A new study says Medicare patients prefer cheap generic drugs only when they’re footing the bill themselves—when government pays, they want brand names. Recent news may shed some light on why: the FDA is investigating reports of faulty generic Wellbutrin, and last month it banned 28 generics made in India. If you’re taking a generic, should you switch to a brand name? Probably not. All generics, prescription or over-the-counter, go through a rigorous approval process. Generics are supposed to be “bioequivalent” to their costlier cousins (their active ingredients are equal in dose, safety, strength and efficacy). Although their inactive ingredients (such as flavors and dyes) differ, it’s very rare for those to cause reactions. Generics made in the United States are manufactured under the same standards as brand names. But the FDA has no authority to oversee those made abroad. (India and China make about a fifth of the generics sold here.) The agency’s only option is to ban those drugs and demand manufacturing upgrades, as it did last month. It also assured consumers there’s “no evidence of harm” from what’s already on the market.