Building a Glycolic Acid Routine

A glycolic acid routine works best when you apply it in the evening on clean, dry skin, follow it with a moisturizer, and wear SPF 30+ sunscreen every morning without exception. Start at 2–3 applications per week and increase gradually over 4–8 weeks. This approach - evening application, slow frequency ramp, mandatory sun protection - is not arbitrary. It is grounded in evidence showing that glycolic acid increases UV sensitivity by approximately 18% during use [1] and that skin cell turnover naturally accelerates during sleep.

When to Apply: Why PM Is Preferred

Most dermatologists recommend evening application for two evidence-based reasons.

UV sensitivity. Glycolic acid increases the skin's susceptibility to ultraviolet radiation. Kaidbey et al. (2003) demonstrated in a randomized, double-blind study that four weeks of daily 10% glycolic acid application increased UV sensitivity by 18%, measured by the minimal erythema dose (MED) [1]. Kornhauser et al. (2009) confirmed that glycolic acid increases UV-induced erythema, DNA damage, and sunburn cell formation in human skin [2]. Applying the acid at night means it works during the hours when UV exposure is zero, maximizing the benefit-to-risk ratio.

Nighttime cell turnover. Epidermal cell renewal naturally accelerates during sleep. Applying glycolic acid in the evening aligns with this biological rhythm, supporting the exfoliation process when the skin is already in repair mode.

Can you use glycolic acid in the morning? Yes, but only if you are rigorous about sunscreen. Low-concentration products (cleansers, light toners at 5% or below) can be used in the morning provided you apply and reapply broad-spectrum SPF 30+ sunscreen. If your sunscreen compliance is inconsistent, morning use adds unnecessary risk.

Application Order: Where Glycolic Acid Fits

Your skincare routine should follow a general principle: thinnest, most active products go first, thicker products go last. Here is where glycolic acid fits in a complete evening and morning routine.

Evening Routine (Glycolic Acid Night)

1. Cleanser - A gentle, pH-balanced cleanser. Massage onto damp skin for 30–60 seconds, rinse, and pat dry. If you wear makeup or sunscreen, double-cleanse (oil cleanser first, then water-based cleanser).

2. Glycolic acid product - Apply to clean, dry skin. Wait 30 seconds after cleansing to ensure skin is fully dry - water can dilute the acid and cause it to pool in skin folds, leading to uneven irritation. Use the amount directed on the product label (typically 3–5 drops for a serum, or a saturated cotton pad for a toner). Avoid the eye area and lips.

3. Wait 1–2 minutes - Let the glycolic acid absorb before layering the next product.

4. Serum (optional) - If you use a niacinamide, hyaluronic acid, or peptide serum, apply it now. These ingredients are compatible with glycolic acid and add complementary benefits.

5. Moisturizer - A gentle, fragrance-free moisturizer containing ceramides, glycerin, or hyaluronic acid. This serves as both a hydrating step and a buffer against potential irritation from the glycolic acid. Should you moisturize after glycolic acid? Absolutely - moisturizing after glycolic acid is one of the most important steps in the routine. It replenishes the lipid barrier, locks in hydration, and reduces the stinging and dryness that glycolic acid can cause, especially during the first few weeks of use.

6. Occlusive (optional) - If you have dry skin or are in a dry climate, a thin layer of an occlusive product (such as a sleeping mask or squalane oil) seals in the previous layers.

Morning Routine (The Day After)

1. Cleanser - A gentle morning cleanse. Some people prefer just rinsing with water in the morning.
2. Vitamin C serum (optional) - If you use L-ascorbic acid, morning is the ideal time (see layering section below).
3. Moisturizer - Lightweight, hydrating.
4. Sunscreen (SPF 30+) - This is the single most important step in any routine that includes glycolic acid. Apply generously (about 1/4 teaspoon for the face) and reapply every 2 hours if you are outdoors for extended periods. Skipping sunscreen while using glycolic acid increases your risk of sunburn, hyperpigmentation, and accelerated photoaging - the exact opposite of what you are trying to achieve.

Frequency Guidelines by Experience Level

How often you use glycolic acid should match your experience and your skin's demonstrated tolerance. Pushing frequency too fast is the most common mistake, and it leads to barrier damage, not faster results.

