than expected
- Changes in volume of period flow (such as heavier or lighter flow)
- Spottings
âThese changes are often transient, and in the absence of any prior existing condition, periods are likely to return to normal patterns,â said Agbaje Michael (MBBS), Consultant Gynecologist and Obstetrician at Lagoon Hospitals, Lagos, told SemicHealth,
Postinor-2 does not harm a developing fetus; hence, does not induce abortion.
How Postinor-2 works
Postinor-2 is an emergency contraceptive pill (ECP) that contains levonorgestrel. Levonorgestrel belongs to a class of medications called progestins. Progestins work by preventing the release of an egg from the ovary, thereby preventing fertilization.
To explain more on how Postinor-2 works, Dr. Agbaje said âBy virtue of their physiological effects, Postinor-2 also works by altering cervical mucus consistency (thickening it)â.Â
Agbaje added that Postinor-2 may change the endometrial lining (lining of the uterus), making it less receptive to implantation and pregnancy.
However, evidence indicates that Postinor-2 may not reduce the pregnancy rate if taken after ovulation. Also, it cannot prevent implantation if taken after fertilization.
Wondering if Postinor-2 is affordable? Check the price of Postinor-2
How often should you take Postinor-2?
Postinor 2 is an emergency contraceptive and should be taken in situations like contraceptive accidents (e.g., torn condoms and forgotten pills) and coerced sex.Â
It may not cause serious health risks if taken repeatedly; however, Postinor-2 is not designed to be taken as a regular birth control pill. Older studies indicate that Postinor has a failure rate of less than 1 and may only cause relatively few side effects if not more than 4 pills are taken per month.
âPostinor-2 is not advised for frequent use. Patients who plan regular unprotected sex should get other methods,â Agbaje said. Â
When asked how many times in a monthly cycle will be considered as âfrequentâ for the use of Postinor-2, Agbaje said, âIt can be extrapolated that more than once in a cycle is âfrequent.â Itâs advised best use is once in a cycle. Alternative regular methods are advised.â
Should you take Postinor 2 up to three times a month?
It is not healthy to take Postinor 2 three times a month. If you take Postinor 2 multiple times in a month (which is almost similar to one menstrual cycle), you should consider stopping. Instead, speak to your doctor about getting a regular birth control that will be ideal for you.
Read this article on how to take Postinor-2, if you are confused about how to take it.
Other side effects of Postinor 2 (P2)
Postinor-2 has some possible adverse effects. However, Postinor 2 side effects are often not serious and not long-lasting.Â
The most commonly reported side effects of emergency contraceptive pills like Postinor 2 are irregular menstruation and vaginal bleeding disturbances or intermenstrual bleeding. Some people also report side effects like abdominal discomfort and nausea.
As written on the pill's consumer medicine information (CMI) leaflet, side effects of Postinor 2 include:
For people who are sexually active: Read about regular birth control options you can opt for if you are not ready for conception .
When to see a doctor for menstrual cycle issues
Postinor-2 can interfere with your menstrual cycle; however, this is not always the case. Some people experience menstrual cycle issues caused by health conditions that affect the hormones. Health conditions that can affect your periods include polycystic ovarian syndrome (PCOS), pelvic inflammatory diseases, uterine fibroids, and endometriosis.Â
Pregnancy, stress, and lifestyle factors can also contribute to abnormal changes in the menstrual cycle. Always check with your gynecologist if you notice changes, especially repeatedly with your period flow or menstrual cycle.
Your gynecologist will recommend some tests to rule out serious health conditions. If there is a need to start you on a treatment plan, they will discuss this further with you.