A rapid (or express) tanning solution is a DHA-based sunless tanning product that allows you to shower much faster than traditional formulas. Instead of waiting 8 to 24 hours, you rinse off the cosmetic bronzer in just 1 to 3 hours, while the active tan continues to develop on your skin over the next 24 hours. Rapid solutions are specially formulated to accelerate the initial reaction between DHA and your skin's amino acids.