Wednesday, 08 January 2020 11:00

Layer by Layer: A Guide for Layering Chemical Peels, Enzymes, and Scrubs

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Innovative technological advances have afforded the skin care professionals multiple exfoliation options to help achieve their clients’ skin care goals. New protocols have been developed to pre-exfoliate the skin prior to chemical exfoliation by incorporating enzymes or scrubs to the professional treatment, while others mix peel solutions or introduce new layering techniques.


Chemical peels utilize various ingredients to exfoliate damaged skin in the outer layers. Chemoexfoliation addresses client concerns related to acne, aging, pigmentation, rough texture, and uneven skin tone and can provide temporary relief from sensitive skin conditions, including rosacea, eczema, and psoriasis. Common chemical peel ingredients are alpha hydroxy acids, beta hydroxy acids, poly hydroxy acids, TCA peels, retinoids, resorcinol, and low dosages of phenol. Exfoliation is also achieved by using enzymes such as bromelain, papain, and pumpkin, amongst many others. One of the latest innovations in advanced next-generation technologies introduces the skin care professional to the use of peptides for exfoliation. Lastly, scrubs, including the newer microdermabrasion polish scrubs, include ingredients like alumina, silica, or sea salt for the “grit” to buff and polish the skin.


This article explores enhancing current exfoliation techniques by the use of mixing and layering alpha hydroxy acids, beta hydroxy acids, poly hydroxy acids, bionics, TCA peels, retinoids, peptides, enzymes, and scrubs in the treatment room.




The professional has many forms of exfoliation for treatment options. They must follow the manufacturer’s protocols to provide a safe and effective treatment for their clients. Be sure that the client tolerates all exfoliation methods individually before combining them. Most importantly, stay within the scope of practice as defined by your state board regulations. Many states still follow The Esthetic Manufacturers and Distributors Alliance of the American Beauty Association (EMDA) guidelines that state that an aesthetician can only use an alpha hydroxy acid that is less than 30% and a pH of greater than 3.0. Some states will not allow certain acids to be used on the skin.


Before purchasing acids, check with the state board to be sure that the spa is allowed to use them. Keep in mind that statutes can change at any time, so stay current and informed. Next, be sure that the spa’s insurance carrier covers all ingredients and modalities that are used. Lastly, become familiar with any contraindications or complications that may arise with any products that will be used. For example, if a client is using Retin-A, Renova, or another retinoid, have the client discontinue use 48 to 72 hours prior to treatment. If using salicylic acid, find out if the client has aspirin allergies; aspirin (acetylsalicylic acid) is a close relative to salicylic acid, which could cause severe reactions.


With any chemical peel, which is a controlled burn, unpredictability and risks such as infection and scarring, thinning of the dermis or epidermis, hyperpigmentation, and long-term erythema (redness) are possible. For these reasons, manufacturer training is a must before application. Never try to become a cosmetic chemist mixing your own formula. Use formulations that have been tested by the manufacturer for safety and efficacy.




Alpha Hydroxy Acid: Alpha hydroxy acids, often called the fruit acids, include glycolic, lactic, malic, mandelic, tartaric, and citric acids. They aid in exfoliation by dissolving the fibrous bonds (desmosomes) that hold skin cells together in the epidermis. They work from the lower layers of the skin upward, assisting the desquamation process. Alpha hydroxy acids are water-soluble and are used to treat fine lines and wrinkles, areas of dryness, uneven pigmentation, and acne.


Beta Hydroxy Acid: Beta hydroxy acids have a different molecular structure than alpha hydroxy acids, so they function differently. Alpha hydroxy acids work on clusters of cells, while beta hydroxy acids can focus on individual cells. A beta hydroxy acid works from the surface downward. Beta hydroxy acids are lipid-soluble, making them a practical choice for oily skin types. The most common form of beta hydroxy acid is salicylic acid derived from salicin, which is closely related to the main ingredient in aspirin, making it essential to determine whether or not a client is allergic to aspirin before using this ingredient in any part of a treatment or post-care. Other common beta hydroxy acids include derivatives of salicylic acid, which include salicylate, sodium salicylate, willow extract, beta hydroxybutanoic acid, and trethocanic acid. Because beta hydroxy acids are anti-inflammatory, they tend to be less irritating than an alpha hydroxy acid.


