Hyaluronic acid is primarily known for its hydrating and plumping properties, making it a popular ingredient in skincare products. However, when it comes to dark underarms, hyaluronic acid may not be the most effective solution.

Dark underarms can be caused by various factors such as hormonal changes, friction, shaving, or the use of certain deodorants. To effectively address this concern, it's essential to understand the underlying cause.

Hyaluronic acid primarily works by attracting and retaining moisture in the skin, improving hydration levels and promoting a smoother appearance. While it can help with overall skin health, it does not have a direct effect on lightening or reducing the darkness of underarms.

To address dark underarms, it's advisable to consider other ingredients or treatments that specifically target hyperpigmentation or skin discoloration. Ingredients such as arbutin, kojic acid, niacinamide, or licorice extract are known for their skin-lightening properties and may be more suitable for this concern.

However, it's important to note that individual results may vary, and it's always best to consult with a dermatologist or skincare professional who can provide personalized recommendations based on your specific skin type and concerns.