No question in my mind; it will simply reduce the amount of oil collected, if you juice it first.

I think the "Life Force Energy" of juicing raw plant material, plus the raw CBDs should be a great alternative to oil, and for someone fighting cancer, just one more way to make the nutrients available to the body.

Leaves are very high in CBDs and there will still be plenty of THC present as well in both the juice and the oil.