Synthetic drugs (like heroin, methamphetamines, cocaine, etcetera) are pretty much disgusting. Like, seriously. Just terrifying. They're worse for you than cigarettes, for sure, but I'm pretty sure nicotine is more physically addicting, meaning if you were to stop smoking cigarettes after smoking for a long time, you would get more negative effects than if you stopped injecting heroin, save the coming down period. Mentally/emotionally, it's up for grabs, but "mental" addictions are stupid and pointless and barely addictions in the first place.
~D-Draw