Pharmacist Dr. Stacia Woodcock stopped by the show to talk about some common medicine myths. To make healthy living more fun, she challenged the studio audience to a round of "true or false?" — and Rach played along, too!

Dr. Stacia's first question is about whether or not drinking alcohol while on an antibiotic decreases its effectiveness.

True or False? Alcohol makes antibiotics less effective.

The answer? False, according to Dr. Stacia.

"You should not drink alcohol when you're on antibiotics," Dr. Stacia says, but it typically "has nothing to do with effectiveness."

Wait, what?!

Dr. Stacia says the main reason why you shouldn't mix antibiotics and alcohol is because drinking alcohol causes dehydration and suppresses your immune system, which is already compromised when you have an infection. Also, she explains that the combination of alcohol and antibiotics can cause stomach upset.

In fact, there are certain antibiotics that, if you drink while you're on them, will make you really sick, the doc warns. This is due to an interaction called a disulfiram reaction, Dr. Stacia says, that causes nausea and vomiting. She explains that's where the effectiveness "myth" came from, but that the issue is not really effectiveness-based for most antibiotics.