Poly Hydroxy Acid and Para-hydroxybenzoic Acid (Bionics): Polyhydroxy acids, like gluconic acid and gluconolactone, fall under the alpha hydroxy acid category but are milder than alpha hydroxy acids and non-irritating, making them an alternative option for acne formulations and an excellent choice for sensitive skin conditions. Poly hydroxy bionic acids like maltobionic or lactobionic acids have a similar molecular structure except that there is an additional sugar molecule attached to the poly hydroxy acid. Both poly hydroxy acid and bionics function similarly to an alpha hydroxy acid except they:


  • are less irritating
  • do not sting or burn
  • provide the additional benefits of hydration
  • function as antioxidants and metal chelators that fight oxidative stress
  • can enhance the skin’s barrier functions
  • are matrix metalloproteinase inhibitors (MMPIs) (they inhibit the destructive enzymes that can negatively impact the extracellular dermal matrix)
  • have a larger molecular size allowing for slower penetration and easier control


TCA: Trichloroacetic acid treats fine surface wrinkles, pre-cancerous growths, superficial blemishes, and pigment problems like melasma, blotchy skin, and sun damage. TCAs can be superficial at 6%, medium-depth at 20% to 30%, and deep above 40% up to 100%.


Phenol: Phenol is the strongest of the chemical solutions and produces a deep peel depending on the percentage and whether it is part of a blended solution. For example, a 2% phenol would be superficial. Phenol can hypopigment a treated area. The level of skin pigmentation may be a determining factor as to whether or not this is an appropriate treatment for a client.


Resorcinol: It is a precursor to phenol, which contributes to flaking when added to a chemical peel blend.


Retinoids: The primary purpose of a retinoid is cell turnover rather than desquamation. However, when used in any exfoliating procedure, retinoids may lead to pronounced flaking. Retinoids and vitamin A derivatives can range from very mild (retinal palmitate) to prescription level retinoic acid (tretinoin).   


Retinoids from mildest to strongest:


  • retinoids image
  • peel depth image


Sample acidic comparison chart (alpha hydroxy acids to beta hydroxy acids to TCAs) – weakest to strongest:


  • Peel Penetration Sample Chart image




Enzymes function as catalysts; they accelerate a chemical reaction. In skin care, an enzyme is activated by water, which causes the keratin proteins within the skin to break apart, allowing the dead skin cells to accompany the enzyme during its removal. Enzymes alone can be an excellent option for a teenager or any client who does not want to experience post-treatment flaking.


Additionally, any treatment protocol that layers enzymes with acids is an effective option that generates deeper acid penetration without the irritation of using a stronger percentage of any given peel solution. Just a few of the many common enzymes used in skin care are bromelain (pineapple), papain (papaya), pumpkin, blueberry, apple, phytase, and passionfruit.  


Passionfruit digests skin cells on the surface of the skin and inside the hair follicle. It not only digests superficial dead cells but is a rich nutrient and antioxidant that has over 104 nutrients, a delicious scent, is very useful for purging congestion, and is a trending enzyme for fall treatments. Passionfruit is packed with antioxidants and is perfect for aging skin, reduction of pore size, and breakout-prone skin. It has hydrating benefits, in addition to enzymatic action. The enzymes in phytic acid are gentle, skin-softening phytochemicals found in rice bran. The enzyme warms the skin and is not intended for use on sensitive skin conditions.    




The use of peptides as exfoliants are relatively new additions to the treatment arsenal. Peptides are not recommended to be used simultaneously with alpha hydroxy acids, as they do not work well in an acidic environment.


RNF-1 peptide’s intended purpose is not to cause flaking but to encourage healthy cell turnover rates.


Hexanoyl dipeptide-3 norleucine acetate (perfection peptide-3) reinitiates and accelerates the desquamation process.




Scrubs remove dead skin cells immediately, allowing for a deeper chemical peel penetration. Be sure to use a gentle tried and true scrub to not irritate or inflame skin before peel application. A few possible examples include the microdermabrasion scrubs using alumina, silica, or sea salt. Also consider jojoba beads, rice bran, and juglans regia (walnut) shell powder. 




Jessner’s plus TCA plus Retinol: The Jessner’s solution (salicylic acid plus resorcinol plus lactic acid in an ethanol base) is often used as a primer to optimize deeper peel penetration by disrupting the stratum corneum, allowing the TCA to penetrate deeper than when used alone.


