nicotine is worse than heroine - i never tried heroine but it's hard to kick cigarettes, i figure chemical drugs are far worse than chemical addiction safe ones, such as alcohol, marijane, perhaps in moderation. most habits in life can become psychological, and even if a drug has no chemical that leads to addictive phisiological affects you may become addicted psychologically.
psyched out drugs tend to give people major paranoia. all plants like cacti and mushroom are best avoided unless your an indigenous shaman or in the presence of an indigenous shaman you trust.
p.s nah ill give up cigarettes one day, besides that even alcohol i see as detrimental to my wholesome wonderful self ;P