Postinor 2 contraceptive, dosage, efficacy and side effects

Keeping up with birth control usage guidelines can be challenging for sexually active people. But, with emergency contraceptives like Postinor-2, you can still be protected on days you mistakenly miss your regular pills.

Image of Postinor 2 tablet

Key takeaways:

  • Postinor 2 is an emergency contraceptive pill that contains 0.75mg of levonorgestrel. It is designed to prevent pregnancy when taken in the correct dosage and within 72 hours after having unprotected sexual intercourse.
  • Because of how it works as well as its side effects, it is not advisable to use Postinor 2 like regular birth control pills or as an abortion pill.

Postinor 2 is a brand-name emergency contraceptive used to prevent pregnancy after sexual intercourse if used in the correct dosage. It is also called Plan B or morning-after pill.

Postinor 2 contains 0.75mg of levonorgestrel as an active agent. Unlike its one-pill version (Postinor-1), Postinor 2 contains two pills, both of which are best taken within 72 hours of sexual intercourse. The longer the time when it is taken after sex, the less effective it is.

As an emergency contraceptive pill, Postinor 2 is designed to be taken only after sex and not before. It is one of a last resort on days you missed your regular birth control pills or noticed your condom broke during sex.

Postinor 2 is readily available at regular pharmaceutical shops across Nigeria, with price ranging from N800–N3,500.

Many mistake emergency contraceptives like Postinor 2 for abortion pills. Postinor 2 is only effective before implantation (pregnancy) due to the nature of how it works as discussed below.

How Postinor 2 works

Postinor 2 when consumed in the right dosage, works mainly by preventing ovulation (the release of a mature egg from the ovary). When ovulation does not occur, there won’t be fertilization and, ultimately, no pregnancy.

Secondly, Postinor 2 blocks passage of sperm cells into the uterus by making the mucus secreted in the cervix thicker.

The efficacy of Postinor 2 is down to Levonorgestrel, a progestin and as such, its side effects are down to the side effects of progesterone in women.

Side effects of Postinor 2

Among the side effects of Postinor 2 are:

  • Spotting within 2-3 days of taking the medication
  • Breast pain or tenderness
  • Headache
  • Fatigue
  • Dizziness

Dosage and how to take Postinor 2

Postinor 2 contains two tablets or pills. Each of the two pills contains 0.75 mg of levonorgestrel and other inactive ingredients like magnesium stearate, silica colloidal anhydrous, lactose monohydrate, and maize starch.

Correct dosage and consumption of Postinor 2 involve taking one of the pills within 72 hours after sexual intercourse and then taking the second pill 12 hours after taking the first one.


The 2 postinor 2 tablets should not be consumed at once. The second tablet must be consumed 12 hours after taking the first one

Clinicians advise against taking more than 4 tablets of Postinor 2 in one menstrual cycle - It can lead to heavier or lighter bleeding, or disrupt the cycle.

If you have unprotected sex multiple times in one menstrual cycle, it is best to seek medical advice from a healthcare provider regarding the best contraceptive method for you.

When to take and not take postinor 2

Postinor 2 should be primarily taken within 3 days after having an unprotected sex. The earlier it is taken after sex, the higher the chances of it preventing pregnancy. As stated earlier, Postinor 2 is not an abortion pill - it should not be taken post-pregnancy.

In addition, It is safe to take Postinor 2 during menstrual periods. However, you should not take Postinor 2 if your period is late until you confirm that you are not pregnant.

Below is a list of when Postinor 2 can be taken:

  1. Your IUD fell out.
  2. Your condom slipped off or tore during sex.
  3. You experience sexual assault like rape.
  4. You skipped taking your regular birth control pill.
  5. You had unplanned sex during your fertile period.
  6. You relied on the unreliable withdrawal method during sex.

In contrast, Postinor 2 should not be taken if:

  • You have used it before in the same cycle (not advisable).
  • You are pregnant.
  • You are experiencing vaginal bleeding.
  • It has expired, or the medication packaging has been tampered with.
  • It is more than 72 hours or 3 days since the sex took place.

Success rate of Postinor 2

You are probably wondering if you can still get pregnant after taking Postinor 2 within 72 hours after sex. The answer is, yes. Although Postinor 2 decreases the chances of getting pregnant, there is still some chance that a person can get pregnant after taking it.

The efficiency of Postinor 2 in the prevention of pregnancy is rated at 57-93%. There is little chance of getting pregnant even after taking Postinor 2. The closer the time after sex that it is taken, the better your chances of not getting pregnant.

If you suspect being pregnant even after taking the pill, take a home pregnancy test or contact your healthcare provider.

Postinor 2 taken 4 days after sex

Most emergency birth control pills have a 5-day working window. However, it is not proven that Postinor-2 can be effective if taken beyond three days (72 hours) after sex.

When to see your doctor

Postinor 2, as shown in this article, is effective and safe to use, provided it is taken as instructed. However, it is important to speak to a healthcare provider if you experience severe symptoms like intense stomach pain and heavy or extended bleeding after using Postinor 2.

If you are sexually active but do not want to get pregnant, speak to a gynecologist or healthcare practitioner in related fields for contraceptive options that are best suited for your use case.

Frequently Asked Questions (FAQs)

How long does Postinor 2 last in the body?

Postinor 2 has a half-life of about 24-29 hours, and it takes about five half-lives for a medication to be cleared from the body. Multiplying one half-life by five means, Postinor 2 can last in the body for 120–145 hours (i.e., about 5–6 days). After this period, almost all of the medication must have been cleared from the body.

Can I take Postinor 2 at once?

No, Postinor 2 is not designed to be taken at once. Health experts recommend taking one pill soon after sex and the second pill after 12 hours.

Can I get pregnant after taking Postinor 2?

Yes, it is possible to get pregnant after taking Postinor 2. This can happen if you don't take the medication within 24 hours after unprotected sexual intercourse, if you don't take the medication as instructed, if you vomit within two hours of taking the pill (without taking another one), or if you are already ovulating at the point of taking it.

How effective is Postinor 2?

Just like other Plan B morning-after pills, Postinor 2 is up to 89% effective for preventing pregnancy when taken within three days after unprotected sex. But keep in mind that there are factors that can affect how effective the pill is, including your BMI and how soon you ingest it after sex.

Is Postinor 2 good for breastfeeding mothers?

Evidence suggests that it is okay for breastfeeding mothers to take Postinor 2, as its active ingredient (levonorgestrel) does not adversely affect the growth of the infants, breast milk composition, or milk supply. Still, non-hormonal birth control methods like IUDs and condoms are often preferred over hormonal methods like pills for lactating mothers.