  • pumpkin enzymes plus TCA and lactic acid blends
  • salicylic plus lactic acids
  • lactic, phytic, and mandelic acids
  • poly hydroxy acids plus retinoic acid




Typically, an alpha hydroxy acid and a beta hydroxy acid are not used together in the same treatment. For example, glycolic acid and salicylic combined can be irritating to the skin. However, as true with all skin care, it is often not the ingredient that is an issue but how a product is formulated. There are a few manufacturers that combine glycolic with salicylic or lactic with salicylic acids in the same formula to get the results of an alpha hydroxy acid with the keratolytic and anti-inflammatory benefits from the beta hydroxy. As noted earlier, it is not advised to combine a peptide exfoliant with an alpha hydroxy acid.


The crucial component to take note here is that each manufacturer has a cosmetic chemist or pharmacist that works with a research and development team to formulate safe and efficacious solutions, utilizing clinical trials and thorough product testing over a period of years before their peel solutions come to market. An individual skin care professional should never play chemist by mixing products on their own. Always follow manufacturer protocols.





  • Customization by applying the appropriate ingredients to address clients’ specific skin concerns.
  • Mixing or combining solutions in the hands of a skilled skin care professional offers the professional a way to step up the use of acids and move toward other advanced formulations. Acquiring manufacturer education and following protocols are mandatory.
  • Deeper penetration for enhanced benefits; for example, when trying to lift dermal melasma.
  • Maximum results – layering chemical peel solutions removes dead corneocytes, softening the appearance of wrinkles, while improving the skin’s tone and texture. Combining alpha hydroxy acids like lactic acid with TCA offers greater versatility, enhancing both acids’ uses and effects, while slowing down the combined acid effect, allowing for a more precise application and control of the treatment. Take note that that combining does not change the fundamental properties of the acid. Skin care professionals must use acids with great care and always work within their scope of practice.



  • Increased sensitivity
  • Potential for leaving the scope of practice with deeper penetration than allowed under one’s licensure
  • Increased risk of complications
  • Most peel solutions are too active for darker Fitzpatricks when layered
  • Close monitoring of the skin is required to judge tolerance




Have a thorough consultation. A thorough consultation and skin analysis are required to determine skin type, conditions, sensitivity levels, Fitzpatrick scale, assess goals, and determine if the client’s goals are realistic and achievable. Has the client used any exfoliants earlier that day or week? If so, which ones? Is the client under a physician’s care and using a prescription-strength retinoid, antibiotics, or any other products that would interfere with the treatment? Does the client have any current skin sensitivities? What are the client’s primary skin concerns?


Consider whether the client will be compliant with the aftercare instructions. Does the client have any allergies? For example, with an allergy to aspirin, avoid salicylic acid. Does the client have active cold sores or experience frequent herpetic breakouts? The client may need to pretreat with a prescription antiviral or with l-lysine supplements to prevent an outbreak following treatment.


Be conservative – it is best not to blend peels or layer different solutions until seeing how well the client tolerates each enzyme and acid individually before combining them.


Test patch all exfoliation types intended for use. Select exfoliants based on skin type, condition, and Fitzpatrick scale.




The five basic skin types are oily, dry, normal, mature, and combination. Skin type will vary at different times of an individual’s life; it is often affected by internal and external factors. Individuals are born with healthy skin, then experience oilier and combination skin in their teenage years and drier skin as they age.


Oily skin has overactive sebaceous activity; it appears shiny and feels greasy. Pores are larger than normal or dry skin. Beta hydroxy acids like salicylic acid are often used on oily and acne-prone skin.


Dry skin lacks lipids and natural moisturizing factors, sometimes referred to as alipidic. Pore size is small and sebaceous glands are underactive.


Combination skin contains a mixture of oilier skin, usually along the t-zone, with normal or dry skin in other areas.


Normal is the ideal skin type that is well balanced and not too oily or too dry.


Mature skin presents fine lines and wrinkles, is usually dry, and displays multiple age-related skin conditions.


Exfoliation allows the skin to breathe and enables any topically applied products to spread evenly and penetrate effectively. The barrier is improved, allowing it to fight infection and prevent moisture loss (transepidermal water loss). Exfoliation assists the skin in returning to homeostasis – the state of balance.




Skin conditions change throughout an individual’s life. Skin conditions include acne, photoaging, hyperpigmentation, eczema, rosacea, and couperose, amongst many others.