Beginner (First 8 Weeks)

• Weeks 1–2: 2 times per week (e.g., Monday and Thursday evenings)
• Weeks 3–4: If no persistent redness, stinging, or flaking beyond the first few minutes, increase to 3 times per week
• Weeks 5–8: Gradually increase to every other day, then daily if tolerated

Use a 5%–7% concentration. A toner or lightweight serum is the best format for beginners because it provides consistent, measurable exfoliation. For detailed concentration guidance, see our concentration guide.

Intermediate (2–4 Months)

• Frequency: Daily or near-daily use of 5%–10% products
• Optional addition: A weekly at-home mask or peel (10%–15%) for a deeper exfoliation boost
• Adjustment: On the day you use a mask or peel, skip your daily glycolic acid product to avoid double-dosing

At this stage, you should have a clear sense of your skin's tolerance. If you experience occasional mild dryness, adjust by reducing to every other day for a week rather than stopping entirely.

Advanced (4+ Months)

• Frequency: Daily use of 8%–10% products
• Optional addition: Weekly or biweekly at-home peel (15%–20%), or periodic professional peels (20%–70%) every 4–6 weeks
• Maintenance approach: Many experienced users find a sustainable long-term routine involves daily low-concentration use with occasional higher-concentration treatments

Even advanced users should continue monitoring for signs of over-exfoliation and maintain daily sunscreen use. Long-term use does not make your skin immune to acid damage.

What to Layer with Glycolic Acid

Certain ingredients complement glycolic acid and are safe - even beneficial - to use in the same routine.

Niacinamide (Safe and Beneficial)

Niacinamide (vitamin B3) is one of the best companions for glycolic acid. It strengthens the skin barrier, reduces redness and inflammation, improves hyperpigmentation, and minimizes pore appearance. There was an older concern that niacinamide and acids react at low pH to form niacin (which causes flushing), but this reaction requires sustained high temperatures far beyond what occurs on skin. Modern research confirms that niacinamide and glycolic acid are safe and beneficial to use together [3].

How to layer: Apply glycolic acid first, wait 1–2 minutes, then apply a niacinamide serum. Alternatively, use a moisturizer that contains niacinamide as your post-acid step.

Hyaluronic Acid (Safe and Beneficial)

Hyaluronic acid is a humectant that draws water into the skin. It does not interact chemically with glycolic acid and helps offset the dryness that glycolic acid can cause. Applying hyaluronic acid after glycolic acid provides immediate hydration to freshly exfoliated skin.

How to layer: Apply glycolic acid, wait 1–2 minutes, then apply hyaluronic acid serum to slightly damp skin (mist your face with water first for best results). Follow with moisturizer.

Ceramides (Safe and Beneficial)

Ceramides are lipid molecules that form the skin's natural barrier. A ceramide-containing moisturizer used after glycolic acid supports barrier integrity and reduces the dryness and irritation that can accompany exfoliation. This is especially important during the tolerance-building phase when your skin is adjusting to the acid.

How to layer: Apply ceramide-containing moisturizer as the last step after glycolic acid and any serums.

Peptides (Generally Safe)

Peptide serums are stable at the pH range used by glycolic acid products. They can be layered after glycolic acid in the same routine. Apply the glycolic acid first, let it absorb, then apply the peptide serum.

Azelaic Acid (Safe on Different Days)

Azelaic acid is an effective treatment for rosacea, acne, and hyperpigmentation. It can be used alongside glycolic acid, but layering them in the same routine step may cause irritation for some people. The simplest approach is to alternate: glycolic acid one evening, azelaic acid the next.

What NOT to Layer with Glycolic Acid

Some ingredients should not be applied at the same time as glycolic acid because the combination amplifies irritation or reduces efficacy.

Retinoids (Alternate Nights)

Both glycolic acid and retinoids (retinol, tretinoin, adapalene) increase cell turnover and can compromise the skin barrier. Using them together in the same evening significantly amplifies irritation risk. For a full breakdown, see our glycolic acid vs retinol comparison. The standard dermatological recommendation is to alternate evenings: glycolic acid one night, retinoid the next [4].

