What is the difference between Plan B and Ella?

​​Plan B and Ella are both emergency contraceptives, but they have some key differences:

  • Active Ingredient: Plan B uses levonorgestrel, a synthetic hormone, while ella uses ulipristal acetate, which works differently to delay ovulation.

  • Time Frame for Use: Plan B is most effective within 72 hours (3 days) of unprotected sex, though it may still work up to 5 days after, but less reliably. Ella can be taken up to 5 days (120 hours) after unprotected sex and has consistent effectiveness throughout that time.

  • Effectiveness: Ella is generally considered a bit more effective than Plan B, especially as more time passes after unprotected sex or during the later part of the cycle.

  • Availability: Plan B is available over the counter without a prescription, whereas ella requires a prescription in the U.S.

In short, Ella tends to work better over a longer window and in more scenarios, while Plan B is more accessible if you need emergency contraception right away.


Ella, like Plan B, is not an abortion pill and will not harm an existing pregnancy. Its role is to prevent ovulation, ensuring there’s no egg available for fertilization. However, because Ella interacts with progesterone, you shouldn’t use it if you're already on hormonal birth control, as it may reduce Ella’s effectiveness.

Efforts to ban emergency contraception, including Ella, stem from the same misconceptions and ideological opposition driving the attacks on Plan B. This is particularly concerning, as Ella provides a vital backup option for preventing unplanned pregnancies in situations where Plan B might not be sufficient.

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What is Ella? (emergency contraceptive)

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Can you use plan B if you’re on birth control but haven't been great at taking your pills every day?