Glycolic Acid Side Effects, Risks, and Safety

Complete guide to glycolic acid side effects including sun sensitivity, chemical burns, and who should avoid it. Evidence-based safety information.

Updated Feb 22, 2026

14 min read

This article covers topics that carry real skin-damage risk. Do not attempt professional-strength treatments at home without consulting a board-certified dermatologist.

Glycolic acid is generally safe for most adults when used correctly, but it carries real risks that deserve honest discussion. The most common side effects - stinging, redness, and dryness - are usually mild and temporary. More serious risks include chemical burns from high-concentration products, increased sun sensitivity leading to UV damage, and worsened skin conditions when used by people with certain contraindications. Understanding these risks helps you use glycolic acid safely and recognize when to stop [1].

Most Common Side Effect

Mild Stinging

Brief tingling or stinging for 1–5 minutes after application is the most frequently reported side effect.

UV Sensitivity Increase

~20% Lower MED

AHA use reduces the minimum UV dose needed to cause redness by approximately 20% (Kornhauser 2009). Daily sunscreen is mandatory.

Safe OTC Range

2% – 15%

Over-the-counter products should not exceed 15%. Higher concentrations require professional supervision.

Pros

Effective exfoliation improves texture, tone, and clarity
Clinically proven to help acne, hyperpigmentation, and photoaging
Stimulates collagen mRNA and hyaluronic acid production
Accessible OTC concentrations (2%–15%) are well-tolerated by most adults
Side effects are usually mild and resolve as tolerance builds

Cons

Stinging, redness, and dryness during the first 1–4 weeks
Increased sun sensitivity (persists at least a week after last use)
Risk of chemical burns at concentrations above 20%
Can worsen rosacea, eczema, and compromised skin barriers
Potential post-inflammatory hyperpigmentation in darker skin tones if irritation occurs
Drug interactions with isotretinoin, retinoids, and photosensitizing medications

Common Side Effects

The following side effects are frequently reported by glycolic acid users, particularly during the first 1–4 weeks of use. Most are signs of the acid working on the skin and resolve as tolerance builds.

Stinging and Tingling

The most common immediate reaction. Glycolic acid's low pH triggers a mild sensory response when it contacts the skin. This typically lasts 1–5 minutes after application and should not be painful. A tingling sensation is normal; sharp, burning pain is not.

Redness (Erythema)

Mild redness after application is common, especially in the first two weeks. It should resolve within 30 minutes to a few hours. Redness that persists beyond several hours or worsens with each application suggests the product is too strong or being used too frequently.

Dryness and Flaking

Glycolic acid accelerates the shedding of dead skin cells. During the adjustment period, this manifests as visible dryness and mild flaking, particularly around the nose, chin, and jawline. A good moisturizer applied after the glycolic acid product should manage this effectively.

Temporary Tightness

Some users report a sensation of skin tightness after application. This is related to the exfoliation of the surface layer and temporary disruption of the lipid barrier. It should resolve within an hour, especially after applying moisturizer.

Purging

In the first 2–6 weeks, glycolic acid can trigger what is commonly called a "purge" - an increase in small breakouts as accelerated cell turnover pushes pre-existing microcomedones (blocked pores below the skin surface) to the surface faster than they would appear naturally. Purging typically resolves within 4–8 weeks. If new breakouts appear in areas where you do not normally break out, or if they persist beyond 8 weeks, the product may be causing genuine irritation rather than purging [1].

When Side Effects Are Normal vs. Concerning

Distinguishing between expected adjustment and a genuine adverse reaction is important for safe use.

Normal (Continue Use, Monitor)

Mild tingling lasting under 5 minutes
Slight redness that fades within 1–2 hours
Minor dryness or flaking in the first 2 weeks
Small breakouts in your usual breakout areas during weeks 1–6

Concerning (Reduce Frequency or Concentration)

Tingling that intensifies rather than fading over 2 weeks
Redness lasting more than 4 hours after application
Persistent dryness or flaking despite regular moisturizer use
Skin that feels "raw," sensitive to water, or painful to touch

Stop Immediately and Consult a Dermatologist

Burning pain (not just tingling) during or after application
Blistering or visible skin damage
Swelling, especially around the eyes or lips
Rash, hives, or signs of allergic reaction
Skin that appears darker in treated areas (possible post-inflammatory hyperpigmentation)

Sun Sensitivity

Increased photosensitivity is the most clinically significant side effect of glycolic acid. It is not a theoretical concern - it has been demonstrated in controlled studies.

