When my friends smoke like a large amount of weed they get sick and vomit. How is it we green out and puke when marijuana helps nausea not cause it!

Well, here's the. Thing, you don't know how many pesticides & other dangerous chemicals have been mixed in with that marijuana. Inhaling poisons can make one feel ill.
Marijuana Paradox. There are a lot of possibilities: maybe the weed is so strong. Maybe what you eat is making you sick? Or drinking alcohol at the same time? People who smoke pot often get the munchies...Maybe they are eating too much. But, you got it right. Marijuana is well known to calm the stomach and treat abdominal pain and nausea.