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Exfoliation – A Guide To AHAs, BHAs, And Enzymes For Youthful, Healthy Skin

Ida is a certified aesthetician (graduate of Marvel School of Beauty), offering home-based services since 1994. Ida provides various holistic services; she graduated from Zanqara’s Holistica Skin Care’s Dermatician course in 1994, which required her to understand homeopathic remedies.

Executive Contributor Ida Fanelli

Cell production and exfoliation slow down as skin ages, leading to dryness and a dull complexion. The decline of enzymes that recycle dead skin cells compromises the skin’s barrier. Regular exfoliation helps prevent clogged pores, reduces breakouts, and indirectly stimulates collagen production and skin elasticity, Improving skin care product absorption is essential for maintaining a youthful, healthy appearance. I share the strengths and weaknesses of various exfoliators, including alpha-hydroxy acids (AHAs), beta-hydroxy acids (BHAs), polyhydroxy acids (PHAs), and enzyme-based exfoliators, providing insights into their chemical compositions, benefits, and potential contraindications.

Beautiful girl touching her skin


Alpha-hydroxy acids (AHAs) are organic fruit acids popular in skincare for their exfoliating properties. Common AHAs include:

  • Glycolic acid from sugar cane.

  • Citric acid from citrus fruits.

  • Malic acid from apples.

  • Lactic acid from milk.

  • Tartaric acid from grapes.


Glycolic acid

Chemical composition and industrial origin

Glycolic acid (C2H4O3) is water soluble and has the smallest molecule of the AHAs, allowing for deep penetration. Manufacturers derive it from sugar cane, plants, and petrochemical derivates such as monochloroacetic acid and formaldehyde. In China and India, chemical plants ferment glucose using a technique that often involves formaldehyde. However, the petrochemical methods usually leave trace amounts of formaldehyde in the final product. The toxic chemical formaldehyde preserves dead tissues. A sustainable VOC-free technique exists that ferments plant-based sources to produce glycolic acid. Consumers should perform due diligence by checking ingredients or manufacturer information. Look for bio-based or formaldehyde-free labels. Seek third-party verifications, such as the USDA Certified Bio-Based Product label, to confirm petrochemical contaminants’ biobased content and absence.


Industrial uses and environmental impact

Commercial companies use glycolic acid as an industrial cleaning chemical. Textile manufacturers use it to weaken the binding properties of leather to enable tanning. Glycolic acid is a deadly by-product of ingesting antifreeze.​ Another commercial use for glycolic acid is biodegradable polymers for producing medical sutures, surgical devices, and drug dispensers. These industrial applications should make us suspicious of its suitability for skincare products.


Skin penetration and effects

Glycolic acid’s small molecular size makes it appealing for deep penetration in cosmetic skincare. Unfortunately, some of it penetrates the circulatory system.


Risk of permanent skin damage

If the glycolic peel is too strong or left on for too long, it can lead to permanent skin damage, such as hyperpigmentation and scarring. People with darker copper tones complexions have a higher risk of post-inflammatory hyperpigmentation. ​


Scarring from using strong peels

There’s a low risk of scarring from high concentrations, particularly for those prone to keloids or abnormal skin scarring. Before undergoing the peel, it is essential to inform your dermatologist of any history of such conditions.


Skin thinning

Prolonged use can thin the skin’s outer layer, increasing sensitivity and potential damage. Surface dead epithelial and live dermis skin cells are loosened and shed.


Infection and allergic reactions

Infections are rare if the client doesn’t follow the peel’s aftercare instructions correctly.


Sun sensitivity hyperpigmentation and other risks

AHAs, including glycolic acid, increase the risk of sunburn and skin cancer by making skin more sensitive to UV rays. Inaccurate strengths and repetitions without sun protection can cause hyperpigmentation and sun damage. The pigment-producing cells deep underneath are more vulnerable to further sun damage by up to 50%. Darker skin is more prone to dark spots and changes in skin tone. The skin’s sensitivity to UV rays increases the risk of sunburn and skin cancer. Applying high SPF sunscreen for several weeks is crucial to protect the newly exposed skin layers from sun damage.​


Skin irritation

Due to its deep penetration, glycolic acid can be exceptionally irritating, mainly if used excessively or if the products are too strong. Skin irritation, such as redness, itching, swelling, or burning, indicates that the skin is not tolerating the product well. If irritation occurs, it’s crucial to discontinue use and rinse the skin with clean water.


