It’s one of the worst flu seasons in years, but when you go to the drugstore for some relief, sorting through all of the over-the-counter options can make your head spin.

Consumer Reports has some advice on how to decode treatments for the flu and other ailments.  

The drug aisle can be confusing because labels like “extra strength,” “maximum strength,” and “ultra strength” have no standard definition.

For example, ultra-strength Tums has 100 per cent more of its active ingredient than the regular version. But Gas-X Ultra-Strength has 125 per cent more of its active ingredient.

"The point is you really have to read the label in order to know how much you're taking," said Dr. Marvin Lipman of Consumer Reports.   

Over-the-counter drugs that claim to be “all-day” and “long-acting” are tricky, too.  All-Day Aleve lasts up to 12 hours. But some all-day medicine lasts 24 hours.

Many drugs that are labeled as “PM” or “non-drowsy” can also be confusing. If the label says “PM,” the drug probably contains an antihistamine that will help you fall asleep. But if the label says “non-drowsy,” don’t assume the drug will help you stay alert. Only some have caffeine or another stimulant that will keep you awake.

If you take drugs that claim to relieve multiple symptoms, such as cold and flu symptoms along with a sore throat, you could end up taking something you don’t need.

“Drugs that treat multiple symptoms often have more than one ingredient, sometimes as many as four,” Dr. Lipman said.

So if you are taking another medicine that contains one of those ingredients, you might wind up taking too much.

Consumer Reports says it’s best to choose a single-ingredient drug whenever you can, such as ibuprofen for aches and pains or acetaminophen for a fever or headache.

And when in doubt, check with a pharmacist for help interpreting over-the-counter drug labels.