Yes, cocoa is a drug, but there's hardly any of the psychoactive substances in most chocolate confectionery items. To get serious amounts of it, you need really dark, bitter chocolate with >75% cocoa content. And anyone comparing it to heroin must be taking something much stronger.
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/xfacepalm.gif.pagespeed.ic.EBDwh1hCfo.png)
Oh and cigarettes are only harmful because of all of the tar and nasty chemicals present in the smoke. Pure nicotine cause a similar level of harm as caffeine, so not good, but it doesn't cause cancer. Don't listen to all the BS propaganda about ecigs pushed by the tobacco companies.