Hello Saily, darkening of body folds in females could be because of multiple factors like hormonal imbalance, acanthlsis nigricans & obesity. It can be lightened up with the help of peels, creams and lasers. Certain oral medications and creams will also help to lighten it further. It is advisable to treat it from the root cause.
Next Steps
Consult online with pitcures to get proper guidance
Health Tips
Take Vit C supplements on a daily basis