teeth Whitening Essence Oral Hygiene Cleaning Essence Removes Plaque Stains Brighten Tooth Whitener Serum Dental Tool Toothpaste Usage for Teeth Whitening Serum: Before use please clean the mouth with warm water then use a cotton swab to dip proper amount of the product wipe the teeth surface evenly and rinse it with clean water after 15-20 minutes we recomend to use 2-3 times per week. Tips: 1. When removing the stains please wipe gently so as not to damage the gums and oral mucosa; 2. Properly wet the cotton swab when it is soaked making sure it is not too wet; 3. It takes about 1 min to wipe each tooth; 4. If the stains can't be removed completely please use again after a week; 5. Children under the age of 13 should not use it. Do not try to swallow. Storage:After use please tighten the cover store it in a cool and dry place so as to avoid direct sunlight.