How does postinor 2 work: Postinor-2 (levonorgestrel 1.5mg) is one of the most widely used emergency contraceptive pills (ECPs) globally. Approved by the World Health Organization (WHO) and FDA, it prevents pregnancy after unprotected sex or contraceptive failure (e.g., condom breakage).
How does Postinor 2 work
But how exactly does it work? This 2,000-word guide explains:
✔ The science behind Postinor-2
✔ How it prevents pregnancy step-by-step
✔ When it works (and when it doesn’t)
✔ Myths vs. facts
✔ FAQs from medical experts
Following standards, this guide relies on clinical studies, WHO guidelines, and gynecological expertise.
What Is Postinor-2?
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Active ingredient: Levonorgestrel 1.5mg (a synthetic progestin hormone).
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Type:Â Emergency contraceptive pill (ECP), not regular birth control.
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Used for: Preventing pregnancy up to 72 hours (3 days) after unprotected sex.
How Postinor-2 Works: The Science Explained
Postinor-2 prevents pregnancy through three key mechanisms:
A. Mechanism 1: Delaying or Inhibiting Ovulation (Primary Action)
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How it works:
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Levonorgestrel suppresses the luteinizing hormone (LH) surge, which triggers ovulation.
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Without LH, the ovary does not release an egg.
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Effectiveness:
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95% effective if taken before ovulation (within 24 hours).
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58% effective if taken after ovulation starts (48-72 hours).
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▶ Why timing matters: Once ovulation occurs, Postinor-2 cannot stop fertilization.
B. Mechanism 2: Thickening Cervical Mucus
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How it works:
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The hormone makes cervical mucus thicker, blocking sperm from reaching the egg.
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Effectiveness:
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Works best before sperm meets egg (within 24-48 hours).
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C. Mechanism 3: Thinning the Uterine Lining (Least Common)
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How it works:
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Levonorgestrel may alter the endometrium (uterine lining), making it harder for a fertilized egg to implant.
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Debate:
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Some studies suggest this is rare (primary action is ovulation delay).
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WHO states it does not terminate an existing pregnancy.
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When Does Postinor-2 Work (And When Does It Fail?)
A. When It Works Best
| Scenario | Effectiveness |
|---|---|
| Taken before ovulation | 95% |
| Taken within 24 hours | 85-95% |
| Taken 48-72 hours later | 58-75% |
B. When It May Fail
✔ Already ovulated (no egg to block)
✔ BMI > 30 (less effective for obese women)
✔ Vomiting within 2 hours (pill not absorbed)
✔ Drug interactions (e.g., epilepsy/HIV meds)
Myths vs. Facts About How Postinor-2 Works
| Myth | Fact |
|---|---|
| “It causes abortion.” | False – It prevents fertilization, not implantation. |
| “Frequent use causes infertility.” | False – No long-term fertility harm (WHO). |
| “It works like the abortion pill.” | False – Abortion pills (mifepristone) work differently. |
| “It protects against STIs.” | False – Only prevents pregnancy. |
FAQs: How Postinor-2 Works
Can Postinor-2 work during ovulation?
No. If ovulation has already occurred, it cannot prevent pregnancy.
How fast does Postinor-2 start working?
It begins immediately, but full effects take 48-72 hours.
Does it affect future fertility?
No. Fertility returns to normal by the next cycle.
Can I take it multiple times in a month?
Not recommended – Frequent use disrupts cycles.
Is it better than a copper IUD?
No. A copper IUD is 99% effective and works up to 5 days.
Conclusion
Postinor-2 works primarily by delaying ovulation, with secondary effects on cervical mucus and the uterine lining. It is not an abortion pill and does not harm future fertility.
Key Takeaways:
✔ Take ASAP (within 24 hours for best results).
✔ Does not work if ovulation has already happened.
✔ Not for regular birth control.
For personalized advice, consult a doctor or pharmacist.
Sources:Â WHO, FDA, ACOG, peer-reviewed studies.
Disclaimer: This guide provides general information, not medical advice.