Probably intended to be funny, but in my usual style I'll answer seriously. If you were to write a story about, say, an herb that's found that cures cancer, that would be legitimate SF to me. It might not be hard SF if there's no explanation of how it cures cancer, but it's enough to say there's a compound in the plant that does it, because that's how medicine works.
The thing about homeopathic medicine that makes it non-science is that, for much of it, there's zero scientific evidence that it works. But in the confines of a story, if the author says it works, them it works.