What happens if FLEX is worn for more than 12 hours? Sarah October 18, 2018 14:11 Updated Follow FLEX is FDA registered and tested to be worn for 12 hours. Related articles How do I insert and remove FLEX? Will FLEX work for me if I have a tilted uterus? Can you pee, poop, swim, and sleep while wearing FLEX? I can't get FLEX in. I have a heavy period. Will a menstrual disc work for me? Comments 4 comments Sort by Date Votes Riana Kaempen February 20, 2018 23:26 This doesn’t answer the question. It’s been previously stated that it’s registered and tested for 12 hours, we know that. I want to know the side effects/risks/consequences if it’s accidentally worn for longer than 12 hours. 2 Permalink Misty Dake March 28, 2018 17:19 I too would like to know what could happen if left in for too long. 1 Permalink Katy Allen October 17, 2018 11:48 I forgot my flex in and need answers on what happens when it’s left in too long 0 Permalink Riana Kaempen October 18, 2018 14:11 I’ve been told that there’s no association with TSS and it’s safe to wear longer. I literally leave one in for 2 or 3 days until the worst of my cycle is over and I’ve never had anything bad happen. 0 Permalink Please sign in to leave a comment.