RELATED: Never Do This When You Shower in the Morning, Doctors Warn. London-based dentist Anna Peterson went viral on TikTok after telling followers that they’ve been doing their toothbrushing routine in the wrong order for years. According to Peterson, you should never be using mouthwash after you brush your teeth. Instead, she suggests using a rinse before brushing your teeth or after you eat. As the U.K.’s National Health Service (NHS) notes, “Using a mouthwash that contains fluoride can help prevent tooth decay, but don’t use mouthwash (even a fluoride one) straight after brushing your teeth.” RELATED: Don’t Use Mouthwash If You’re Taking These 2 Medications, Experts Warn. Using mouthwash right after brushing your teeth is bad practice because it will “wash away the concentrated fluoride in the toothpaste left on your teeth,” the NHS says. Peterson explained that mouthwash has lower fluoride concentrations than toothpaste. The fluoride in mouthwash is “not enough to protect your mouth from sugars that you’re going to eat and drink,” she said. “So when you brush your teeth, and then you rinse with mouthwash straight away, you just rinse out all the high concentration fluoride for low concentration fluoride.” Fluoride is beneficial to your teeth, so you don’t want to wash it away. According to Healthline, fluoride helps rebuild weakened tooth enamel, slow the loss of minerals from tooth enamel, reverse early signs of tooth decay, and prevent the growth of harmful bacteria. According to Peterson, not everyone needs to use mouthwash. However, using it at the right time can’t hurt. West End Dental says using mouthwash regularly can help prevent periodontal disease, reduce cavities, and keep your breath feeling fresh. Some people can benefit more than others from mouthwash, such as those with medical conditions like dry socket, tooth sensitivity, or dry mouth, the dental experts note.ae0fcc31ae342fd3a1346ebb1f342fcb RELATED: For more health advice delivered straight to your inbox, sign up for our daily newsletter. The NHS instructs that you shouldn’t “eat or drink for 30 minutes after using a fluoride mouthwash.” Experts also warn that you shouldn’t brush your teeth for 30 minutes after eating. Jeannie Grecco, DDS, of Rejuvenation Dentistry, previously told Best Life that this is because digestion starts in the mouth and creates an acidic environment, which is not a good condition to brush your teeth in. Jin Lin, DMD, the owner of Hurst Pediatric Dentistry, previously explained to Best Life that when you eat food containing sugar or simple starches, bacteria in your mouth feed on them and produce acid. “When your teeth are exposed to a highly acidic environment, it temporarily weakens your enamel (the hard, outer surface of the tooth) by causing it to lose minerals. Rubbing your enamel with a toothbrush when it is in this weakened state may further damage the enamel.” RELATED: Never Do This When You Shower at Night, Doctors Warn.