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How Active Ingredients Act on Skin

Common Ingredients in Skin Care Products and What They Do

It is easy to feel overwhelmed while shopping for skincare products. So many products promise results like “anti-aging,” “radiant skin” or “no more acne” on their front labels. However, if you really want to find out how a product is going to work on your skin, flip it over and look at the active ingredients on the back. 

“The active ingredient is the component of your skincare product that is supposed to target a specific skin care concern,” says Northwestern Medicine Dermatologist Walter J. Liszewski, MD. “You often don’t need the most expensive skin care product on the market so long as you pay attention to the active ingredients and know what they do to your skin.”

Here are common active ingredients in skin care products and how they work on your skin.

Beta-Hydroxy Acid (Salicylic Acid)

Targets: Acne

Beta hydroxy acid is an exfoliant that peels away the top layers of your skin. It can help prevent acne and get rid of skin discolorations caused by acne. In chemistry, the pH scale measures how acidic or basic a liquid is. The more acidic your skincare product is, or the higher concentration of acid it has, the deeper it will penetrate your skin.

Some of these acids are available over-the-counter, but your dermatologist may prescribe stronger solutions based on your skincare needs.

“Dermatologists may recommend salicylic acid in over-the-counter exfoliators or superficial chemicals peels you would get at a medical spa. Stronger acids used in medium-to-deep peels should only be performed by a dermatologist who knows how to handle acidic solutions safely,” says Dr. Liszewski.


Targets: Hyperpigmentation

Your body makes hydroquinone naturally, and it helps reverse or lighten the appearance of dark spots. When used topically in a cream or serum, it can help with hyperpigmentation. In this condition, areas of skin become darker than others due to an overproduction of melanin. Melanin is a pigment that is responsible for your skin tone. The more melanin you have, the darker your skin. Melanocytes are molecules that make melanin. Hydroquinone works by decreasing the amount of excess melanin in the skin.


Targets: Acne, signs of aging and hyperpigmentation

Retinoids are derived from vitamin A. They help stimulate the formation of collagen, which is a protein that serves as a building block for your skin, hair, bones, muscles and ligaments. Retinoids help the skin grow more evenly. This helps prevent acne by unclogging pores and preventing dead skin cells from clogging pores. Retinoids also help reduce the risk of new acne scars and can help minimize the appearance of existing acne scars, too.

Retinoids can help with hyperpigmentation by reducing the amount of melanin in the surface of the skin.

Retinols are similar to retinoids. They are precursors that are converted into retinoids in the skin.

“Retinoids are often more effective than retinols, but they can be more irritating,” says Dr. Liszewski. “It may take a longer time to see results from retinols versus retinoids.”

Hyaluronic acid

Targets: Signs of aging

Hyaluronic acid is a naturally occurring compound in the skin. It helps to store water and give the skin volume and shape.

“Dermatologists use hyaluronic acid in cosmetic fillers to correct the appearance of wrinkles and the loss of facial volume as we age,” says Dr. Liszewski. “Most topical hyaluronic acid products are more gimmick than an effective treatment.”  He explains, “Hyaluronic forms large chains, and these are often too large to penetrate the skin when applied topically.”

However, when a dermatologist injects it into your skin with a needle, hyaluronic acid can be quite helpful in reducing signs of aging. Though, its benefits may only last several months. 

Vitamin C

Targets: Sun damage

Vitamin C is an effective antioxidant that prevents sun damage and photoaging, or aging caused by ultraviolet (UV) light. It does this by getting rid of “free radicals” caused by sun exposure, or particles that can damage the cells in your body. Vitamin C also promotes collagen production.

“Vitamin C has become quite trendy as an anti-aging product. However, it is rapidly degraded, or broken down, by UV light,” says Dr. Liszewski. “Many vitamin C serums or products may not use stabilizers to ensure the vitamin C lasts for several hours.”

Ultimately, vitamin C serums can be effective, but only if the product is properly made with stabilizer ingredients to preserve vitamin C.

Benzoyl Peroxide

Targets: Acne

Benzoyl peroxide is an effective antibiotic that can kill bacteria on the skin that causes acne.

“Benzoyl peroxide is fantastic at preventing and treating existing acne lesions,” says Dr. Liszewski. However, he cautions that, “at higher concentrations benzoyl peroxide can be irritating in certain individuals.”

Benzoyl peroxide creams have the potential to bleach clothing. Benzoyl peroxide soaps are less likely to do this, but it is possible.

Talk to Your Dermatologist

Talk to your dermatologist about which active ingredients you should use. Before you try a new product, apply it only to a small patch of skin to see if it irritates your skin.

If you do not see results with a certain product, you may need to use the product differently or try a new one. Your dermatologist can guide you to ensure that your skincare routine safely meets your skin’s needs.

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