Alpha Hydroxy Acids, commonly known as AHAs, have been gaining popularity in the skincare industry, particularly for their effectiveness in treating dark spots. AHAs are water-soluble acids derived from sugary fruits. They help peel away the surface of your skin so that new, more evenly pigmented skin cells may generate and take their place.

There are several types of AHAs, including glycolic acid, lactic acid, and mandelic acid, among others. Each type has its unique benefits, but they all work towards the common goal of promoting skin cell turnover and renewal.

Glycolic acid, derived from sugar cane, has the smallest molecular size among AHAs, allowing it to penetrate the skin deeply and quickly. This makes it highly effective for treating dark spots, fine lines, and other signs of aging.

Lactic acid, derived from milk, has a larger molecular size, which results in slower skin penetration. It's milder than glycolic acid and is excellent for sensitive skin. It also helps in lightening dark spots and improving the skin's natural moisture factor.

Mandelic acid, derived from bitter almonds, has the largest molecular size, which makes it the gentlest AHA. It's excellent for treating dark spots, especially in individuals with sensitive skin or those who have had adverse reactions to other AHAs.

AHA serums work by exfoliating the skin's surface, promoting faster cell turnover, and revealing a new layer of skin. This process helps reduce the appearance of dark spots, as the pigmented cells are shed away faster.

However, while AHAs are effective, they can make your skin more sensitive to the sun. Therefore, it's crucial to use a broad-spectrum sunscreen daily when using AHA serums to protect your skin from harmful UV rays and prevent further darkening of the spots.

In conclusion, AHA serums can be a powerful tool in your skincare routine for tackling dark spots. However, it's essential to use them wisely and always in conjunction with a high-SPF, broad-spectrum sunscreen.