You're right that they can't use LSD straight. But they can develop a nearly identical molecule with identical effects, shepherd that molecule through the FDA

You're right that they can't use LSD straight. But they can develop a nearly identical molecule with identical effects, shepherd that molecule through the FDA approval process, and then have a profitable monopoly. Which on one level sucks but on another level means that if we really can benefit from LSD as a drug then we should expect Big Pharma to let us get it through our doctors once the regulatory/legal barriers to using it go away.