How to reduce dark underarms

Check what is causing the darkening

Shaving irritation, tight clothing, product reactions and excessive sweating can contribute to dark underarms. Post inflammatory hyperpigmentation means darker marks left after inflammation or injury. Treating the irritation helps stop new marks from forming.13

Thick, dark, velvety patches can be acanthosis nigricans, a skin change that often appears in the armpits, neck or groin. It can occur in otherwise healthy people, but it is also associated with obesity, diabetes, hormone conditions and certain medicines. A doctor can examine the patches and arrange tests, including blood sugar testing when appropriate. Washing will not remove acanthosis nigricans.245

Seek medical assessment promptly if thick, dark patches appear suddenly or spread rapidly. Also arrange an appointment if itching and inflammation persist after changing deodorant, or darkening occurs with irregular periods, unusual hair growth or weight gain.15

Start by reducing irritation

1. 1Cut back on the products you apply under your arms. Start by removing unnecessary treatments rather than layering more products over irritation.
2. 2If deodorant causes a rash or irritation, change it. Look for products intended for sensitive skin and without fragrance.
3. 3Reduce friction from tight clothing and reconsider shaving if it irritates the area.
4. 4Once the cause is addressed, discuss a lightening treatment with a doctor if the darkening still bothers you.

Natural products can still contain fragrance, dyes and preservatives. Discuss home remedies with a doctor before trying them, and avoid repeated exfoliation that irritates the area.1

Which treatments can lighten underarms?

A doctor can select creams containing ingredients such as niacinamide, retinol, kojic acid or hydroquinone. For abnormally thick skin, urea or ammonium lactate can help dissolve the thickened outer layer. Dermatologists also use treatments such as chemical peels or dermabrasion. Laser treatment is an option in selected cases, rather than the usual first treatment for dark underarms.1

What if you also sweat excessively?

Excessive sweating can cause itching, inflammation and skin discoloration. Breathable, absorbent clothing such as cotton can improve comfort, and a clinician can help select an antiperspirant. If prescription antiperspirants fail, Botox is an option for excessive underarm sweating. Its effects are temporary and typically last about six months. This treats sweating, not pigmentation directly.67

How long does fading take?

For pigmentation left after irritation, general dark spot guidance gives a useful expectation: marks a few shades darker than your usual skin color often fade within 6 to 12 months after the trigger stops. Deeper pigmentation can take years. Treatment can speed fading. Acanthosis nigricans patches should fade over time when the underlying cause is treated.23

Stop a cosmetic product if it burns or stings. Never apply liquid bleach to skin. If your underarms will be exposed outdoors, apply tinted sunscreen with iron oxide and SPF 30 or higher before going outside, then reapply every two hours and after sweating or swimming. Do not stop a prescribed medicine because you suspect it causes darkening; ask the prescriber about alternatives.3

Can you remove dark underarms permanently?

Dark underarms can improve or clear, but permanent removal is not assured. Acanthosis nigricans often improves when its cause is treated, although some darkening can remain. Hyperpigmentation can return if new irritation or another trigger occurs. Continued control of the cause matters more than a product promising permanence, which is a large commitment for a cream.35