It is worth noting that although kojic acid yields greater stability than does hydroquinone, the fungal derivative does have labile oxidative properties, which are enhanced by light and heat exposure. For that reason, the inclusion of kojic acid in cosmetic formulations has been through its dipalmitic ester (as kojic dipalmitate) (Talanta 2008;75:407-1).
Conclusion
The fungal derivative kojic acid has maintained a significant role in the dermatologic armamentarium for 2 decades as a skin-whitening agent and is best used in combination with other depigmenting ingredients, which enhance the overall effect of the formulation and blunt the irritating effects of kojic acid. Recent evidence has allayed fears regarding long-term carcinogenic effects, but as always, research is ongoing to develop newer, safer derivatives.