Hello. Thank you for writing to us Glycolic acid is the active ingredient present in this cream, it is a skin lightening agent, therefore I doubt that darkening is due to glycolic acid. I don t think you have been using this cream the right way. The cream that you have been using is fine if you use it at night rather than day. A sunscreen is an essential part in the management of facial pigmentation. They prevent further sun induced darkening. Therefore, day time, I suggest you to use a broad spectrum sunscreen, throughout the day. A sunscreen should be reapplied every 2-3 hours. At night you may use a cream containing one or more of the following skin lightening ingredients like kojic acid, glycolic acid, hydroquione, arbutin, Azaleic acid etc. You may also opt for a few sessions of chemical peeling from your dermatolgist. Glycolic peel is particularly suitable for post-inflammatory hyperpigmentation from preceding acne. I suggest you to visit a dermatologist in your region for the needful. Regards