"If you don't have leukaemia, then taking this cancer drug might destroy perfectly healthy cells and tissues within your body," cautioned Dr Pravit Asawanonda of Chulalongkorn University's Division of Dermatology.

The warning came after Pravit received lots of questions from patients about the efficacy of using the leukaemia drug to whiten the skin, some saying that they had witnessed people turning paler after taking the tablets.

Pravit said leukaemia patients develop white spots, not a whiter complexion, from taking the drug. Developing white spots is a common side effect of the drug.