An Eli Lilly drug if approved for weight loss could become the best-selling drug of all time, but concerns are mounting about who will actually be able to afford it. If that’s the case, it would join two other popular — and expensive — recently approved weight loss drugs on the market, Wegovy and Saxenda, both from the drugmaker Novo Nordisk. The drugs have been shown in clinical trials to be highly effective for weight loss. Are weight loss drugs covered by insurance? What’s more, Butsch said, not everyone responds the same way to any given weight loss drug.