Does it work on opiod receptors? possibly. will you enjoy taking it? you decide. it has been tested for its treatment of pain and there have been affirming results, and it is in the same family as opium poppy - but then again, so is the chinese poppy, which is more closely related, and there are no claims of it being a psychoactive herb. eastern wild lettuce is the species which has been proven to have any medical use, the american species i think is inactive. keep in mind that the dosages for this herb would be pretty high for you to notice anything. dont take half a gram of dried herb or 15 drops of a 1:5 tincture and expect to feel a single thing. think along the lines of kratom - several grams of dried herb, at the least. but like SPEED KING says, start low and work your way up if you're serious about this. You never know what your body is sensitive to.
if you're really curious about this plant then look up the materia medica on wild lettuce via google - there are many many sources of this online - and you will get an idea of what to expect.