This is usually caused by insulin resistance. I get the dark patches in my arm pits, my daughter on her inner thighs. This is usually what doctors give out metformin for... but I hate metformin, as an alternative you can try inositol powder Swansonvitamins.com is a good place to get it.
Chromium picolinate and berberine are also good alternatives, which you can find at most local vitamin shops. Not to mention it will help you in your efforts to loose weight.

Thank you @A myPCOSteam Member

Mentioned Users

A myPCOSt...

Your welcome i have been working out a lot lately to try and loss weight it was startkng to clear up, even my mom noticed it was clearing up but now it starting to get dark again😔and i still work out everyday and eat healthy. My mom and i even read last might if you eat right and work out pcos just go away for good. I really want this to end its so scary. Also how i am only 21 it scares me a lot.

I do...... It's on my inner thigh, under my breast and armpit. I was told by my doctor the best way for it to clear is wt loss. I'm here with you for recommendations too. It makes me super self conscious. Thanks for putting this question out there.