Medicinal cannabis is not just regular pot.There are hundreds of different cannabinoids which bind with receptors in our bodies, Research at the moment is looking at which ones do what. It's a very complex issue. Garden variety marijuana has been selectively bred to increase THC which gets you stoned. Once useful cannabinoids have been identified the trick will be to breed strains with high levels of those compounds.
I used an infused oil during treatment which, I think, helped with nausea and some of my pain issues.
There are trials in place now looking at how cannabis may help with exactly those issues and appetite during chemo.