Use a gentle exfoliant 2–3 times per week
Apply a moisturizer with niacinamide, lactic acid, or urea
Use products with vitamin C, azelaic acid, or kojic acid
Avoid friction by wearing loose, breathable clothing
Keep the area dry and reduce sweating when possible
Stop shaving irritation by using a sharp razor and shaving gel
Consider waxing or laser hair removal if shaving causes darkening
Use sunscreen on exposed inner thighs when applicable
Avoid harsh scrubs, bleaching creams, and DIY lemon treatments
Maintain a healthy weight if friction is contributing to darkening
Treat any fungal infection, rash, or irritation promptly
See a dermatologist if the darkening is sudden, severe, or persistent