Definitely ^, I would go with morphine over heroin 9 times out of 10.
They are essentially the same drug, heroin is an ester salt of morphine and a morphine prodrug. It quickly converts to morphine as soon as it crosses the BBB, even heroin's other very, very minor metabolite 6MAM is quickly converted to morphine in the brain. Heroins real name is "morphine diacetate" or also called "diacetylmorphine". Doing heroin is essentially doing a faster-acting form of morphine, as morphine is totally responsible for the high.
