Mastodawn

Most (but not all) things people promise will boost metabolism fall into two categories: “There are things that are dangerous and illegal and things that are BS, and you should probably avoid both of them” https://scientificamerican.com/article/can-you-change-your-metabolism/
by @ejwillingham

Though you might not be able to significantly rev up your metabolism, there are ways to boost the energy your body burns while doing nothing

Scientific American