What the Research Shows

Kornhauser et al. (2009) investigated the effects of topical glycolic acid on UV-induced skin damage. The study found that glycolic acid application increased UV-induced erythema (sunburn), DNA damage, and sunburn cell formation in human skin [2]. This photosensitizing effect occurs because glycolic acid thins the stratum corneum - the outermost layer of skin that provides a degree of natural UV protection. By accelerating the removal of these protective dead cells, glycolic acid reduces the skin's baseline UV defense.

The increased sensitivity is not limited to the day of application. Research suggests that the photosensitizing effect persists for at least a week after the last use of an AHA product [3].

What This Means for You

Sunscreen is mandatory. Use a broad-spectrum SPF 30 or higher every morning, regardless of weather or whether you plan to spend time outdoors. UV radiation penetrates clouds and glass.
Reapply sunscreen every 2 hours during extended outdoor exposure.
Consider additional UV protection (hat, sunglasses, seeking shade) if you are using glycolic acid at concentrations above 10%.
Do not use glycolic acid as a "tan prep." Some people mistakenly believe that exfoliation before sun exposure will produce a better tan. This is dangerous - you are removing UV-protective skin cells and increasing your risk of sunburn, DNA damage, and long-term photoaging.

Concentration and pH Risks

The risk of adverse effects from glycolic acid is directly related to two factors: concentration and pH.

Concentration

Higher concentrations mean more acid molecules contacting the skin, which increases both efficacy and risk:

2%–10%: Standard over-the-counter range. Generally well-tolerated with proper use. Risk of serious adverse effects is low.
10%–20%: Higher-end OTC and at-home peel range. Increased risk of irritation, especially without established tolerance. Should not be used daily.
20%–35%: Light professional peels. Should be performed by a licensed aesthetician. Risk of chemical burns if contact time is not carefully controlled.
50%–70%: Medium-depth peels. Must be performed by a dermatologist. Significant risk of scarring, burns, and post-inflammatory hyperpigmentation if performed incorrectly.

pH

pH determines how much of the glycolic acid exists in its free, active form. At a pH below glycolic acid's pKa of 3.83, a higher percentage of the acid is protonated (un-ionized) and able to penetrate the skin. The lower the pH, the more potent the product - and the higher the irritation risk. Our pH science guide explains this relationship in depth [3].

pH 3.0–3.5: High potency. Maximum exfoliating effect. Higher irritation risk.
pH 3.5–4.0: Moderate potency. Good balance of efficacy and tolerability for most users.
pH 4.0–4.5: Lower potency. Reduced irritation but also reduced efficacy. Often used in "sensitive skin" formulations.
pH above 4.5: Minimal active free acid. Glycolic acid at this pH provides limited exfoliation.

The Danger Zone

The combination of high concentration AND low pH creates the greatest risk. A 30% glycolic acid product at pH 2.5 is far more aggressive than a 30% product at pH 3.8. Professional peels are carefully calibrated to balance these factors, which is one reason they should not be replicated at home.

Who Should Avoid Glycolic Acid

While glycolic acid is safe for most adults, certain conditions and situations make it inadvisable.

Rosacea

Glycolic acid can trigger rosacea flares. The low pH and exfoliating action can worsen the redness, burning, and inflammation characteristic of rosacea. People with rosacea should consult their dermatologist before using any AHA. Some dermatologists may recommend a very low concentration (2%–5%) at a higher pH, but many will advise against glycolic acid entirely in favor of gentler alternatives like polyhydroxy acids (PHAs).

Active Eczema or Dermatitis

Applying acid to skin that is already inflamed, cracked, or barrier-compromised will cause pain and may worsen the condition. Wait until the eczema or dermatitis is fully resolved and the skin barrier has recovered before introducing glycolic acid.

Open Wounds, Cuts, or Sunburned Skin

Never apply glycolic acid to broken, cut, or sunburned skin. The acid will penetrate damaged tissue far more aggressively than intact skin, causing disproportionate irritation and potentially scarring.

Very Sensitive Skin

If you react to most active skincare ingredients, glycolic acid - as the most potent AHA - may not be right for you. Consider mandelic acid (larger molecule, slower penetration, less irritation), lactic acid (slightly gentler than glycolic), or polyhydroxy acids (PHAs like gluconolactone) as alternatives - see our other AHA comparison for details.

Post-Procedure Skin

After microneedling, laser treatments, dermabrasion, or medium-to-deep chemical peels, the skin barrier is significantly compromised. Wait until your treating physician clears you before resuming any acid products. This typically means 1–4 weeks depending on the procedure.

