I have PCOS and the skin around my neck suddenly turned black, how to treat this pigmentation?

Localized hyperpigmentation around the neck and lips in PCOS patients is not a sun tan; it is a clinical condition called Acanthosis Nigricans. Dr. Divya Sharma, MBBS, MD Skin, confirms that high blood insulin levels, which commonly occur in Polycystic Ovary Syndrome (PCOS), cause this specific dark, velvety hyperpigmentation on the neck.

The chest region remains fair because Acanthosis Nigricans specifically targets intertriginous areas (skin folds) where friction is higher. Elevated insulin binds to insulin-like growth factor receptors on the skin, causing keratinocytes (skin cells) to multiply rapidly and thicken into a velvety texture. Simultaneously, changing hormones—particularly excess estrogen and progesterone—trigger active melanin production, causing dark patches around the mouth. A clinical study of 1204 women across four Indian cities revealed that over 80% of the population presents with skin color heterogeneity like this, which is exacerbated because people of Indian descent naturally have higher baseline melanin production.

Clinical Protocol for Acanthosis Nigricans & Localized Pigmentation

To treat this, you must address both the thickened skin texture and the overactive melanin synthesis using targeted actives:

• Step 1: Chemical Exfoliation (PM, 2-3x a week): Apply a 7% Glycolic Acid toner to the neck. Glycolic acid (an alpha-hydroxy acid) breaks the bonds between dead, thickened keratinocytes, accelerating cellular turnover to shed the velvety layer.
• Step 2: Tyrosinase Inhibition (AM & PM, Daily): Apply a 10% Niacinamide serum to the neck and around the lips. Niacinamide disrupts the synthesis of melanin by inhibiting the enzyme tyrosine hydroxylase, preventing further localized darkening.
• Step 3: UV Protection (AM, Daily): Sun exposure worsens hyperpigmentation. Apply a broad-spectrum SPF 30+ sunscreen containing physical blockers like zinc oxide or titanium dioxide daily to prevent UV-induced melanin spikes.