Benefits are short-term

AHA and acids produce a temporary improvement in the condition of the skin. Fine lines and mild puffiness that tighten the skin do not last. Long-term results make the skin appear to lose its elasticity. The thinning of the outermost layer of skin against the elements increases the possibility of sunburn and sensitivity for up to a week after application. It makes skin appear shiny by removing the protection your skin requires against the elements. Prolonged sun exposure can cause crepey skin and loss of elasticity due to the breakdown of elastin fibres and collagen. Repeated exposure causes the fibres to lose their retraction ability. The connective tissue protein collagen also weakens. The fat in the lowest layer of the skin becomes uneven and flattens. Surface capillaries become more fragile, causing bruising. This layer also becomes drier and more transparent as skin loses pigment, and the cells in this area begin shrinking. The Sun’s UV rays also damage the skin’s lymphatic system, affecting the immune system and its ability to clean out impurities.


Precautions for glycolic acid use

  • Infants and Children: Not recommended.

  • Pregnant and breastfeeding clients. It would be best if you avoided it.

  • Irritated Skin: Avoid recently microneedled, broken, sore, or sunburned skin and conditions like eczema.

  • Sensitive Skin: Not recommended for individuals with rosacea, severe erythema or sensitive skin.

  • Compromised Immune Systems: Cancer survivors and people with weak immune systems should avoid topical application of chemical peel treatments and products.

  • Patch Test: Test a small area to determine a client’s tolerance

  • Gradual Introduction: Start with lower concentrations and increase gradually.

  • Eye Contact: Rinse eyes immediately if it gets into the eyes.

  • Sun Protection: Use sunscreen daily when using AHAs/BHAs.

  • Dryness and Peeling: Following the treatment, the skin often becomes dry and peels, a normal part of the healing process. Moisturizers and gentle skincare are recommended during this period to aid recovery​.

  • Retinol products: Avoid AHA peels when using

  • Accutane or other medications: Avoid altogether.


The risks you need to know of using strong glycolic acid in skincare

Practitioners inform us that glycolic acid molecules are primarily active on the skin’s surface and are not absorbed in significant amounts into the bloodstream to cause systemic effects and that proper neutralization further ensures that the acid does not continue to cause damage beyond the intended superficial layers of the skin.


The Kidney Foundation is concerned about the amount of Glycolic acid that could enter the bloodstream via the skin when used in high concentrations of chemical peels.


Hair straightening treatments

Several clients in Israel have received hair straightening treatments using glycolic acid derivatives. Some required temporary dialysis, and others showed oxalate formation from kidney biopsies. Abnormal blood levels, which indicated kidney issues, were analyzed, but glycolic acid levels were undetected.


Glycolic acid peels

Another woman who had several concentrated glycolic acid peels required medical attention after each session. Her blood levels demonstrated impaired kidney function.


Formaldehyde inhalation or absorption

Significant heat can enhance skin absorption of glycolic acid derivatives into the circulatory system. For example, some cosmetic glycolic acid derivative treatments emit formaldehyde when exposed to high heat. Formaldehyde is a known toxin that can lead to various health problems, including kidney damage when it is inhaled or absorbed through the skin​​.

There are rare occurrences of improper use or excessive glycolic acid concentrations. It’s essential to follow guidelines for glycolic peel applications and consult with medical professionals, especially individuals with pre-existing conditions or concerns about systemic toxicity.


The Environmental Working Group (EWG) gives glycolic acid a 3-6 fair rating depending on usage. The higher the rating, the worse the score.


Health Canada restricts its use in Canadian products.

Direct consumption of glycolic acid or products that convert to glycolic acid, like antifreeze, can cause acute renal failure, metabolic acidosis and death.


Chemical composition and synthesis of lactic acid

Lactic acid (C 3 H 6 O 3) is a less irritating AHA that doesn’t compromise the lipid barrier with overuse. It’s naturally in sour milk. Lactic acid in skincare is typically synthetic or plant-derived.

  • Plant-derived sources: Lactobacillus bacteria ferment plant-based materials, such as corn starch or beet sugar, to produce lactic acid. It meets ethical and environmental considerations​.

  • Synthetic production: Lactobacillus cultures ferment sugars such as glucose or sucrose to produce lactic acid. Calcium carbonate (chalk) is added to maintain pH levels and indirectly ferments in this mixture.


Benefits of lactic acid

It encourages ceramide production, cell renewal, firmness, hydration, and smoothness, and brightens and reduces fine lines and wrinkles, making it a gentler option to glycolic acid. However, it may pose risks if used excessively. 


