Acid-based products and treatments are more than just a fad. They continue to impress with their ability to help reverse and slow down the aging process. As people age, their skin loses its ability to quickly rid itself of old skin cells. This leads to a thickening of the epidermis and a loss of elasticity. Hydroxy acids, which include alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs), treat a wide range of skin issues, such as acne, hyperpigmentation, and wrinkles. “AHAs and BHAs offer numerous benefits to the skin, one of the most primary being rejuvenation and regeneration,” says Rhonda Allison, founder and CEO of Rhonda Allison Cosmeceuticals. “These acids are also effective in treating acne, balancing oil production, reducing pigmentation, brightening, firming, toning, and scavenging free radicals. Depending on the type of AHA, they may also deliver important hydration to the skin.”
According to Elisabeth Nehme, international brand ambassador and master educator at [ comfort zone ], AHAs are water-soluble, so they offer smoothing, renewing, and plumping benefits to the skin. Meanwhile, BHAs are lipophilic (oil soluble), so they offer exfoliating, antiseptic, and anti-inflammatory properties and are very effective in treating acneic skin and skin that is oily and congested. “BHAs dissolve in sebum and are therefore able to enter the pore and clean debris from it,” says Charlene DeHaven, M.D., clinical director for Innovative Skincare, maker of IS Clinical products.
AHAs, which are chemical compounds derived from fruit, milk, and sugar, are the most common hydroxy acids found in skincare products. They work by breaking down the sugars in the skin, which then causes the cells of the epidermis to loosen and slough off, making room for the growth of new ones. “AHAs gained popularity for their ability to penetrate the stratum corneum more rapidly,” says Allison. “They seep into cells of the upper layers of the epidermis and loosen the glue-like substances (ceramides) that hold skin cells together, stimulating cellular regeneration.” Meanwhile, BHAs have a larger molecule size than AHAs, which enable the acids to stay on the surface of the skin and more effectively penetrate and exfoliate within the pore. “The larger molecule size also produces less irritation than AHAs, making it a welcome alternative for sensitive skin,” says Allison.
Perfect Types
According to Robin Carmichael, president and chief operating officer of Helix BioMedix, AHAs help to reduce fine lines and wrinkles and can also help lighten the skin and fade dark spots. “They help stimulate collagen production, which in turn, helps firm the skin,” she says. “AHAs also act as humectants to help improve moisture content in the skin.” There are several AHAs commonly found in skincare, such as glycolic acid (derived from sugar cane), lactic acid (derived from milk), malic acid (derived from apples), mandelic acid (derived from bitter almonds), phytic acid (derived from seeds and grains), and tartaric acid (derived from grapes). “Most are water-soluble, meaning that the acid easily changes the skin’s pH and causes an instant burst in exfoliation,” says Tara Damiano, global curriculum developer at Dermalogica and The International Dermal Institute. “They exfoliate from the inside out, as AHAs work primarily by dissolving the desmosome connections between the corneocytes in the lower area of the stratum corneum.”
Lactic acid is considered the most gentle and effective type of AHA. According to Damiano, it is a keratolytic agent, meaning that it softens and loosens the desmosomes, which are intercellular junctions, and breaks down their bonds. “Its molecular size is larger than that of glycolic, making its penetration rate slower, so it’s considered gentler—yet it’s often even more effective,” she says. Lactic acid also boosts glycosaminoglycans, which maintain and support collagen and elastin, and epidermal barrier lipids, which keep skin strong and slow melanin synthesis to fight hyperpigmentation. Glycolic acid is the smallest AHA in size and penetrates the skin easily, which can sometimes result in irritation. “It’s keratolytic, as it dissolves the keratin bonds between the corneocytes,” says Damiano. “Glycolic acid is most commonly used to help treat oily and acneic skin, because it effectively loosens keratinous plugs in the follicle.” The Glycolic Repair Facial (starting at $135, 60 minutes) at Pacific Waters Spa at the Hyatt Regency Huntington Beach Resort & Spa (CA), for example, includes a glycolic acid treatment that works to reduce fine lines, acne, hyperpigmentation, and dryness and also includes a glycolic-peppermint hand and foot treatment.
