Take Action, a levonorgestrel emergency contraceptive pill, can reduce your risk of pregnancy by up to 91% when taken immediately after unprotected sex. In clinical studies, the overall pregnancy rate among women who used levonorgestrel emergency contraception ranged from 1.2% to 2.1%. Those numbers sound reassuring, but real-world effectiveness depends heavily on timing, body weight, and where you are in your cycle.
How Take Action Works
Take Action contains 1.5 mg of levonorgestrel, the same active ingredient found in Plan B. It works by temporarily stopping your ovary from releasing an egg. Think of it as pulling the emergency brake on ovulation. If your body has already released an egg, the pill won’t be effective. This is the single most important thing to understand: Take Action prevents pregnancy before ovulation, not after.
This also means the pill does not end an existing pregnancy. If a fertilized egg has already implanted, Take Action has no effect.
Timing Changes Everything
The sooner you take it, the better it works. Taking levonorgestrel immediately after sex could reduce pregnancy risk by about 91%. But most people don’t take it immediately. When researchers accounted for the realistic delays people experience (getting to a pharmacy, deciding what to do), the average effectiveness dropped to somewhere between 49% and 67%.
Take Action works best within the first 72 hours (3 days) after unprotected sex. You can technically take it up to 5 days (120 hours) afterward, but effectiveness drops noticeably after that 72-hour window. Every hour matters. If you’re considering whether to take it now or in the morning, take it now.
Body Weight and Effectiveness
This is where Take Action has a significant limitation. Clinical data shows a steep increase in pregnancy risk starting around 154 to 165 pounds (70 to 75 kg). At body weights above roughly 176 pounds (80 kg), the pregnancy rate climbed to about 6%, which is close to the rate you’d expect without any emergency contraception at all.
The pattern holds when measured by BMI, too. Pregnancy rates began rising sharply at a BMI of 26 and plateaued around a BMI of 31 to 32 at a pregnancy risk near 5%. Planned Parenthood is direct about this: if you weigh more than 165 pounds, levonorgestrel morning-after pills may not work.
If your weight falls in this range, a prescription pill called ella (ulipristal acetate) is a more effective option, though it also has limits above 195 pounds. A copper IUD, placed within 5 days, is the most effective emergency contraception regardless of body weight.
Take Action vs. Ella
Ella is the most effective morning-after pill available, outperforming Take Action across every time window. The gap is especially noticeable in two situations: when more than 72 hours have passed and when body weight is above 165 pounds. Ella also works closer to the moment of ovulation than levonorgestrel pills do, giving it a wider biological window of effectiveness.
The tradeoff is access. Take Action is available over the counter at most pharmacies without a prescription or age restriction. Ella requires a prescription. If you’re within 24 hours and under 165 pounds, Take Action is a practical, effective choice. Outside those conditions, ella or a copper IUD is worth the extra effort.
Medications That Reduce Effectiveness
Certain drugs speed up how quickly your liver breaks down levonorgestrel, potentially lowering the amount in your bloodstream enough to reduce its contraceptive effect. The main categories include:
- Epilepsy medications such as phenytoin, carbamazepine, and primidone
- Tuberculosis medications such as rifampicin and rifabutin
- HIV medications such as ritonavir and efavirenz
- Antifungal medications such as griseofulvin
- St. John’s wort, a common herbal supplement
If you take any of these, the standard 1.5 mg dose may not provide adequate protection. Some guidelines suggest doubling the dose to 3 mg, but a copper IUD or ella may be better options to discuss with a provider.
Common Side Effects
Most side effects are mild and resolve within a day or two. You may experience nausea, headache, dizziness, fatigue, breast tenderness, or cramping. Some people have light spotting or notice their next period arrives earlier or later than expected. Vomiting is possible. If you throw up within two hours of taking the pill, you may need a second dose since the medication may not have been fully absorbed.
Take Action does not affect your future fertility and is not associated with long-term side effects. It’s a single dose, and once it clears your system, your normal cycle resumes, though that first period after taking it can be somewhat unpredictable in timing or flow.
What Realistic Effectiveness Looks Like
The “up to 95%” figure you’ll see on packaging and websites represents the best-case scenario: taking the pill very quickly, being well under the weight threshold, and not having ovulated yet. For most people in real-world conditions, effectiveness is lower. The 1.2% to 2.1% pregnancy rate from clinical studies reflects a population that generally took the pill within the recommended window, but individual results vary widely based on the factors above.
The most honest way to think about Take Action is as a meaningful reduction in risk, not a guarantee. If you took it within a few hours, weigh under 165 pounds, and aren’t on interacting medications, you’ve significantly lowered your chances of pregnancy. If one or more of those conditions doesn’t apply, the protection is less reliable, and alternatives like ella or a copper IUD offer stronger coverage.