Our body requires lactic acid

  • As a fuel source for mitochondria in all cells

  • Enables glucose production

  • Signals where you need healing


Side effects of lactic acid

  • Skin Irritation: When introducing Lactic Acid into a skincare routine or using it at higher concentrations, some people might experience temporary skin irritation.

  • Dryness: Excessive use can cause dryness

  • Photosensitivity: Lactic acid weakens the skin’s protective layer and makes it more sensitive to the sun. Protect with SPF.

Who can use

  • All skin types can accept lactic acid; however, we recommend it for sensitive, dry, and mature skin.

  • Pregnant and breastfeeding women can generally use products containing Lactic Acid without concern. The topical application of lactic acid in skincare products does not cause specific worries about entering the bloodstream in significant amounts.


The environmental working group

Rates Lactic Acid as a 2-5 and states the rating would be higher (worse) in products that cause respiratory concerns, such as inhalable products. They see it as a safer ingredient in solids and liquids.


Beta Hydroxy Acids(BHAs)

BHA, like salicylic acid, is oil-soluble and treats oily and acne-prone skin. Salicylic acid, derived from willow bark, unclogs pores and reduces blackheads and whiteheads. Another more potent BHA, trethocanic acid, is derived from pine bark and is less common.

The environmental working group: Rates Salicylic acid 5-8 (unacceptable) and states that the rating would be higher (worse) if it is in products that cause respiratory concerns, such as inhalable products. They see it as a safer ingredient in solids and liquids.

Polyhydroxy Acids(PHAs)

PHAs, such as lactobionic acid, are gentle and non-irritating, making them suitable for sensitive skin.


The environmental working group approves lactobionic acid and rates it as a 1.

The enzyme-based exfoliators

Enzymes are naturally complex proteins that increase the rate of protein-based reactions without undergoing the reactions themselves. They break down skin proteins into peptides and amino acids, which the skin absorbs to generate new cell growth. Enzyme exfoliators, like those derived from papaya, pineapple, pomegranate, cherries, and pumpkin, offer a gentler alternative to chemical exfoliators without the risk of sunburn peeling. Proteolytic enzymes are also used in digestive enzymes to help the body assimilate protein from food.


My experience with enzyme peels

I am a Holistic Aesthetician. I’ve performed Zanqara’s enzyme peel and Zanqara Profile peel since 1994. The enzyme peel breaks up dead skin cells and removes one layer of live skin cells. It deeply exfoliates the skin and refines pores without overly harsh and stripping. I’ve used it on sensitive and oily skin types. The Profile Peel is less aggressive but has skin-tightening qualities. I can add various extracts to personalize to all skin types. Both have less downtime from sun exposure. Enzymes work optimally at body temperature.



Bromelain is the main reason pineapple is known to have skin-beautifying and brightening properties. It has concentrated bromelain in the pineapple core, stem, and husk.

It’s an anti-inflammatory agent known for its antioxidant and antibacterial properties.


The environmental working group sees it as a 1-2. Relatively safe.

Glyoxysomal catalase

Pumpkin contains this enzyme, which has a smaller molecular structure than most fruit enzymes, making it easier to penetrate the skin surface. It destroys free radicals, which helps prevent premature aging. 



Unripe papaya contains it.

Papain is known for removing damaged keratin from the skin, brightening and evening the complexion. Papaya’s enzyme papain helps reduce inflammation, age spots and smooth skin texture.


The environmental working group sees it as a 1-2. Relatively safe.

Fermented Pomegranate Enzymes multi-tasks as a potent skin brightener and powerful

antioxidant with pigment-inhibiting qualities



Actinidin enzyme is in kiwi, mango, papaya, pineapple, and banana.

This enzyme exfoliates dead surface skin cells, moisturizes the skin and keeps it supple.


The environmental working group approves it and rates it as a 1.


Ficin is most commonly found in figs and works well for removing scars and pigmentation.

It also makes your skin visibly softer and smoother.



Potatoes have catecholase, which exfoliates mildly.


Comparison of enzyme and acid peels

Enzyme and acid peels are effective exfoliants that enhance skin brightness and smoothness, reduce age spots, and better prepare the skin to absorb moisturizer nutrients. Here’s a comparison of their effects and properties:


Exfoliation and cell turnover

  • Enzymes: Break down and dissolve the dead protein in the uppermost layer of the skin, facilitating skin renewal.

  • Acids: Dissolves the glue that attaches dead skin cells and penetrates the pores, promoting cell turnover.