According to Carmichael, malic acid is generated during fruit fermentation and is found in wine, as well. “Its skin penetration and exfoliation properties are balanced by its ability to be a skin humectant, which makes it ideal for sensitive skin,” she says. Meanwhile, mandelic acid has been found to be helpful in fading hyperpigmentation, fighting blemishes, and rejuvenating aging skin. “It is a larger molecule than glycolic acid, and this allows for more gentle skin penetration,” says Carmichael. “Its chemical structure is similar to other well-known antibiotics and thus provides some antibacterial benefits.” At Onzen the Spa (Albany, CA), clients with sensitive skin can opt for the Mandelic Acid Peel ($100, 60 minutes), which is gentle and helps treat photo-aging and pigmentation concerns.
BHAs have a larger molecular structure than AHAs. The most common BHA used in skincare is salicylic acid, which occurs naturally in plants like sweet birch, willow bark, and wintergreen leaves. “The primary BHA used in skincare is salicylic acid, which helps to break apart dead cells, has anti-acne properties, and is also mildly anti-inflammatory,” says Carmichael. “As salicylic acid is oil-loving and can get deep into the sebaceous follicle, it is the ideal choice for clients with oily and acne-prone skin.”
According to Nehme, BHA products and treatments are matched perfectly with those that purify and feature ingredients such as algae, green clay, and vitamin C, like the Purity Peel ($125, 60 minutes) at Spa Mizan (Lafayette, LA), which includes salicylic acid to gently exfoliate the skin, ascorbic acid to calm and heal, and retinol acid to increase the production of collagen and elastin.
The Right Choice
AHAs and BHAs are generally tolerable by most skin types, but their effectiveness varies based on the client, skin issue, and skin type. To ensure that the proper hydroxy acid is used on a client’s skin, Annet King, director of global education at Dermalogica and The International Dermal Institute, suggests that the chemical exfoliation step be performed after a double cleanse and thorough skin analysis to determine the client’s skin type and condition. “After choosing the correct formula to address the client’s concerns and desired outcome, follow the manufacturer’s directions,” says King. “Today, there are so many different products available, from oil-based to setting to leave-on. Some can also be used with or before or after exfoliation tools for deeper, more intense results.”
Also, according to Allison, the efficacy of hydroxy acid treatments and products is not solely based on the percentage in the formula, but rather the pH and grade of the acid. “The lower the pH, the more intense the acid,” she says. “Always opt for the highest grade and a pH of 2.5 to 3 to see the best results. AHAs and BHAs may also be prescribed as part of homecare to further support the rejuvenating process.”
Chemical peels are some of the most common and effective treatments that contain AHAs and BHAs, because they help rejuvenate skin with little to no downtime, so Fabienne Lindholm, executive director of education, North America at Babor, recommends that spas offer them in a series of treatments or as an add-on to a traditional facial to help clients receive the best results possible. Post-treatment, Nehme suggests applying a solution to lower the pH of the skin, as these acids work best in an acidic environment. “After the treatment, the pH must be restored, and the skin nourished with hydrating serums and protective moisture,” she says.
Warning Signs
While acid-based treatments and products can produce remarkable results on most clients, there are contraindications to keep in mind. For example, skincare professionals can sometimes be overly aggressive in resurfacing on a client with an underlying inflammatory concern, such as uncontrolled rosacea. “Many treatments used in acne are also used for rosacea, including the AHAs and BHAs,” says DeHaven. “In this situation, the rosacea can flare due to unregulated inflammation related to the AHA or BHA.” Also, in the aging client, resurfacing treatments that are too aggressive can result in an over-processed look to skin, which includes thinner skin; telangiectasia, a condition in which small dilated blood vessels appear on the skin; and irritation. “Metabolism decreases with aging, and the regenerative capacity of skin is slowed or impaired,” says DeHaven. “The aging client may have difficulty replacing cells lost from very aggressive resurfacing.”
Another factor to keep in mind is that some ethnic groups have particularly sensitive skin, including clients of Asian ethnic background. Therefore, concentration of the acid must be chosen depending on each client’s particular characteristics and results desired. To ensure that the proper acid and dose is used, it is crucial for spas to conduct a thorough intake evaluation for all clients that considers ethnic background, individual sensitivities to topicals, underlying skin conditions, and personal preferences for downtime, says DeHaven. Also, prior to performing an acid-based peel, a patch test on the back of the neck will determine the tolerance level of the client.
