Mandelic acid is a type of gentle alpha hydroxy acid (AHA). It may help reduce acne, fine lines, and wrinkles and improve the appearance of uneven skin. As a person ages, skin renewal slows down, causing the skin to lose elasticity, discolor, and develop fine lines and wrinkles.

Chemical exfoliants, such as AHAs, are popular skin care ingredients that help loosen the top layer of older skin cells. These substances may improve the skin’s overall appearance and reduce visible signs of aging.

This article discusses mandelic acid, its benefits, and its side effects. It also explores how to add mandelic acid to a skin care routine.

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Mandelic acid is a type of AHA, which people use in skin care routines as chemical peels or exfoliants. The substance derives from bitter almonds.

Many cosmetic companies describe mandelic acid as a gentle AHA, so it may be suitable for people with sensitive skin or those who find other chemical exfoliants too strong for their skin.

In comparison with other AHAs, mandelic acid is a large molecule, about twice the size of glycolic acid. Mandelic acid also penetrates the skin much more slowly. This slow absorption may mean that it feels less irritating to the skin than other AHAs.

Mandelic acid offers a wide range of benefits for the skin. However, further conclusive research into mandelic acid is necessary to identify its properties and potential benefits.

Gentle on all skin types

Mandelic acid may be gentler than other AHAs and suitable for use by people of all skin types, especially those with sensitive and acne-prone skin.

Exfoliates all skin types

Like other AHAs, mandelic acid loosens the bonds that adhere the dead or old skin cells to the skin surface. This helps shed old, dryer skin cells to reveal new smoother skin cells.

Reduces the appearance of wrinkles and fine lines

In the process of chemical exfoliation, mandelic skin eliminates damaged and older skin cells and replaces them with newer, firmer skin cells. It may help the skin appear firmer and more elastic, reducing the appearance of wrinkles and fine lines.

Helps manage acne and clogged pores

Mandelic acid may help unclog pores, dissolve blackheads and comedones, and control sebum production.

Mandelic acid has antibacterial properties and may help remove acne-causing bacteria in the skin. It may also reduce inflammation and redness, which helps reduce the occurrence of breakouts, including cystic acne breakouts.

A 2019 study compared the effectiveness of 30% salicylic acid and 45% mandelic acid peels in treating mild to moderate acne vulgaris. It concluded that the acids were equally effective. However, the mandelic peel was safer and more tolerable than the salicylic acid peel.

The study also suggested that mandelic acid peels had fewer side effects and were more effective in treating inflammatory lesions.

Reduced hyperpigmentation and discoloration

Mandelic acid may help prevent different types of hyperpigmentation, including melasma.

A 2016 study compared glycolic acid and salicylic-mandelic acid to treat Indian people with melasma. It found that both types of acid are equally effective. However, the participants had a better tolerance for salicylic-mandelic acid.

Learn more about hyperpigmentation acne.

As with any skin product, there is a risk of side effects when using mandelic acid.

Mandelic acid may irritate a person’s skin. However, some research indicates that people tolerate mandelic acid well in comparison with salicylic acid.

Signs of skin irritation include:

People should apply sunscreen to reduce photosensitivity following a mandelic acid peel, as AHAs can increase the skin’s sensitivity to UV light.

Overusing mandelic acid may also lead to irritation and breakouts from over-exfoliation.

A person should also avoid getting mandelic acid in their eyes, as it may cause irritation or damage.

People should consider conducting a patch test before using products with mandelic acid for the first time. A person may also consider seeking further advice from a doctor or dermatologist.

Several skin care products contain mandelic acid, and these can include facial cleansers to chemical peels. It is also available in different concentrations, depending on the product. The manufacturer should provide instructions on using these products.

Generally, people can use facial serums and cleansers daily. However, they should only use more potent products, such as peels, no more than once or twice a week.

People may prefer to add mandelic acid to their nighttime routine because AHAs can increase the skin’s sensitivity to light. They can apply it after cleansing and before moisturizing. Similarly, masks and peels are most suitable for application to the skin after washing. A person should allow the mask or peel to sit for a few minutes before washing it off.

Individuals need to consider doing a patch test before using mandelic acid for the first time to see if they can tolerate it. People should start at lower concentrations and apply it no more than once a week. A person may consider speaking with a doctor or dermatologist before increasing the acid concentration or the frequency of application.

A person should also avoid using it with other chemical peels and exfoliants, such as retinol, other AHAs, and beta hydroxy acids (BHAs). Overusing chemical peels and exfoliants may lead to over-exfoliation, which can cause skin sensitivity and breakouts. A person can consult a doctor or dermatologist for further advice.

Acids may also dry the skin. After using mandelic acid to help soothe and moisturize the skin, a person can apply hydrating products, such as moisturizers.

A person may wish to consider the following alternatives to mandelic acid:

  • Lactic acid: Another AHA with similar benefits to mandelic acid.
  • Azelaic acid: People use this acid primarily to treat rosacea and acne. It has antimicrobial and anti-inflammatory properties.
  • BHAs, such as salicylic acid: These are slightly larger molecules than AHAs, so they may be less irritating. BHAs may be more suitable for people with oily, acne-prone skin and may help manage clogged pores, whiteheads, and blackheads. Salicylic acid derives from aspirin.

Learn more about AHAs and BHAs.

People should consider speaking with a doctor or dermatologist to help choose products and ingredients suitable for their skin.

Mandelic acid may be suitable for people with sensitive skin. Skin experts believe it has fewer side effects and irritates the skin less than other AHAs.

However, a person should consider doing a patch test before trying mandelic acid for the first time. People should also make sure that they use safe concentrations and sufficient intervals between applications.

A person should consider speaking with a doctor or dermatologist before adding mandelic acid to their skin routine. Dermatologists can assess a person’s skin better, recommend the best products according to their skin type, and educate them on proper use.