Pregnancy and Breastfeeding

The safety of glycolic acid during pregnancy and breastfeeding is a topic where available data is limited and expert opinion varies.

What We Know

Glycolic acid is a small molecule that can penetrate the epidermis, but systemic absorption from typical over-the-counter concentrations (2%–10%) applied to the face is considered minimal. No human studies have specifically evaluated the effects of topical glycolic acid on fetal development or breast milk composition.

Current Expert Guidance

Most dermatologists consider low-concentration topical glycolic acid (under 10%) to be likely safe during pregnancy, as systemic absorption is negligible. However, high-concentration peels (20%+) are generally avoided during pregnancy as a precaution, because deeper penetration could theoretically increase systemic absorption [4].

The American College of Obstetricians and Gynecologists does not specifically address glycolic acid in its guidelines on cosmetic procedures during pregnancy, but does recommend discussing all skincare products with your OB-GYN or midwife.

Safer Alternatives During Pregnancy

If you choose to avoid glycolic acid during pregnancy, alternatives generally considered safe by dermatologists include:

Azelaic acid (well-studied in pregnancy for acne and hyperpigmentation)
Gentle physical exfoliation (soft cloth, gentle scrubs)
Hyaluronic acid (hydration, not exfoliation, and does not carry AHA risks)
Lactic acid at very low concentrations (considered low-risk by most practitioners)

Drug Interactions

Glycolic acid can interact with certain medications that affect the skin or increase photosensitivity.

Isotretinoin (Accutane)

Isotretinoin dramatically thins the skin and impairs barrier function. Using glycolic acid during or shortly after isotretinoin treatment creates a high risk of severe irritation, chemical burns, and scarring. Most dermatologists recommend waiting at least 6 months - some recommend 12 months - after completing isotretinoin before introducing glycolic acid [1].

Topical Retinoids (Tretinoin, Adapalene, Tazarotene)

Topical retinoids and glycolic acid both increase cell turnover and can compromise the skin barrier. Using them simultaneously (in the same routine step) significantly increases the risk of irritation. They can coexist in a routine if used on alternate evenings, but this should be approached gradually. For a detailed comparison, see our glycolic vs retinol guide.

Photosensitizing Medications

Certain oral medications increase skin sensitivity to UV radiation. Combining these with glycolic acid (which also increases photosensitivity) compounds the risk. Common photosensitizing medications include:

Doxycycline and other tetracycline antibiotics
Certain NSAIDs (naproxen, piroxicam)
Thiazide diuretics (hydrochlorothiazide)
Fluoroquinolone antibiotics (ciprofloxacin)
Some antifungal medications (voriconazole)

If you are taking any photosensitizing medication, inform your dermatologist before starting glycolic acid. Extra sunscreen vigilance is essential, and lower glycolic acid concentrations are advisable. Check our interaction checker for a full list of medications and ingredients that interact with glycolic acid.

Topical Corticosteroids

Long-term use of topical corticosteroids thins the skin. Introducing glycolic acid on steroid-thinned skin may cause disproportionate penetration and irritation. Discuss timing with your dermatologist.

How to Minimize Side Effects

If you choose to use glycolic acid, these practices will reduce the likelihood and severity of side effects.

Start Low and Go Slow

The single most effective strategy. Begin with 5%–7% concentration, 2–3 times per week, and increase gradually over weeks. This gives your skin time to adapt and your barrier time to adjust. For a detailed beginner protocol, see our how to use glycolic acid guide.

Use Buffered Products

Some glycolic acid products are "buffered" - partially neutralized to a higher pH, reducing the percentage of free acid and the intensity of exfoliation. Buffered products are a good choice for sensitive skin or first-time users, even though they deliver less active acid per application.

Moisturize Consistently

Apply a ceramide- or hyaluronic acid-containing moisturizer after every glycolic acid application. This supports barrier repair and reduces transepidermal water loss (TEWL), which glycolic acid temporarily increases [3].

Never Skip Sunscreen

Broad-spectrum SPF 30+ every morning, every day, while using glycolic acid. This is the most important risk-mitigation step.

Do Not Combine Too Many Actives

Resist the temptation to use glycolic acid alongside retinoids, salicylic acid, and high-concentration vitamin C all at once. Each of these ingredients is individually effective; stacking them together does not produce additive benefits but does produce additive irritation.

