A. The Ultrasun Aftersun Serum can be used as a tan accelerator. If you use it about three or four days before sun exposure as a body moisturiser, it doesn't increase the melanin levels but does increase the hydration levels in the skin and calms the skin down so your skin responds to the sun in an easy manner.
You can also try a specific tan accelerator from Elemis, which is a top seller. This can be used as an aftersun too to stop your tan from fading when you get back from your hols.