most cannaboids are metabolized in the liver, (but some are stored in fat too) it doesnt matter if you smoke it, vape it, eat it, use a transdermal patch, intravenous injection, take it sublingually, or rectally. Delta-9-THC is metabolized to 11-hydroxy-delta-9-THC through all of these methods of administration. 11-hydroxy is then metabolized into 9-carboxy-THC, which is a metabolite; this is what drug tests are designed to look for.

As far as synthetic thc or cannaboids, there are a whole wack of them. One of them is HU-210 (1,1-Dimethylheptyl-11-hydroxytetrahydrocannabinol) which mimics natural thc, but is 100-800x more potent. HU-210 is a full agonost, for the cb1 receptor, where as thc isnt, meaning that every single of thc's effects would be magnified by 100-800 times, making fatal overdoses possible!

Yay science.