Chantix
Chantix Overview

Chantix (generic: varenicline) is a prescription medicine used along with education to help people quit smoking. Chantix is in a class of medications called partial cholinergic nicotinic agonists. While it does not contain nicotine, it works by stimulating nicotine receptors in the brain, reducing cravings for cigarettes. It also decreases the pleasurable effects of cigarettes.

Chantix comes in tablet form and is typically taken twice a day, after food, with a full glass of water.  
 
The most common side effects of Chantix are nausea, sleep problems, constipation, and headache.