Hypothetically, drugusers could learn to carry a tiny UV LED light about the size of a penny on their keychain that would light up the particular QD colors assigned to Oxycontin or any drugs or supplements.

If the pill did not fluoresce at all or the right colors, they would know it was fake.

Human frailty aside, of course. There are probably functioning drug addicts to some degree whose lives would be saved by being better able to ensure the drug of their choice was actually being offered to them