Darkened or discolored underarms are a common occurrence. Because of the variance in skin tone in the underarm area, some may feel uncomfortable wearing sleeveless shirts in public or bathing suits at the pool.
Darkened underarms also make it difficult for people to participate in social and physical activities like sports, hiking, etc.
This article will analyze the causes of dark underarms and explore the available remedies for underarm whitening.
Dark underarms are known as underarm hyperpigmentation in the medical profession.
The underarm skin is very delicate, which makes it prone to irritation. Irritation in any part of the skin in the body causes it to go through additional pigmentation. Take it as the body’s one of many coping mechanisms against irritation.
As a result of irritation, the underarm skin folds onto itself, hence resulting in a darker skin tone.
On the other hand, an unfavorable reaction to a product (perfume or deodorant) or a rash can cause skin discoloration, which is equally undesirable.
We are all familiar with deodorants and antiperspirants. In 2019, the global antiperspirant and deodorant market was estimated to be worth about 74.55 billion U.S. dollars, according to a study. 
A deodorant is a personal hygiene product applied to the body to prevent body odor. Meanwhile, an antiperspirant prevents sweating by reducing moisture on the skin where perspiration-causing bacteria live. Antiperspirants not only affect the odor of the body but also reduce sweating by affecting sweat glands.
A research study  proved the concentrations of metals in different kinds of underarm cosmetics. Although the estimated margin of safety indicated no considerable risk associated with the levels of the examined metals, it clearly demonstrated the urgent need for both national and international guidelines, and stringent regulations on metal impurities in cosmetic products.
Acanthosis nigricans is a hormonal-induced skin condition that causes darkness and discoloration in body folds or creases.
The primary cause of Acanthosis Nigricans is insulin resistance and hormonal disorder caused by ovarian cysts, underactive thyroids, or problems in the adrenal glands.
The person with Acanthosis Nigricans is characterized by dark, thickened skin in the underarms, groin, knees, and back of the neck.
Although present in some people, Acanthosis Nigricans is not the primary cause of darkened armpits for most people. Because it is a medical condition, this article will focus on other easily-curable causes.
Because of one or more of these reasons, 99% of the females have darkened armpits.
Just like a snake sheds, the human skin renews itself every 28 days. This is why the dark patch disappears after you stop wearing that tight shoe or an uncomfortable ring.
The primary reason for darkened underarms in females is skin irritation from shaving or exposure to chemical products via body deodorants and antiperspirants. Thus, these are the step-by-step action plan designed by a dermatologist to promote skin whitening:
You should put an effort into minimizing habits and routines that cause irritation in the underarm for any reason whatsoever. If you have a bad rash, follow doctor-recommended ointments to treat it quickly. Wear comfortable clothes that do not cause a rash in the underarm, or anywhere for that matter.
For some people, the use of deodorants may cause hyperpigmentation with or without a rash. Some deodorants contain sodium bicarbonate, an ingredient that can cause hyperpigmentation.
Consider switching to a hypoallergenic antiperspirant or a natural deodorant without sodium bicarbonate. Some may also choose to stay away from any artificial products applied or sprayed on the underarms.
Shaving without a shaving cream irritates the skin. Shaving cream softens and lubricates the hair, making shaving easier. It creates a lather that serves as a protective and moisturizing agent between the razor and the skin.
As a rule of thumb, allow the shaving cream to sit on the skin for fifteen to thirty seconds before shaving. You should also put an effort into replacing razor blades frequently. This helps prevent the usage of dull blades that are more irritating to the skin around the armpit.
Are you tired of waxing and shaving, only to see the hairs grow again after a few days? You might want to remove the unwanted body hair for a variety of reasons. Some feel like getting rid of them because it makes them look neat. Others want to remove them simply because they don’t feel like having them. (Which is totally reasonable.)
Waxing, threading, shaving, or even plucking (Yuck!) are some of the methods you have already tried. And they are never permanent solutions. You have to get back to the process again after a few weeks.
Diode Laser Hair Removal uses a mild form of the laser beam that is completely harmless to the human body. The laser beam destroys the hair follicles and prevents unwanted body hair from growing.
In each session, about 10 to 25 percent of body hair is removed. Thus, it takes about 5 to 7 sessions to get the best result.
Laser hair removal is an effective solution for underarm whitening. Skin irritation induced by shaving is a common cause of darkened armpits among men and women. By going through a laser hair removal procedure, the hair is completely removed from the armpit. This prevents further invasive procedures on the underarm in the future, and the underarm skin regains its natural tone because the skin replenishes itself after every 28 days.
A chemical peel is a procedure in which a chemical solution is applied to the skin to remove the top layers. The skin that grows back is smoother and lighter in tone.
Chemical peels containing trichloroacetic acid (TCA) have been proven effective to remove damaged skin cells. Thus, if the chemical procedure is performed on the underarms, positive results may be observed given that the client has already gone through a laser hair removal procedure before and avoids further erosion of the underarm skin.
Meanwhile, in the microneedling procedure, your dermatologist uses a special roller or device with needles to prick the skin. Microneedling is performed with a pen-shaped device known as Dermapen which uses fine needles that prick your skin with controlled intensity and depth. During the skin-pricking process, the skin produces more collagen in an effort to heal the small wounds from the needles. This stimulates new collagen production.
While chemical peels simply peel the outer layer of the skin, microneedling induces growth factors to promote a more effective replenishment of the underarm skin.
Prescription creams, ointments, and gels are available to lighten the underarm skin.
Your dermatologist may prescribe retinoid creams to thin and lighten the skin. Creams containing hydroquinone help lighten the color of the skin.
Dermatologists also use calcipotriene (Dovonex), a vitamin D-based cream to reduce pigmentation on the underarms. Meanwhile, topical antibiotics or antibacterial soaps minimize discomfort.
Many skin doctors recommend topical creams and antibiotics as they reduce skin discoloration and improve the appearance of the armpits.