Yes, you can drink water after using a Colgate whitening pen.
Whitening pens typically contain a peroxide-based formula that helps to lighten the enamel of your teeth. While it's best to avoid consuming anything that could stain your teeth for a short period after using a whitening pen, drinking water is safe and will not interfere with the whitening process.
However, it's important to note that some whitening pens may have specific instructions regarding the consumption of liquids after application. Always check the instructions on the product packaging for the most accurate information.
If you have any concerns about using a whitening pen, consult with your dentist. They can provide personalized advice based on your individual needs and oral health.