What you will notice

First week: very little to see. Pigment is made and then has to be handed up through the skin layers, so colour lags the dose by days. Weeks one to three: the colour comes in, evenly, on the face, neck and arms first, peaking one to three weeks after dosing ends, which is the pattern the original work measured. Weeks four to eight: with the specialist implant this is the working plateau, where light-intolerant skin reports its outdoor hours, and where one implant's effect is tailing off and the next is due at about two months. Longer: colour fades over one to two months once dosing stops as pigmented cells are shed, and in light-intolerant skin the implants are repeated through the sunny months, three to five a year. Any mole that darkens, grows or changes shape at any point is a reason to stop and be seen.