To see a noticeable difference in your skin, it is recommended that you use this ice roller regularly and consistently for 3-4 months. Patch tests are easy to ensure you don't experience any initial adverse reaction when using a new product. We recommend doing a patch test before starting any new product on your skin. You can conduct a patch test by following the below steps: 1. Apply the product to a small patch of skin either to the arm or bend of the elbow 2. Keep the area dry 3. Leave on for 12-24 hours (or lesser if the product isn’t a leave-on product) 4. If any redness, itching, or irritation is observed at any time during the test, do not use the product, else you can safely use it