They aren't very strong, probably made for people who don't smoke. My friends sister traded me some for weed because they didn't do much for her. I just thought they were cool, but I took a couple and didn't feel much. Tried breaking one open and smoking the oil, that didn't work either, and tasted awful. They are a little gel cap, round in three dimensions, like a basketball, and sorta skin tone color. Never heard of Sativex before, sounds cool, anyway!