Like pure indica, pure sativa strains are high in THC content, which can cause hallucinogenic responses. Generally speaking, indicas are recommended for night-time use, while sativas are a better choice if you need to function during the day, but still take the edge off pain. Of course, most of the medical marijuana people get from dispensaries is neither pure indica nor pure sativa, but a hybrid of both. Some lean more toward the indica part of the scale, others toward the sativa, while still others are nearly 50%-50% hybrids.