In an Instagram video posted on Thursday, Owens praised the use of colloidal silver as a daily supplement, a treatment that comes with no valid medical use and plenty of health risks.

“Yes, colloidal silver!” Owens said in the video. “I take colloidal silver every single day, I love colloidal silver. That is a great one. That is another one that people probably know nothing about.”

While Owens and others have praised preventative use of colloidal silver as a way to stave off illness, colloidal silver has no valid medical purpose and plenty of potential dangers. In extreme cases, according to the Mayo Clinic, colloidal silver can cause seizure or organ problems…

But colloidal silver’s most famous side effect is argyria—a condition that turns users’ skin a bluish-gray color, usually permanently.