Mandelic acid is an alpha hydroxy acid that's made from bitter almonds. Because of its anti-bacterial properties, this naturally-derived acid has a variety of medical and pharmacological uses. Pharmacologically, it can be combined with methenamine to produce mandelamine, a medication used to treat chronic urinary tract infections. Structurally, it resembles common antibiotics used to treat bacterial infections.
Like other alpha hydroxy acids, mandelic acid has skin benefits. It increases skin cells turnover by dissolving the tiny bonds that hold skin cells together, allowing dead skin cells on the surface of the skin to be sloughed off more quickly to reveal healthier cells underneath. This increased rate of sloughing thins the outermost layer of the skin called the stratum corneum. A thinner stratum corneum reflects light better and makes skin look smoother and more youthful. Mandelic acid and other alpha hydroxy acids also soften the appearance of fine lines and wrinkles and improve skin texture. At the same time, they lighten areas that have darkened in response to skin damage and sun exposure. Some alpha hydroxy acids also boost collagen production in the dermis of the skin. Collagen is a protein that gives skin its support and youthful firmness.
How does mandelic acid compare to other alpha hydroxy acids in terms of its skin anti-aging benefits? One of the most commonly used alpha hydroxy acids in skin products for mature skin is glycolic acid. According to a study published in the journal Cosmetic Dermatology, mandelic acid was as effective as glycolic acid for treating fine lines and wrinkles and other signs of sun damage. In fact, mandelic acid had some advantages over glycolic acid. It causes significantly less redness, flaking and skin irritation, which is a common problem with other alpha hydroxy acids.
People with deeply pigmented skin often have problems using alpha hydroxy acids because of the irritation they cause. This irritation can stimulate pigment-producing cells to produce more melanin, especially in people with a naturally dark complexion. This seems to be less of a problem with mandelic acid than with other alpha hydroxy acids. So, mandelic acid is a better choice for people with lots of pigment in their skin as well as those with sensitive skin who may experience excessive irritation with other alpha hydroxy acids.
Mandelic acid is used to target other skin problems including blemishes. Its anti-bacterial activity and capacity to increase sloughing of dead skin cells makes it a beneficial ingredient for acne sufferers. Some dermatologists combine salicylic acid with mandelic acid to use as a superficial skin peel to treat acne with good results. Acne sufferers can also get results at home using products that contain salicylic acid and mandelic acid at lower concentrations.
Due to its anti-inflammatory properties, mandelic acid may also be beneficial for treating rosacea, an inflammatory skin condition marked by facial redness and acne-like bumps. Most alpha hydroxy acids are too irritating for people with rosacea, but mandelic acid is better tolerated since it's less irritating.
Mandelic acid can be found in a variety of cosmetic and skin care products including cleansers, toners, moisturizers, eye creams, acne treatment products, skin lighteners and anti-aging treatment products. It appears to be safe in the quantities found in cosmetic and personal care products. The Environmental Working Group's Skin Deep Cosmetics Database classifies it as a low risk cosmetic ingredient. Alpha hydroxy acids are known to cause redness, flaking and skin irritation, but mandelic acid causes less irritation than other alpha hydroxy acids like glycolic acid and lactic acid, giving it additional benefits for people with sensitive skin.
All in all, mandelic acid has similar anti-aging benefits to other alpha hydroxy acids. It lightens darkly pigmented areas like sunspots and melasma, while reducing the appearance of fine lines and wrinkles. At the same time, it gives skin a smoother texture and more youthful appearance. Plus, it does it gently with fewer side effects than other alpha hydroxy acids. It's an excellent choice for people who have experienced irritation with other alpha hydroxy acids.