Hi there...from what I have read, Nyquil can become physically and psychologically addictive...just like many over the counter drugs. If taken long term, it should be weaned. In this same article, it states that if taken for the recommended period of time (I forget what that is...LOL) and if you don't increase the dosage, it is safe. Apparantly, it can lose it's effectiveness over time and people think because it is not a prescript
ion, there is no harm in taking more than the directions advise. It also contains Tylenol and if you take other pain killers that contain this, it can be easy to exceed the safe limit of 3000mgs a day.
Donna