How to Get Rid of Dark Underarms in 3 Steps

February 06, 2026

By: Truly Beauty

Since they won’t go away on their own, the only way to get rid of dark underarms for good is with brightening, melanin-inhibiting skincare products.

Underarm darkness can also be a sign of something serious. Ahead, we show you what causes dark underarms, signs it might be something serious, and how to lighten dark underarms at home.

Why Are My Underarms Dark?

Dark underarms are very common, affecting over 70% of the population, especially those with higher melanin levels. Most commonly, they’re caused by friction, hormonal changes, shaving, and skin irritation from deodorant.

According to dermatologists, dark underarms may also be a sign of a medical condition. Known as Acanthosis nigricans, it is a skin pigmentation disorder that’s associated with insulin resistance, obesity, type 2 diabetes, or PCOS.

The most common causes of dark underarms are:

• Genetics
• Post-inflammatory hyperpigmentation
• Allergic contact dermatitis or a rash
• Sweating
• Irritation from shaving, deodorant, antiperspirant
• Friction from tight clothing
• Polycystic ovarian syndrome (PCOS)

If you notice underarm hyperpigmentation along with other symptoms like weight gain, irregular menstrual cycles, and abnormal hair growth, consult your doctor to get a diagnosis.

How to Get Rid of Dark Underarms

While there are lots of at-home remedies that claim to help with your dark underarms, dermatologists suggest starting with products specifically designed to treat discoloration. We recommend giving one or more of these methods below a try to help brighten your underarm area.

1. Physical + Chemical Exfoliation

Without regular exfoliation, dead skin cells build up which can lead to duller, darker underarms and increased pigmentation. To effectively remove this buildup, use a cleanser that combines both physical and chemical exfoliation like Truly’s 24K Gold Black Soap Cleanser.

24K Gold Black Soap Luxury Impurity Cleanser

Impurity-Erasing Exfoliating Cleanser

Add to Bag $32

Buy at Sephora Buy at Boots

This gentle sugar scrub contains salicylic acid, working on a molecular level to dissolve dead skin cells while manually buffing away the loosened dead cells and surface impurities to reveal brighter, more even-toned skin.

A 2015 study found salicylic acid to be highly effective at reducing the appearance of dark patches when used consistently over 2-3 months.

2. Brightening Deodorant

To get rid of dark armpits, upgrade your deodorant to one that not only combats odor, but helps fade discoloration like Truly’s Unicorn Fruit Deodorant.

Unicorn Fruit Skin Brightening and Smoothing Deodorant

Aluminum-Free Brightening Deodorant

Add to Bag $18

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Clean and aluminum-free, this deodorant naturally eliminates odor-causing bacteria to reduce BO while visibly brightening dark underarms with a blend of niacinamide and mandelic acid. Plus, it smells delicious - like cotton candy and raspberry.

A study in the Journal of Drugs in Dermatology found mandelic acid to be extremely effective at treating melasma and post-inflammatory hyperpigmentation.

3. Hyperpigmentation Treatment

Finally, you definitely want to use a specific treatment for dark spots on the underarm skin. This will help inhibit melanin production while brightening darkness at a deeper level for more even-looking skin.

Jelly Booster Pigment Body Potion

Targeted Brightening + Discoloration Treatment

Add to Bag $33

Buy at Sephora Buy at Boots

A bestseller is Truly’s Jelly Booster Pigment Body Potion. Light and refreshing, it visibly brightens dark patches and evens skin tone while moisturizing sensitive skin with a rejuvenating blend of pomegranate extract, vitamin B12, and spirulina.

Tips for Preventing Dark Armpits

Now that you’ve got the best products for dark underarms, you want to make sure they don’t come back. Here are some ways to keep your underarms even and bright.

1. Avoid repetitive friction: Try waxing less and if you shave, make sure you’re using a high quality shaving cream to prevent friction and darkness. Alternatively, consider laser hair removal for longer lasting effects. Avoid wearing tight clothing and opt for looser, more breathable pieces to prevent friction-induced dark armpits. 

2. Exfoliate weekly: Use a gentle scrub to remove the buildup of dead skin cells and naturally brighten the underarm area. You don’t need to do this daily, especially if you have sensitive skin, as this may irritate the skin and worsen discoloration.

3. Avoid irritating deodorants: Switch to an aluminum free deodorant infused with natural, clean ingredients to avoid irritating your underarms.

4. Moisturize: Keep your underarms hydrated with a gentle, fragrance-free lotion or serum to soothe dry skin and prevent friction, which can lead to underarm dark patches.

5. Avoid home remedies: Lemon juice and baking soda might be good natural remedies for underarm darkness but they can also irritate and dry out your skin, making them even darker.

6. Treat the underlying skin condition: If you have a skin condition like psoriasis or dermatitis, make sure you treat it properly in order to brighten the armpit skin.

FAQ: Fixing Dark Underarms

What Is the Fastest Way to Get Rid of Dark Underarms?

The fastest way to get rid of dark underarms is by combining regular exfoliation with targeted brightening products that inhibit melanin production. Dermatologists in the U.S. recommend ingredients like salicylic acid, mandelic acid, and niacinamide for visible results within 4–8 weeks when used consistently.

How Long Does It Take to Lighten Dark Underarms?

Most people notice brighter underarms within 4–8 weeks of consistent treatment. For deeper hyperpigmentation caused by friction, shaving, or hormonal changes, it may take up to 12 weeks. Results depend on skin type, the cause of discoloration, and product use.

Can Shaving Cause Dark Underarms?

Yes. Shaving is one of the most common causes of dark underarms, especially in people with sensitive or melanin-rich skin. Razor friction and micro-cuts can trigger post-inflammatory hyperpigmentation. Using a gentle shaving cream or switching to waxing or laser hair removal may help prevent underarm darkening.

Are Dark Underarms a Sign of a Medical Condition?

Sometimes. While dark underarms are often caused by irritation or friction, they can also be a sign of acanthosis nigricans, a skin condition linked to insulin resistance, type 2 diabetes, obesity, or PCOS. If underarm discoloration appears suddenly or worsens alongside other symptoms, consult a dermatologist or healthcare provider near you.

Do Aluminum-Free Deodorants Help Lighten Dark Armpits?

Aluminum-free deodorants can help prevent further darkening by reducing irritation and clogged pores. Deodorants with AHAs or niacinamide, which help fade discoloration while controlling odor.

Are Brightening Products Safe to Use on Underarms?

Yes, when formulated for sensitive skin and used as directed. Dermatologists recommend avoiding harsh home remedies like lemon juice or baking soda, which can worsen irritation and hyperpigmentation. Always patch test new products, especially if you have sensitive skin.

Can Dark Underarms Come Back After Treatment?

Yes, dark underarms can return if the underlying cause isn’t addressed. Continued friction, shaving, tight clothing, or irritating deodorants may trigger pigmentation again. Maintaining a gentle skincare routine and using brightening products regularly can help prevent recurrence.

When Should I See a Dermatologist for Dark Underarms?

If your underarm pigmentation does not improve after 8–12 weeks of treatment, or if it’s accompanied by symptoms like itching, thickened skin, or sudden color changes, it’s best to see a board-certified dermatologist for personalized treatment options.

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