Hyperpigmentation, Photodamage, and Aging: Several exfoliation options work well for these conditions, such as retinoids for cell turnover and to balance skin tone and lactic acid for brightening and pigment suppression. Jessner’s solution combines 14% lactic acid, 14% salicylic acid, and resorcinol, but is not an option for Fitzpatrick IV to VI. Trichloroacetic acid (TCA) is a superficial to deep exfoliating agent (percentage and layer dependent) that can be applied in progressive layers. Low percentage phenol, TCA, and retinoic acid blends are excellent for pigment, advanced photodamage, and aging, with the additional benefit of being accessible to Fitzpatrick IV to VI.


Breakouts: Breakout-prone skin is often oily and inflamed. Salicylic acid is a standard go-to for its keratolytic and anti-inflammatory benefits. Pumpkin enzymes are excellent for purging the skin without post-treatment flaking.


Sensitized Skin: Sensitized skin is different from a sensitive skin condition. It is a temporary condition brought on by inappropriate use of products (too harsh) or by the environment (bitter, cold, wintry weather is just one example). First, find out what caused the client’s skin to become sensitized. Then, eliminate the offending ingredient or product and postpone treatment until the barrier function has been restored. When the skin’s barrier is intact, opt for mild microexfoliation with phytic acid combinations, which can simultaneously brighten and soothe without compromising the skin.


Sensitive Skin Conditions


Sensitive skin conditions must be diagnosed by a physician. Mild exfoliation can be beneficial for sensitive skin, but advanced exfoliation techniques are not recommended for this condition. Blend acids like lactic and malic to provide much-needed hydration, but do not combine exfoliation methods hoping for deeper peel penetration. The three most common types of sensitive skin are rosacea, psoriasis, and eczema.


Rosacea: Over 415 million people suffer from this vascular disorder. A rosacea client’s skin appears red, irritated, and may have dilated capillaries, a rough texture, papules, and pustule. A mild TCA peel (10% or under) combined with lactic acid can remove damaged skin cells, replacing them with healthy new ones. Keep treatment plans simple. Do not incorporate advanced treatments. Concentrate on calming inflammation, reducing erythema, and restoring skin barrier function.


Psoriasis: Psoriasis is a condition that involves an extremely rapid cell turnover cycle (just three to five days on average). Cells pile up on the surface because they cannot desquamate properly. The goal is to remove existing plaques while softening the surrounding skin and restoring the skin barrier. Lactic and malic acids can hydrate while exfoliating.


Eczema: Focus on hydration, barrier repair, and skin conditioning prior to exfoliation. Do not treat red and inflamed skin. Start with gentle enzymes followed by subsequent treatments, incorporating chemical peels using milder acids like poly hydroxy acids, phytic and malic acids, or blends that include those ingredients.



Consider the Fitzpatrick scale, as it can influence ingredient choice. Many chemical peels are deemed too strong for darker skin tones (Fitzpatrick IV to VI).


Fitzpatrick I clients have a pale, porcelain, or ivory complexion; they usually have more resilient skin and are open to all exfoliants.


Fitzpatrick II skin types have golden or beige tones; they are not too reactive and tolerate alpha hydroxy acids, beta hydroxy acids, poly hydroxy acids, Jessner’s, and TCAs well.


Fitzpatrick III skin types have olive skin tones; they are tolerant of most exfoliant choices and blends.


Fitzpatrick IV has a medium brown skin tone with olive-caramel tones and dark hair and eyes. This Fitzpatrick is more sensitive than its predecessors. Use caution with higher percentage alpha hydroxy acids, blended peels, and TCA over 10% – Jessner’s peels are usually not recommended.


Fitzpatrick V is a dark skin tone ranging from radiant bronze to vibrant brown complexion. Inflammation is easily triggered in this skin type, which can lead to post-inflammatory hyperpigmentation. Follow the manufacturer’s suggestions for skin color, as many chemicals peels may be too aggressive for skin of color.


Fitzpatrick VI is the deepest skin tone. A high percentage of acids and Jessner solutions are usually considered contraindicated. Darker skin tones occasionally tolerate TCAs under 10%. Always patch test.




Is the client pregnant or lactating? Do not treat with chemicals, as they have not been tested for safety. Use only products that are approved for pregnancy and lactation. Advise the client that as soon as it is safe to proceed with chemoexfoliation, you will do so. Continue with mild monthly facials.


