I'm not sure exactly what it does, but it's something we picked up from Fadi's mother (who is chock full of little home remedies - some effective, some silly). It does add a nice taste, but I've noticed it is soothing for a sore throat. Oh! And I just remembered another one, to help a sick tummy drink mint tea. Especially if you have a tea strainer and dried mint flakes or leaves. :-)