After months of building tolerance to each ingredient individually, some experienced users can tolerate both in the same routine - applying glycolic acid first, waiting 20–30 minutes, then applying the retinoid. But this is an advanced strategy that should be approached with caution and is not recommended for most people.

Schedule example:

• Monday: Glycolic acid
• Tuesday: Retinoid
• Wednesday: Glycolic acid
• Thursday: Retinoid
• Friday: Glycolic acid
• Saturday: Neither (recovery)
• Sunday: Retinoid

Vitamin C (Use at Different Times of Day)

High-concentration vitamin C (L-ascorbic acid at 15%–20%) is formulated at low pH, similar to glycolic acid. Layering two low-pH actives can overwhelm the skin, causing stinging, redness, and irritation. The simplest and most effective approach is to use vitamin C in the morning (where it provides antioxidant protection against environmental damage) and glycolic acid in the evening.

How to separate: Vitamin C serum in your AM routine, glycolic acid in your PM routine. This gives you the benefits of both without the irritation of layering them.

Other AHAs and BHAs (Do Not Stack)

Layering glycolic acid with salicylic acid, lactic acid, mandelic acid, or other exfoliating acids in the same routine step is a common cause of over-exfoliation. The combined acid exposure exceeds what most skin can tolerate, leading to redness, peeling, and barrier damage.

If you want to use multiple acids, separate them by time: use glycolic acid on some evenings and salicylic acid on others. For a detailed comparison of glycolic acid and salicylic acid, including combination strategies, see our comparison guide.

Physical Scrubs (Not on the Same Day)

Using a physical exfoliant (scrub, brush, washcloth) on the same day as a glycolic acid treatment provides double exfoliation that is unnecessary and risky. Chemical exfoliation (glycolic acid) and physical exfoliation target the same outcome - removing dead surface cells. Doing both at once significantly increases the chance of micro-tears and irritation. If you want to use a physical exfoliant, schedule it on a day when you are not using glycolic acid.

Benzoyl Peroxide (Separate Steps, Use with Caution)

Benzoyl peroxide is an effective acne treatment, but it is an oxidizer that can potentially deactivate certain formulations when applied simultaneously with glycolic acid. If you use both, apply them at different times (benzoyl peroxide in the morning, glycolic acid in the evening) or on alternating days.

For a complete reference of ingredient interactions, use our Interaction Checker.

Building Tolerance: A Week-by-Week Schedule

This eight-week ramp-up schedule is designed for someone starting glycolic acid for the first time with a 5%–7% leave-on product (toner or serum).

Weeks 1–2: Introduction

| Day | PM Routine | |---|---| | Monday | Cleanser, glycolic acid, moisturizer | | Tuesday | Cleanser, moisturizer only | | Wednesday | Cleanser, moisturizer only | | Thursday | Cleanser, glycolic acid, moisturizer | | Friday–Sunday | Cleanser, moisturizer only |

What to watch for: Mild tingling (1–5 minutes) is normal. Minor redness that resolves within an hour is normal. Slight dryness is normal and manageable with extra moisturizer.

Weeks 3–4: Building

| Day | PM Routine | |---|---| | Monday | Cleanser, glycolic acid, moisturizer | | Wednesday | Cleanser, glycolic acid, moisturizer | | Friday | Cleanser, glycolic acid, moisturizer | | Other days | Cleanser, moisturizer only |

Checkpoint: At the end of week 4, your skin should be showing less tingling and no persistent redness. If you are still experiencing significant irritation, stay at twice per week for 2 more weeks before increasing.

Weeks 5–6: Escalation

| Day | PM Routine | |---|---| | Monday | Cleanser, glycolic acid, moisturizer | | Tuesday | Cleanser, moisturizer only | | Wednesday | Cleanser, glycolic acid, moisturizer | | Thursday | Cleanser, moisturizer only | | Friday | Cleanser, glycolic acid, moisturizer | | Saturday | Cleanser, moisturizer only | | Sunday | Cleanser, glycolic acid, moisturizer |

This is every-other-day application. Most people find this frequency sustainable long-term with a 5%–7% product.