Does the client have any current areas of rashes, irritation, or inflammation? Decline treatment until the condition has subsided.




Select the exfoliation products for the treatment. Always check to be sure that the client has tolerated individual treatments well before combining them. Explain the process to the client, including what ingredients will be applied and why and what to expect during and after the treatment. Confirm that the client has no allergies or sensitivities to the products that will be used. Reconfirm agreement for the procedure, then begin.


Cleanse, degrease, and ask for sensitivity level. Choose degreasing cleanser followed by the manufacturer’s suggested peel preparation degreasing solution. After degreasing the treatment area, ask the client what their level of comfort is from zero to 10, with zero being completely comfortable and 10 being extreme discomfort. It is important to know what tolerance level the client is at before, during, and at the conclusion of the procedure. Most professionals use visual indicators (frosting or blanching) or tolerance levels as the endpoint for their procedures. Each professional will have their comfort level as well. I do not like to have a client feel higher than a six or seven at any point in the treatment. Remember that the tolerance level may spike upon application then subside after a few seconds. If using a manual or electric fan during the procedure (for client comfort), remove it while gaging tolerance or sensitivity levels to get an accurate reading.


Apply the first layer and neutralize or remove. Apply a light and even layer of salicylic acid, enzyme, or scrub to the treatment area. Observe the client’s skin for flushing, frosting, or other reaction. Ask for comfort level (zero to 10). Neutralize if required or remove the product if using an enzyme or scrub.


Apply the second layer; neutralize or remove if required. Apply a light and even layer of the selected exfoliant to the treatment area. Follow the manufacturer’s direction as to time in contact with the skin and watch for erythema, edema, frosting, or blanching. Ask for comfort level (zero to 10). Many manufacturers will not recommend neutralizing a TCA or Jessner’s solution, as they self-neutralize. The important issue at hand is to always follow the manufacturer’s protocol. If the protocol says to neutralize or remove, do so before proceeding with the next layer to avoid the risk of complications.


Apply the third layer; neutralize or remove if required. If the manufacturer’s protocol recommends, apply a second layer of peel solution lightly and evenly to the treatment area. Follow the manufacturer’s direction as to time in contact with the skin and watch for erythema, edema, frosting, or blanching. Ask for comfort level (zero to 10). Most manufacturer’s protocols will stop after two layers of peel solution. Neutralize the solution if the manufacturer’s protocol directs you to do so.


Apply a moisturizer and sunscreen (when suggested by the manufacturer). Some manufacturers prefer that the professional apply a calming moisturizer and broad-spectrum sunscreen to complete the treatment, while others prefer to let the skin breathe without these products. Always follow manufacturer directions.


Post-peel instructions. Send the client home with a post-treatment kit that includes a gentle aloe-based cleanser, a calming, hydrocortisone-free moisturizer, and broad-spectrum sunscreen. Call the client within 48 hours to see if they have any questions or concerns and be sure that the client has the spa’s contact information, as well.


For 48 to 72 hours post-treatment, have the client avoid ultraviolet exposure, strenuous activities, heat, scrubs, and retinol. Discourage any waxing services in the treated area for at least one week.


Have the client avoid all regular skin care products for the week following treatment. Many cleansers, creams, and serums are too irritating during the flaking process. The client may resume their normal skin care regimen after all exfoliation has subsided.


The ever-changing industry offers the professional multiple therapeutic options to achieve phenomenal results to address each client’s skin care concerns. Take the time to research which treatments work best for the business and stay within the scope of practice, while being safe and efficacious.




Brenda Linday 2014



Brenda Linday, L.E., L.E.I., C.A.C., Linday Aesthetic Consulting, is a licensed aesthetician, licensed aesthetic instructor, and certified aesthetic consultant with over 15 years of experience in the medical aesthetic industry. Linday serves as a consultant for medical and aesthetic companies desiring to build strong sales and education teams. She develops clinical and sales education content and trains sales and educational teams, clinicians, physicians, and distributors around the world. Linday is also a featured author in many industry publications. Her passion is sharing her wealth of knowledge with other like-minded professionals who believe that education is the key to building lasting relationships with clients, making each clinician more successful by increasing client satisfaction. This email address is being protected from spambots. You need JavaScript enabled to view it. or @lindayconsult

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