Does your co-worker’s first explosive sneeze or your child’s burgeoning cough send you to the store for zinc supplements to protect yourself from catching their cold? It’s true that some studies have found that zinc supplements may shorten the duration of a cold, but there’s no proof that it will prevent one, or ease symptoms such as your runny nose or aching head.

And beware: Zinc has side effects, too. Nevertheless, consumers spent about $108 million on zinc supplements in 2014, according to the Nutrition Business Journal.

Here are six reasons to keep the cash in your pocket and skip the zinc this cold season.

1. Zinc Won’t Relieve Your Cold Symptoms
Zinc is no magic bullet. An April 9, 2014, review in the Journal of American Medical Association analyzed studies of 1,781 cold-riddled participants in the U.S., the U.K., and elsewhere. Some received zinc-laden lozenges or syrups while the rest were given placebos. Those who began taking zinc regularly 24 to 48 hours from the onset of their colds reportedly got better about a day before those who took the placebos. But the analysis found that taking zinc had no effect whatsoever on the severity of the symptoms.

2. This Supplement Has Side Effects
While slicing a day off your suffering may sound great—and there is evidence that zinc ions have an antiviral effect, at least in a petri dish—the reality is that taking zinc can have some pretty unpleasant side effects. These include leaving a foul taste in your mouth and making you feel nauseated.

"Although zinc products may reduce a cold's duration by a day or so if started early enough, the bad taste and nausea can make the treatment worse than the disease," says Consumer Report’s chief medical adviser Marvin M. Lipman, M.D.

3. Zinc Can Be Toxic
A healthy adult woman should get a minimum of 8 milligrams (mg) of zinc per day, and adult men 11 mg, but that amount is easily obtained through a healthy diet that includes zinc-rich foods such as poultry, red meat, and fortified breakfast cereal.

In fact, the National Institutes of Health advises that unless you’re taking zinc for medical reasons under the care of a doctor, the maximum daily limit you should get is 40 mg. Too much can cause nausea, vomiting, stomach cramps, diarrhea, and other problems.

4. It Can Interact With Your Other Meds
Zinc has been shown to interact with various prescription medicines. For example, take it with tetracycline or quinolone antibiotics such as ciprofloxacin (Cipro and generic) and you’ll reduce the amount of both the zinc and the antibiotic that your body absorbs. It can also interfere with the absorption of penicillamine (Cuprimine, Depen), a drug used to treat rheumatoid arthritis and Wilson’s disease (a rare genetic disorder).

5. Zinc Can Cause Health Problems
Getting too much zinc may increase the risk for prostate cancer, lead to copper deficiency and neurological problems, and reduce levels of HDL (good) cholesterol. What’s more, zinc products may also contain cadmium (another metal that is chemically similar and occurs alongside zinc in nature), and long-term exposure to high levels of cadmium can lead to kidney failure.

6. You Might Lose Your Sense of Smell
Avoid using zinc in the form of nasal preparations, which can make you lose your sense of smell. Several years ago, the Food and Drug Administration took several zinc nasal products off the market after receiving more than 130 reports from people who had used certain nasal Zicam Cold Remedies and lost their sense of smell—some permanently.

On balance, staying hydrated and getting plenty of rest will do more to help you recover than any supplement—and a bowl of chicken soup won’t hurt either.