Which is better Postinor 2 or Postinor 1? Understanding the Differences

October 10, 2025 •

4 min read

While both Postinor-1 and Postinor-2 contain the same active ingredient, levonorgestrel, and work primarily by delaying or preventing ovulation, their key difference lies in the formulation and administration. Choosing which is better, Postinor 2 or Postinor 1, depends heavily on convenience and local availability, as the single-dose Postinor-1 is often considered the more modern option, especially when taken as soon as possible.

Quick Summary

This article provides a detailed comparison of Postinor 1 and Postinor 2, covering their formulations, administration schedules, and overall effectiveness. The content clarifies how both leverage levonorgestrel for emergency contraception, explaining why the single-dose format of Postinor-1 offers higher convenience and potentially greater efficacy over the older split-dose regimen of Postinor-2. It outlines their mechanisms, side effects, and important considerations for users.

Key Points

Formulation Difference: Postinor-1 is a single tablet, while Postinor-2 is a two-tablet pack.
Convenience: Postinor-1 is more convenient, requiring only one dose and reducing the risk of forgetting a second dose.
Equivalent Efficacy: Effectiveness is comparable when both Postinor-2 tablets are taken simultaneously, mirroring the Postinor-1 method.
Time-Sensitive Action: Both are most effective when taken as soon as possible after unprotected sexual intercourse, with reduced efficacy over time.
Mechanism of Action: Both function by delaying or preventing ovulation, thickening cervical mucus, and hindering fertilization.
Common Side Effects: Both versions share side effects like nausea, headache, dizziness, and menstrual irregularities.
Alternative Dosing: If only Postinor-2 is available, taking both tablets at once is an effective alternative to Postinor-1.
Availability: Postinor-1 is becoming the more common and standard option in many regions.

Postinor 1 vs. Postinor 2: A Comprehensive Comparison

Emergency contraception is a critical safety net for preventing unintended pregnancy after unprotected sexual intercourse or contraceptive failure. The Postinor brand offers two primary formulations containing the active ingredient levonorgestrel: Postinor-1 and Postinor-2. While both serve the same purpose, there are notable differences in their administration and, consequently, their perceived effectiveness and convenience. Deciding which is better, Postinor 2 or Postinor 1, requires understanding these distinctions, particularly concerning how the active ingredient is delivered and modern recommendations.

The Fundamental Difference: Formulation and Convenience

The most significant and immediate difference between Postinor-1 and Postinor-2 is the dosing regimen. Postinor-1 is a single-tablet solution, containing the entire recommended amount of levonorgestrel in one pill. This offers a major advantage in terms of simplicity and user compliance. The user only needs to remember to take one pill, as soon as possible after unprotected sex.

In contrast, Postinor-2 comes with two tablets, each containing a portion of the total recommended amount of levonorgestrel. The traditional instruction for this regimen is to take the second tablet after a specific time interval following the first. This split-dose approach introduces the risk of forgetting or mistiming the second dose, which could reduce effectiveness. While some guidelines suggest taking both Postinor-2 tablets at the same time for equivalent effectiveness to Postinor-1, the single-dose product eliminates this confusion entirely. The move towards single-dose products like Postinor-1 reflects a broader trend in pharmacology toward more user-friendly and reliable dosing schedules for emergency contraception.

Comparing Effectiveness and Mechanism of Action

Both Postinor-1 and Postinor-2 operate on the same principle, relying on the high dose of the synthetic progestogen levonorgestrel to prevent pregnancy. The primary mechanism is the inhibition or delay of ovulation. By delaying the release of an egg, the medication ensures that no egg is available for fertilization during the time sperm may be present in the reproductive tract.

The effectiveness of levonorgestrel-based emergency contraception is highly time-sensitive. It is most effective when taken as soon as possible after unprotected intercourse and its efficacy decreases over time.

Studies have shown that receiving the total amount in a single administration is either as effective as or more effective than the split-dose regimen, particularly when the single dose is taken early. This is because the single, higher concentration ensures that the drug is delivered quickly and completely to prevent the hormonal cascade leading to ovulation. The split-dose method, while eventually delivering the same total amount of medication, may be less effective if the second dose is forgotten or delayed, or if it is not taken at all.

