Zyban was originally marketed as a antidepressant under the brand name Wellbutrin. The generic name of this drug is bupropion.
Soon after patients on this drug began reporting that they stopped smoking. And studies showed that Zyban reduced the severity of nicotine cravings and withdrawal symptoms and thus improved the chances of quitting smoking up to 20%. Other desirable side-effects where increased libido and weight loss. The most commonly observed adverse events consistently associated with the use of Zyban are dry mouth and insomnia.
Zyban eventually gained FDA approval as the first nicotine-free prescription medicine for smoking cessation. It was also the first smoking cessation treatment available in tablet form (before Chantix) and became available by prescription in July 1997.