Americans spend billions on healthcare products, from green powders and cold plunges to costly gym memberships. Last summer we asked: what good do they do? This episode was produced by Hady Mawajdeh, edited by Miranda Kennedy, fact-checked by Melissa Hirsch, engineered by Matthew Billy, and hosted by Jonquilyn Hill. Visitors wear the Myblend myLEDmask2 "Anti-Aging" product at the FIBO trade show…