I was going to a friends wedding over the weekend and did not have a 2 weeks to wait for results (i.e. trays) and did not want to spend $500 at the dentist office. With this product my teeth were definitely brighter after about an hour. The 3 step process (rinse, apply the gel, and whitening light) was repetitive, but I did not mind since I was completely done with the entire treatment in 1 hour. Best of all- I did not get any tooth sensitivity. Quick, Effective, Great Product. WELL WORTH THE MONEY!!