• First: Calcium supplements and antibiotics. Because the calcium stops your body from absorbing the antibiotic. You can still take calcium, just do it at least 3 hours before or after your antibiotic.

• Also, don’t combine antihistamines and antidepressants. It can cause extreme drowsiness. So if you have allergies and you’re on antidepressants, ask your doctor what pills can clear your sinuses and relieve watery eyes without the sedating effects.

• Lastly, ladies, if you’re on the Pill, steer clear of St. John’s Wort. It can make oral contraceptives less effective… Because it breaks down estrogen, increasing the odds you’ll get pregnant even if you’re on the Pill.