I try to keep up on whatever foods, plants, and other substances may be dangerous for my dog. This is one I had not previously heard of until recently. Minoxidil is the active ingredient in hair loss products, many of which are now available over the counter. It sounds like it is bad news for both dogs and cats (and I'm sure other types of pets, too).
Topical Minoxidil Exposures and Toxicoses in Dogs and Cats: 211 Cases (2001–2019) | Journal of the American Animal Hospital Association