I purchased this six months ago. I have stored it at home, avoiding high temperatures. Quality expiration date: 2027/6/16 Ingredients: Ascorbic acid (Vitamin C), Xanthan gum, Zinc gluconate, Taurine, Methylparaben, Propylparaben, Food coloring blue No. 1 How to use: (1) Remove the cap and applicator tip, and add the included Vitamin C to the gel. After confirming that all the Vitamin C has settled, reattach the applicator tip and cap, and shake well. (2) Lift your lips to the point where you can see your molars (you don't need to open your mouth), and tilt your head slightly to the side. (3) Apply a few drops to the upper molars on both sides, or apply directly with your finger, and spread it throughout the entire oral cavity. Storage: Avoid direct sunlight and store out of reach of children. After opening, be sure to store in the refrigerator.