Nature's Method CBD : Depending on who you ask, CBD oil is good for what ails you, whether that be anxiety, anorexia, insomnia, PTSD, chemotherapy-induced nausea and vomiting, depression, migraines, or feeling chronically unchill. And even within your own body, you can build up a tolerance level, which may mean taking a break every once in a while. "I suggest women take periodic cannabis fasts to allow the endocannabinoid system to reset," Chin said.