Suitability for skin types

  • Enzymes: Suitable for oily, acne-prone, sensitive, scarred and combination skin. Their antibacterial properties help unclog pores and prevent blackhead formation.

  • Acids (AHAs/BHAs): It is effective for oily, acne-prone, scarred and combination skin. Still, it can be too intense for sensitive skin or those with darker skin tones, often requiring a period of acclimatization.


Effect on skin

  • Enzymes: Slightly dilate pore openings, enhancing skincare absorption.

  • Acids: Work best at low pH to denature the protein between skin cells, loosening their connection.


Additional benefits

  • Enzymes have anti-inflammatory properties that soothe the skin, which are beneficial for conditions like redness, inflammation, and possibly rosacea. Research indicates enzymes like papain and bromelain have potential anticancer properties due to their ability to break down cell walls.

  • Acids require careful pH management to avoid disrupting the skin’s acid mantle barrier. For optimal exfoliation, gradually adjust glycolic acid levels, starting from lower concentrations (2-4%) and increasing over time.


Speed and results

  • Enzymes: Act quickly, making them ideal for consumers seeking instant, visible results. They also offer antioxidant benefits and can be formulated to boost collagen production.

  • Acids: Work effectively at low pH but can cause irritation or inflammation in sensitive and darker skin tones if not used properly.


Safety and recommendations

  • Enzymes are derived from natural sources like fruits and generally do not contain aggressive ingredients. However, consulting with a physician before use is recommended.

  • Acids: Gradually adjusting concentrations should be taken to avoid skin irritation.


Overall benefits

Both enzymes and acids allow deeper penetration of serums and moisturizers to penetrate the skin deeper, enhancing their effectiveness.

Both have anti-inflammatory properties that help soothe the skin and reduce redness or inflammation.


Peeling effect

  • Enzyme peeling occurs invisibly.

  • Acid Peels sunburn peeling occurs a day or so after application.


Avoid the use of the following for both Enzymes and acids 

Avoid sun tanning, tanning beds, henna brow tinting, laser or Intense Pulse Light and waxing hair removal sessions. 


Contraindication of enzymes

  • Retinol products: Avoid AHA peels when using

  • Accutane or other medications: Avoid altogether.

  • Pregnant and breastfeeding clients can use enzyme exfoliators to get glowing skin.

  • Allergic reaction: Green Raw papaya contains the enzyme papain. They drain the milky white latex from the flesh. Latex allergy or other ingredients in enzyme-based products are one of its few contraindications or side effects.

  • Avoid on microneedles, broken, irritated.



In conclusion, while AHAs and BHAs offer significant exfoliation and skin renewal benefits, they pose considerable risks, especially for sensitive skin or specific health conditions. Enzyme-based exfoliators provide a gentler alternative, effectively promoting cell turnover with fewer side effects. Both types of exfoliators can enhance the effectiveness of skincare routines. By understanding the benefits and risks of these exfoliators, individuals can make informed choices to achieve and maintain healthier, more radiant skin.


Skincare approach

Transitioning clients to my skincare line, Zanqara, which uses plant-based enzymes instead of AHAs and BHAs, improves skincare experiences without the dangerous side effects of AHA and BHA.

To set up a Zanqara account and make purchases, visit here and email Use Promo Code IDA10 to get 10 % off your first purchase.


The Food and Drug Administration requires me to state that cosmetic products do not diagnose, treat, cure, or prevent disease. 

Follow me on Facebook, Instagram, LinkedIn, and visit my website for more info!


Ida Fanelli, Aesthetician, Reflexologist, IPL Technician

Ida is a certified aesthetician (graduate of Marvel School of Beauty), offering home-based services since 1994. Ida provides various holistic services; she graduated from Zanqara’s Holistica Skin Care’s Dermatician course in 1994, which required her to understand homeopathic remedies. Ida has been a certified reflexologist since 1993 (graduate of D’Arcy Lane Institute). She has also been practicing Healing Energy since 1998 and has added the Ion Cleanse Foot Detox to her therapies. In 2012, Ida became a certified Sharplight Laser (IPL) Technician. She enjoys learning new techniques which can benefit her clients. In 2019, she received certification from the Center for Pain and Stress Research (CPSR.) She can now speed up the healing of scars and help with pain caused by surgical scars to her list of specialties.

She enjoys continuing her education in the complementary health field. Many can testify that Ida is committed to ensuring her clients access adequate and affordable quality service and treatment.

Beyond her many years of experience as a holistic practitioner, Ida draws on her 12 years of experience as a hospital laboratory technologist in Microbiology and Biochemistry.


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