Does Plan B Expire? What You Need to Know

TL;DR

• Plan B has a shelf life of about 4 years from manufacture date; expiration date is printed on box.
• After expiration, levonorgestrel loses potency and may not effectively prevent pregnancy.
• If your Plan B is expired, get a new one from any pharmacy; it is available over counter with no prescription, ID, or age requirement.

Where to Find Expiration Date

The expiration date is printed on outer packaging of Plan B box. It is usually on side or bottom. If you removed pill from its box, date may also appear on blister pack holding tablet, but box is most reliable place to check.

The date is formatted as a month and year. If your Plan B says "EXP 08/2027," it means manufacturer guarantees the pill's full potency through end of August 2027. After that date, levonorgestrel may begin to degrade, and medication's ability to prevent pregnancy is no longer assured.

If you cannot find expiration date or packaging is damaged to point where you cannot read it, treat pill as potentially expired and replace it.

What Happens After Plan B Expires?

The active ingredient in Plan B is levonorgestrel, a synthetic progestin hormone. Like all medications, levonorgestrel can break down over time. The FDA requires pharmaceutical companies to guarantee that a drug maintains its stated potency and purity through expiration date when stored properly. After that date, guarantee no longer applies.

This does not mean pill becomes toxic or dangerous after it expires. Taking an expired Plan B is unlikely to harm you. The concern is effectiveness. If levonorgestrel has degraded enough, pill may not deliver a sufficient dose to reliably prevent ovulation, which is how it works. And with emergency contraception, where effectiveness is time-sensitive and there is no easy way to know if it worked until your next period, relying on a potentially weakened pill is a risk most people should not take.

There is no specific research quantifying exactly how much potency Plan B loses at various points after expiration. The FDA's drug expiration date study (known as Shelf Life Extension Program) has found that many medications retain potency well beyond their labeled expiration dates. But this data is limited to specific drugs tested under controlled conditions, and results are not universally applicable to all medications. For something as important as preventing an unintended pregnancy, using an unexpired pill is safest choice.

FDA Information on Drug Expiration Dates

How to Store Plan B So It Lasts

Proper storage helps ensure Plan B stays effective through its full shelf life. The guidelines are simple.

Keep it in its original packaging. The box and blister pack protect tablet from moisture, light, and physical damage.

Store it at room temperature. The recommended range is between 68 and 77 degrees Fahrenheit (20 to 25 degrees Celsius). Avoid extremes of heat or cold.

Keep it in a dry place. Bathrooms might seem like a logical spot, but humidity from showers can affect medication over time. A bedroom drawer, a nightstand, or a cool closet shelf are all better options.

Avoid direct sunlight. UV exposure can accelerate breakdown of active ingredients. A drawer or cabinet keeps pill shielded.

Do not store it in your car. Temperatures inside a parked car can swing dramatically, from extreme heat in summer to below freezing in winter. Both can damage medication.

If you follow these basic storage practices, Plan B should stay effective right up to its printed expiration date.

Should You Buy Plan B in Advance?

Absolutely. One of best things about Plan B is that it is available over counter at virtually every pharmacy in United States. No prescription is needed. No ID is required. There is no age restriction. You can walk in, buy it, and keep it on hand for whenever you or someone you know might need it.

Buying it in advance takes stress out of an already stressful situation. If you need emergency contraception at 2 AM on a Sunday, you do not want to be driving around looking for an open pharmacy. Having a pill ready in your drawer means you can take it immediately, which is when it works best.

Plan B is most effective within first 24 hours after unprotected sex, reducing risk of pregnancy by about 95%. Between 24 and 48 hours, effectiveness drops to about 85%. Between 48 and 72 hours, it drops further. It can still be used up to 5 days after, but effectiveness decreases significantly with each passing day. The speed factor is exactly why having an unexpired pill already at home matters so much.

When you buy Plan B in advance, write expiration date somewhere visible, like on your phone calendar with a reminder a few weeks before it expires. That way, you can replace it before it goes out of date.

What If Your Plan B Is Already Expired?

If you find yourself needing emergency contraception and only Plan B you have is expired, here is what to do.

If it is only recently expired (within a few weeks to a couple of months), taking it is better than taking nothing. Levonorgestrel does not suddenly stop working day after expiration date. There is likely still some potency remaining. However, you cannot know how much, so replace it with a new pill as soon as possible if you can get to a pharmacy quickly.

If it has been expired for six months or longer, reduction in potency becomes more unpredictable. In this situation, getting a new, unexpired pill from a pharmacy should be your priority. Plan B is widely available and typically costs between $30 and $50 at most retail pharmacies.

If you cannot get Plan B, there is another emergency contraceptive option called ella (ulipristal acetate), which is available by prescription and is effective up to 5 days (120 hours) after unprotected sex. It has a shelf life of about 3 years. A copper IUD, placed by a healthcare provider within 5 days, is most effective form of emergency contraception available and also provides ongoing birth control for up to 10 years.

If you are trying to understand how levonorgestrel works and what medications may interact with it, this guide covers key details: Levonorgestrel Interactions

Does Weight Affect How Well Plan B Works?

This is an important consideration that does not get enough attention. Research suggests that Plan B may be less effective for people who weigh more than 165 pounds (75 kg). The active ingredient, levonorgestrel, appears to have reduced efficacy at higher body weights.

For people weighing between 165 and 195 pounds, ella (ulipristal acetate) may be a more effective option. For those over 195 pounds, copper IUD is considered most reliable emergency contraceptive.

That said, there is no weight restriction on purchasing or taking Plan B. It is safe at any weight. It just may not be as effective at preventing pregnancy in people with a higher BMI. If this is a concern for you, discussing your options with a provider can help you find most effective choice for your body.

Can Plan B Affect Your Period?

Yes, it commonly does. After taking Plan B, your next period may come earlier or later than expected. It may also be heavier, lighter, or accompanied by spotting. These changes are caused by levonorgestrel temporarily shifting your hormonal patterns and are not a sign that anything is wrong.

If your period is more than a week late after taking Plan B, take a pregnancy test. A delayed period does not necessarily mean pill failed, but it is worth confirming.

For more on what to expect when your period is late and how to evaluate possible causes, this resource walks through topic: Delayed Menstrual Periods: Causes and Management

Conclusion

Plan B expires approximately four years after it is manufactured, and expiration date is printed on box. After that date, levonorgestrel can lose potency, and pill may not be as effective at preventing pregnancy. Storing it properly in a cool, dry, dark place helps it last through its full shelf life. Buying it in advance and keeping it accessible is one of smartest things you can do for your reproductive health. If your Plan B is expired, replace it. If you need emergency contraception and only have an expired pill, taking it is better than nothing, but getting a fresh one as quickly as possible is best move.