2x a day. 24 hour protection against plaque & gingivitis germs. Use every 12 hours. Kills germs that cause bad breath, plaque & the gum disease gingivitis. ADA accepted - American Dental Association. Clinically proven. Kills germs by millions on contact. Use Cool Mint Listerine Antiseptic twice daily to help: prevent & reduce plaque; prevent & reduce gingivitis; freshen breath; kill germs between teeth. The ADA Council on Scientific Affairs Acceptance of Cool Mint Listerine Antiseptic is based on its finding that the product is effective in helping to prevent or reduce gingivitis and plaque above the gumline, when used as directed. Council on Scientific Affairs, American Dental Association.