Plan B One-Step has a shelf life of about four years from the date of manufacture. The expiration date is printed on the side of the box, listed by month and year. After that date, the pill’s active ingredient may have degraded enough that it can no longer reliably prevent pregnancy.
Where to Find the Expiration Date
The expiration date is printed on the outer packaging, typically on the side of the box. If you’ve removed the pill from its box, the blister pack itself may also carry a date or lot number. Before you need it in an emergency, it’s worth checking this date so you’re not caught off guard. If you keep a pill in a medicine cabinet or travel bag for just-in-case situations, set a reminder to check the date once a year.
What Happens After the Expiration Date
Plan B works by delivering a single high dose of a synthetic hormone that delays or prevents ovulation. Over time, that hormone breaks down. An expired pill isn’t expected to become toxic or cause new side effects, but its potency may have dropped to the point where it no longer delivers enough active ingredient to work effectively.
If you’re in a situation where an expired Plan B is the only option available, taking it is generally better than taking nothing, since some potency may remain. But you shouldn’t count on full protection. Replacing it with a pill that hasn’t expired is always the more reliable choice, and Plan B is available over the counter at most pharmacies without an age restriction.
Storage Conditions That Affect Shelf Life
The FDA-approved labeling specifies storing Plan B at 68°F to 77°F, which is standard room temperature. That means a bathroom medicine cabinet, a bedroom drawer, or a closet are all fine. A car glove compartment is not. In summer, car interiors can easily reach 130°F or higher, which accelerates the breakdown of the active ingredient well before the printed expiration date.
Humidity matters too. The pill is sealed in a blister pack for a reason: moisture exposure can degrade the tablet. If the blister pack is torn, punctured, or has been opened without using the pill, the shelf life is no longer reliable regardless of what the date says. A pill that looks discolored, crumbly, or has an unusual smell should be replaced.
Keeping a Pill on Hand
Because Plan B is most effective within the first 24 hours after unprotected sex and its effectiveness drops with each passing day, many people choose to keep a pill stored at home. This is a reasonable strategy as long as you pay attention to the expiration date and storage conditions. Generic versions containing the same active ingredient are widely available and often cost less, making it easier to replace an expired pill without a significant financial hit.
When buying a pill to stockpile, check the expiration date before purchasing. Pharmacy stock turns over at different rates, and a box that’s been sitting on a shelf for a while may already be closer to expiration than you’d expect. Choosing a box with the furthest-out date gives you the longest window.
How to Dispose of an Expired Pill
The FDA recommends using a drug take-back program if one is available near you. Many pharmacies and community organizations host periodic take-back events, and some pharmacies accept medications year-round. You can also use prepaid drug mail-back envelopes where offered.
If none of those options are accessible, you can throw the pill away at home safely. Remove the tablet from its packaging, mix it with something unappealing like used coffee grounds, dirt, or cat litter, and seal the mixture in a bag or container before placing it in the trash. This keeps it away from children, pets, and anyone who might rummage through discarded items.