Side Effects and Tolerance

The side effect profiles of Postinor-1 and Postinor-2 are largely similar, as they contain the same active ingredient. Common side effects can include:

Nausea and vomiting
Fatigue
Headache
Dizziness
Breast tenderness
Abdominal pain or cramps
Changes in menstrual bleeding patterns

Nausea and vomiting are among the most frequently reported side effects. Some studies, however, suggest that the nausea and vomiting rates might be lower with the single-dose formulation compared to the older, split-dose method. Regardless of which version is taken, if vomiting occurs within two hours of taking a dose, it is crucial to consult a pharmacist or doctor, as another tablet may be needed.

Postinor-1 vs. Postinor-2: A Comparison Table


Feature	Postinor-1	Postinor-2
Formulation	Single tablet	Two tablets
Administration	One tablet, taken as soon as possible after unprotected sex.	Two tablets, with the second taken after a specific time interval following the first. Some guidelines allow taking both at once.
Convenience	High. Single-dose is simple and easy to remember.	Lower. Requires remembering a second dose, increasing risk of non-compliance.
Effectiveness	Considered slightly more reliable due to guaranteed single, complete absorption.	Effective, but depends on adherence to the two-dose schedule. Taking both at once is considered equally effective to Postinor-1.
Availability	Often the standard, modern version available in many regions.	Older formulation, still available in some markets, but becoming less common.

Is Postinor-1 always the best choice?

For most people, Postinor-1 is the preferred option. Its single-dose format simplifies the process and eliminates the risk of forgetting the second tablet, which is a common error with the older Postinor-2 regimen. This simplification translates to a higher likelihood of correct use and, therefore, maximum effectiveness. The concentration of the single dose ensures a quicker absorption of the active ingredient, making it particularly valuable when time is of the essence.

However, it's essential to note that both versions contain the same total amount of levonorgestrel, and when the two tablets of Postinor-2 are taken together at the same time, their effectiveness is considered equivalent to that of Postinor-1. In situations where Postinor-1 is unavailable but Postinor-2 is, taking both tablets of Postinor-2 together is a viable and effective alternative, provided it is done as soon as possible.

Conclusion

In the debate of which is better, Postinor 2 or Postinor 1, the single-dose Postinor-1 emerges as a superior and more user-friendly option for emergency contraception. Its simplified administration reduces the chance of user error and ensures that the medicine is taken correctly and promptly, which is a critical factor for efficacy. While both formulations contain the same total amount of levonorgestrel and can be equally effective if taken correctly, the modern standard favors the ease and convenience of a single dose. Regardless of the version used, speed is the most important factor—the sooner the pill is taken, the more effective it will be. Anyone needing emergency contraception should seek the most readily available and convenient option and take it without delay.

Disclaimer: This information is for informational purposes only and does not constitute medical advice. For professional medical guidance on emergency contraception, consult a healthcare provider or a pharmacist.

Frequently Asked Questions

The total dose of the active ingredient, levonorgestrel, is the same in both formulations when taken correctly. However, Postinor-1 is considered more reliable because its single-dose regimen removes the risk of forgetting the second dose of Postinor-2, which is crucial for maximum efficacy.

The main difference is the formulation and administration. Postinor-1 is a single tablet, while Postinor-2 comes with two tablets, traditionally taken with a time interval between them.

Yes, taking both Postinor-2 tablets together at the same time is a common and acceptable practice that makes it functionally equivalent to Postinor-1. This ensures you receive the full dosage at once, which is a more convenient and often more reliable method.

If you vomit within two hours of taking either Postinor-1 or a dose of Postinor-2, the medication may not have been fully absorbed. You should contact a pharmacist or doctor immediately, as a repeat dose may be necessary.

For both Postinor-1 and Postinor-2, the sooner you take the medication, the more effective it will be. It is most effective when taken within the first 24 hours and can be taken up to 72 hours (3 days) after unprotected sexual intercourse.

Yes, because both contain the same active ingredient, levonorgestrel, they have similar side effect profiles, which can include nausea, headache, fatigue, and menstrual irregularities.

The effectiveness of Postinor significantly decreases after 72 hours and is not recommended beyond this time. For emergency contraception beyond this window, alternative options like a copper IUD are more effective.

No, Postinor is for emergency use only and should not be used as a regular method of contraception. It is much less effective than regular, planned methods like hormonal pills or IUDs.