With U.S. Covid-19 cases approaching 1 million, the Federal Trade Commission warned about marketing firms’ health claims about unproven treatments.

Multi-level marketing firms “and other companies that distribute their products through networks of distributors are responsible for the product and earnings claims those distributors are making,” said Andrew Smith, Director of the FTC’s Bureau of Consumer Protection in a Friday news release. “During this health and economic crisis, we are on the lookout for false income claims...