Thanks for the query.
Dark spots could mean many things. I assume what you mean is post inflammatory pigmentation. Targeting through a single agent may not always be fruitful. Meet a qualified Dermatologist to learn more about the diagnosis and treatment options. Combination of different therapeutic agents is always beneficial. Revlite I.e. Q-switched Nd YAG laser has been available for stubborn pigmentation and can be helpful when topical creams fail. Hope it helps.
Next Steps
You need to frame your query more appropriately to get a precise recommendations, A photograph would have been helpful.
Health Tips
Apply Sunscreens regularly.