Oils and concentrates are "suboptimal forms" of the plant, said Sisley, who investigates marijuana's effects on PTSD in veterans and opioid withdrawal. "It's like the difference between an orange and orange juice," she said. "Flower gives you the natural entourage effect. There are 400 bioactive molecules in the plant, 130 plus cannabinoids and dozens of terpenes and flavinoids. The theory is that the molecules all work together. Processing into oils and concentrates strips many of them away."