Listen to Your Skin

If your skin is red, tight, or stinging hours after application - or if it is getting worse rather than better over 2–3 weeks - your current product is too strong or too frequent for your skin. Reducing intensity is not a failure; it is intelligent self-care.

When to See a Dermatologist

Seek professional evaluation if you experience:

Chemical burn symptoms: intense pain, white or grey skin patches, blistering, skin that looks "raw" or weeping
Allergic reaction: hives, widespread rash, swelling beyond the application area
Persistent PIH: treated areas becoming darker rather than lighter after 4+ weeks of use
No improvement after 12 weeks of correct, consistent use - a dermatologist can evaluate whether glycolic acid is the right approach for your specific concerns
Uncertainty about interactions with other medications or skin conditions you are managing

A board-certified dermatologist can assess your skin type, evaluate your goals, and recommend the most appropriate concentration, pH, and application schedule for your individual situation.

Frequently Asked Questions

Can glycolic acid damage your skin permanently?

When used at appropriate concentrations (2%–15%) with proper technique, glycolic acid does not cause permanent damage. However, misuse of high-concentration products (20%+) can cause chemical burns that result in permanent scarring or post-inflammatory hyperpigmentation. The key is respecting concentration limits and never exceeding recommended contact times.

Is glycolic acid safe for daily use?

For most people, yes - at concentrations of 2%–7% in a well-formulated product. Daily use at higher concentrations (10%+) increases the risk of chronic irritation and barrier damage. Even at lower concentrations, daily use should only follow a gradual buildup period. Not everyone needs to use glycolic acid daily; 3–4 times per week is effective for many people [1].

Does glycolic acid thin the skin?

This is a common concern but requires nuance. Glycolic acid thins the stratum corneum (the dead cell layer on top) by accelerating its shedding - this is the intended mechanism and is not harmful. At the same time, glycolic acid may increase the thickness of the living epidermis and stimulate collagen production in the dermis [5]. The net effect is thinner dead cell buildup on top but healthier, potentially thicker living skin underneath.

Can glycolic acid cause hyperpigmentation?

Paradoxically, yes. While glycolic acid is used to treat hyperpigmentation, it can also cause post-inflammatory hyperpigmentation (PIH) if it produces significant irritation - particularly in people with darker skin tones (Fitzpatrick IV–VI). The risk increases with higher concentrations, lower pH, and inadequate sun protection. This is why gradual introduction and daily sunscreen are especially important for people with melanin-rich skin.

What should I do if I had a bad reaction to glycolic acid?

Stop using the product immediately. Switch to a minimal routine: gentle cleanser, simple moisturizer, and sunscreen only. Avoid all active ingredients until your skin fully recovers (usually 1–2 weeks for mild reactions, longer for chemical burns). If you experience blistering, persistent pain, or discoloration, see a dermatologist. Once recovered, you may be able to try a lower concentration or a different AHA, but consult a professional first.

References

1. Sharad J. (2013). Glycolic acid peel therapy - a current review. Clin Cosmet Investig Dermatol. doi:10.2147/CCID.S34029Review
2. Kornhauser A, Wei RR, Yamaguchi Y, et al. (2009). The effects of topically applied glycolic acid and salicylic acid on ultraviolet radiation-induced erythema, DNA damage and sunburn cell formation in human skin. J Dermatol Sci. doi:10.1016/j.jdermsci.2009.03.011Controlled study
3. Tang SC, Yang JH. (2018). Dual Effects of Alpha-Hydroxy Acids on the Skin. Molecules. doi:10.3390/molecules23040863Review
4. Green BA, Yu RJ, Van Scott EJ. (2009). Clinical and cosmeceutical uses of hydroxyacids. Clin Dermatol. doi:10.1016/j.clindermatol.2009.06.023Review
5. Ditre CM, Griffin TD, Murphy GF, et al. (1996). Effects of alpha-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study. J Am Acad Dermatol. doi:10.1016/s0190-9622(96)80110-1Pilot clinical study
6. Bernstein EF, Lee J, Brown DB, et al. (2001). Glycolic acid treatment increases type I collagen mRNA and hyaluronic acid content of human skin. Dermatol Surg. doi:10.1046/j.1524-4725.2001.00234.xControlled study
7. Dreno B, Bissonnette R, Gagne-Henley A, et al. (2021). Safety review of skin care products for acne-prone skin. Clin Cosmet Investig DermatolReview
8. American Academy of Dermatology. (2023). Chemical Peels. AAD Patient Education ResourceClinical guideline

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