How effective is kojic acid?
Kojic acid is normally used twice a day for 1-2 months for the lightening of dark spots or the treatment of melasma. According to Baumann-cited studies by Ellis and Garcia, kojic acid combined with glycolic acid was more effective than 10% glycolic acid or 4% hydroquinone for the treatment of hyperpigmentation. A third Baumann-cited study by Lim et. al. found that 2% kojic acid in combination with 10% glycolic acid and 2% hydroquinone further improved melasma symptoms over a mixture of 10% glycolic acid and 2% hydroquinone alone. Kojic acid, glycolic acid, and hydroquinone are all found in Age Advantage Laboratories Spot Life Serum ($41.34, Amazon.com). Unfortunately, the concentration of kojic acid, glycolic acid, and hydroquinone in this product has not been published, so the above studies may not apply. (No products could be found that publish 2% kojic acid, 10% glycolic acid and 2% hydroquinone). Age Advantage Laboratories Spot Life Serum also contains retinol and alpha lipoic acid
