'FDA approval' has a certain glow of authority to it. In most people's minds to be FDA approved is to be safe, effective, and proven. Or at least, it technically is. Technically, FDA approval is a stringent process that requires a degree of proof. You might like to think that you couldn't get away with claiming something went through that process if it never really did. But you'd be wrong. And if you wanted to, say, market an unproven negative ion bracelet as a treatment for 'harmful' electromagnetic fields that aren't actually harmful, you could totally get away with it.