Siya black teeth whitening foaming liquid is a product designed to whiten teeth and remove stains. It typically comes in a bottle with a pump dispenser and contains a foaming formula that helps to penetrate and lift surface stains from the teeth. The active ingredients in these products can vary, but often include hydrogen peroxide or carbamide peroxide, which are commonly used in professional teeth whitening treatments. To use a teeth whitening foaming liquid, you would typically apply a small amount to your toothbrush and brush your teeth for a specified period of time, as directed by the product instructions. Some products may require you to rinse your mouth thoroughly afterwards, while others may not. Its important to note that while teeth whitening foaming liquids can be effective in removing surface stains, they may not be suitable for everyone. People with sensitive teeth or existing dental problems should consult with a dentist before using any whitening product. Its also important to follow the instructions carefully and not overuse such products, as they can potentially cause damage to your teeth and gums