Do you have a few bottles of Advil or Tylenol lying around that are older than the family pet? If it’s been a few years since you’ve cleaned out your medicine cabinet, there’s a few things you should know medical expiration dates.

“There isn’t a ‘magic date’ for most over-the-counter medications,” says Ana Ondrizek, a clinical pharmacist at Jackson Medical Center for Longterm Care in Miami.

“The expiration date is the date until which effectiveness is guaranteed. After this date, the drug may still work, but it will lose its potency and effectiveness over time.”

But Ondrizek, who also works as a medical science liaison for Boehringer-Ingleheim, tells Newsmax Health that taking many meds after their expiration date is not dangerous.

“There are no adverse effects to taking expired over-the-counter medications like Tylenol or Ibuprofen,” she explains.

Some prescription drugs and antibiotics, however, are not good to use past their prime and may even cause adverse health effects. If you’re uncertain, check with your doctor, experts advise.

In addition, Ondrizek, the AARP, and other health specialists recommend the following strategies to keep your medicine cabinet at full strength and safe:

Steer clear! While many medications are safe to use after their expiration date has passed, some over-the-counter and prescription drugs should not be taken past their prime. Pharmacist Margaret Wegelewski tells Newsmax Health that expired eye-drops are a no-go: “After the expiration date passes, the preservatives in the eye-drops no longer work, and they won’t be effective.”

Additionally, there is a high risk of bacterial growth in eye-drops past expiration, which could result in loss of vision if used.

Other common medications that should not be take past their prime: Insulin, asthma inhalers, EpiPens, oral contraceptives, oral nitroglycerin (NTG) for angina (chest pain), anticonvulsants, warfarin, digoxin, and thyroid preparations.

Antibiotic prescriptions should also be taken in full (cutting doses short can increase the risk of antibiotic resistant microbes), and leftover antibiotics that have expired should be disposed of as well.

“Some antibiotics, like tetracycline, have adverse effects if used past expiration,” explains Ondrizek, “and others will become ineffective or lose their potency.”

There’s a difference. Sometimes medications have both an expiration date and a “use by” date printed on the bottle. The expiration date is used in pharmacies, where the drugs are stored and dispensed to patients, and the pharmacy often gives patients “discard after” or “do not use after” warnings that come sooner than the expiration date, usually a year before.

This is for safety concerns rooted in the fact that the medication is no longer being stored at the pharmacy. In some states, the “use by” date is required by law.

Keep it cool. While kitchen counters and bathroom medicine cabinets are a convenient place for medications, they’re not the most ideal. Drugs do not fare as well in places with stovetops and showers that create heat and humidity.

“Medicine should be kept in dry and cold places,” Ondrizek explains, “it doesn't need to be refrigerated, but the humidity from bathrooms is not great for drug strength.”

Additionally, keeping “just in case” medication in your glove compartment could expose them to extreme temperatures, which could render them weak or even ineffective.

Spring cleaning. Ondrizek advises that medicine cabinets and collections be cleaned out every six months, disposing of any over-the-counter medications or painkillers that have expired. By doing this, you can ensure that all your medications are potent and effective.

Dispose safely. After cleaning out your cabinets, it’s important to safely throw away the expired medications. More than 50 percent of people who abuse drugs like painkillers, tranquilizers, and stimulants get them from a friend or family member, more often than not without their knowledge, according to the 2011 National Survey on Drug Use and Health.

To avoid this, you can crush up unused pills and put them in places no one would think to go, like empty liquid bleach bottles or used cat litter. Avoid flushing crushed medication down the toilet, though, because this can contaminate drinking water.