In addition, pregnant and breastfeeding women should avoid salicylic acid treatments and products, as well as clients with allergies or sensitivities to certain ingredients (milk in lactic acid or nuts in mandelic acid, for example). Also, it’s important to find out if clients are using any medications that will alter their skin physiology and the frequency of use of these products (such as Accutane) or have active cold sores, according to King. “If clients are using homecare exfoliants like hydroxy acids or vitamin A derivatives, they should stop two-to-three days before the treatment if it is the same brand as you are using,” says King. “If it is another brand, stop using a week before, as you don’t know how ingredients will react together.” She also advises spa professionals to avoid performing any type of exfoliation on sunburned or irritated skin, or on skin that has been waxed within the past 24 hours and on areas that might be impaired (from continual blowing of the nose or dryness from cold medications, for example). According to Nehme, clients with hyperpigmentation and sunspots could see an increase in discoloration, and all acid treatments and products can increase sun sensitivity. Also, because skin and emotions are linked, skin sensitivity may increase in times of extreme stress.
Because of the many contraindications, Nehme believes it is imperative for you to encourage clients to ask questions and discuss the treatment with the spa professional during a pre-treatment consultation in order to create a treatment and homecare plan that is harmonized with the client’s lifestyle, past and current skincare programs and treatments, and goals and expectations. Says Nehme, “We believe that moderate use is best, meaning that we have a cycle of skin renewal followed with a cycle of nourishment and restoration—balance is everything.”
Clients are sure to fall hard for these acid-based products.
1. Amber Products Blemish Defense Peel: Formulated for oily and problematic skin, this spot treatment features certified organic olive oil that fights acne-causing bacteria in pores while malic acid promotes cell renewal. www.amberproducts.com
2. Biologique Recherche Lotion P50: Stimulate cellular renewal and smooth the skin with this gentle, balancing exfoliator containing AHAs and BHAs, including citric, lactic, and malic acids, that purify, clean, and recondition the skin. www.biologique-recherche.com
3. CelleClé Skincare MicroSmooth AHA Resurfacing Serum: Speed cell renewal and plump fine lines with this hydrating serum filled with glycolic, lactic, and mandelic acids and biofermented saccharides that calm stressed skin. www.cellecleskincare.com
4. Cinq Mondes Phyto-Peeling Lotion: Combined with natural fruit acids and glycolic acid, this cooling toner optimizes cell renewal, reduces blemishes, refines texture, and illuminates the complexion on a daily basis. www.cinqmondes.com
5. Circadia Amandola Milk Cleanser: Naturally brighten the skin with this gentle cleanser filled with AHAs, such as lactic and mandelic acids, along with milk protein, vitamins, and wheat gluten that help retain moisture. www.circadia.com
6. HydroPeptide Clarifying Toner Balance Control Pads: These pads are soaked with renewing AHAs and a pore-cleansing peptide to help restore healthy skin. www.hydropeptide.com
7. Ilike Organic Skin Care Botanical AHA Peel: Formulated to combat acne, prevent breakouts, and fade sun damage and hyperpigmentation, this lactic acid peel eliminates dead skin cells while lemon oil acts as a natural astringent to minimize large pores and reduce excess shine. www.szepelet.com
8. Le Mieux Vita-C Clear Skin Pad Solution: These triple-action exfoliant pads featuring citric, glycolic, lactic, and tartaric acids gently resurface, brighten, and treat visible signs of aging. www.lemieuxcosmetics.com
9. Natura Bissé Facial Cleansing Gel + A.H.A.: Efficiently cleanse and eliminate excess oil and impurities from pores while gently renewing skin’s texture with this AHA-based cleanser. www.naturabisse.com
10. Pevonia Vitaminic Concentrate: Smooth wrinkles and even skintone with this micro-emulsified concentrate containing mandarin orange essential oil, squalane, and vitamins A and E, which help to brighten and regenerate skin. www.pevoniapro.com
11. Phytomer Resurfacing Peel: Improve the appearance of all skin types affected by sun exposure and signs of aging with this peel formulated with marine AHA derived from red algae. It helps to eliminate dead cells on the skin’s surface. www.phytomerusa.com
12. Sothys Paris Glysalac Dermobooster: Increase micro-exfoliation with this resurfacing skin booster containing glycolic and salicylic acids, which encourage cell renewal, resulting in smooth, radiant skin. www.sothys-usa.com