The New York Post reports how methylene blue is a type of salt with anti-fungal properties that’s typically used to clean fish tanks. It can also be prescribed to treat methemoglobinemia, a condition when blood isn’t delivering oxygen to different parts of the body properly.

The same Post article continues to report, however, that—for some reason—many Influencers have begun consuming methylene and touting it as something that does wonders for the metabolism—and occasionally as an anti-aging supplement—to their followers.