I have dark underarms, what should I do? (photo)

Our top treatment for underarm pigmentation includes Luminase and EXfolase creams followed by fractional laser. Best, Dr. Karamanoukian#Realself100 Surgeon

The darkness is likely from the pigmented hair roots.  These are the targets of laser hair removal systems.  Often several sessions are required to remove a significant amount of the pigment.  Many cities have a number of salons that offer these services.  I would recommend sticking with offices where there is a doctor present to supervise the treatment. Before you have this service, you will benefit from an examination the skin by a dermatologist to make sure this does not represent Acanthosis Nigricans.  Acanthosis nigricans warrants some additional testing by the dermatologist to look for certain medical conditions that can also cause this appearance.

Maybe the posted photo do not demonstrate the "dark" axillary areas? But aggressive bleaching with a hydroquinone product is best therapy.