Weeks 7–8: Daily (If Tolerated)

| Day | PM Routine | |---|---| | Every evening | Cleanser, glycolic acid, moisturizer |

Not everyone needs daily use. If every-other-day application is giving you the results you want with no irritation, there is no need to increase to daily. More is not always better.

After 8 Weeks: Reassess

If you are comfortable with daily use at 5%–7% and want stronger results, consider stepping up to 8%–10%. When you increase concentration, drop back to 3 times per week and repeat the ramp-up process. For more detail on moving up in concentration, see our concentration guide.

Signs You Are Over-Exfoliating

Over-exfoliation is the most common mistake in a glycolic acid routine. It happens when you use too much acid, too often, or in combination with too many other actives. The signs include:

• Persistent redness that does not resolve between applications
• Increased sensitivity - products that previously felt fine now sting or burn
• Tight, dry, "plastic" feeling skin - the skin feels taut rather than plump
• Shiny, almost translucent appearance - this indicates the stratum corneum has been stripped beyond its capacity to regenerate
• Increased breakouts - compromised barrier function can actually increase acne rather than reduce it
• Stinging from gentle products - if your moisturizer or even water causes stinging, your barrier is compromised

How to Recover

If you recognize these signs, the protocol is straightforward:

1. Stop all actives immediately. No glycolic acid, no retinoids, no vitamin C, no other exfoliants.
2. Simplify your routine to three products only: gentle cleanser, ceramide-containing moisturizer, and sunscreen.
3. Focus on barrier repair for 1–2 weeks. Products with ceramides, cholesterol, and fatty acids help restore barrier function. Research shows that glycolic acid at appropriate concentrations does not permanently compromise the skin barrier [5], so recovery is achievable.
4. Reintroduce glycolic acid slowly after your skin has fully recovered. Start at a lower frequency than before (once or twice per week) and rebuild.

AM vs. PM: A Comparison

| Factor | AM Application | PM Application | |---|---|---| | UV risk | Higher - skin is UV-sensitized during active exposure hours | Lower - acid works overnight when UV is absent | | Sunscreen requirement | Absolutely critical (already mandatory, but even more so) | Still mandatory the following morning | | Cell turnover alignment | Does not align with natural repair cycle | Aligns with nighttime cell renewal | | Practical convenience | Adds a step before sunscreen; requires full absorption time | Fits naturally into an evening wind-down routine | | Compatible with vitamin C | Difficult - both compete for the low-pH application step | Easy - vitamin C goes in AM, glycolic acid in PM |

Bottom line: PM application is the evidence-based default. Use glycolic acid in the morning only if you have a specific reason (such as a retinoid occupying your PM routine every evening) and your sunscreen compliance is excellent.

Sample Complete Routines

Beginner Routine (Weeks 1–4)

PM (Glycolic acid nights, 2–3x/week): Gentle cleanser → 5% glycolic acid toner → Ceramide moisturizer

PM (Off nights): Gentle cleanser → Ceramide moisturizer

AM (Every day): Water rinse or gentle cleanser → Moisturizer → SPF 30+ sunscreen

Intermediate Routine (Months 2–4)

PM (Glycolic acid nights, daily or near-daily): Gentle cleanser → 8% glycolic acid serum → Niacinamide serum → Ceramide moisturizer

PM (One rest day per week, optional): Gentle cleanser → Niacinamide serum → Ceramide moisturizer

AM (Every day): Gentle cleanser → Vitamin C serum → Lightweight moisturizer → SPF 30+ sunscreen

Advanced Routine with Retinoid (Month 4+)

PM (Glycolic acid nights - Mon, Wed, Fri): Gentle cleanser → 10% glycolic acid serum → Hyaluronic acid serum → Ceramide moisturizer

PM (Retinoid nights - Tue, Thu, Sat): Gentle cleanser → Retinol or tretinoin → Ceramide moisturizer

PM (Recovery night - Sun): Gentle cleanser → Niacinamide serum → Rich moisturizer

AM (Every day): Gentle cleanser → Vitamin C serum → Lightweight moisturizer → SPF 50 sunscreen

Frequently Asked Questions

Should I apply glycolic acid to wet or dry skin?

Apply to dry skin. Water dilutes the acid and can cause it to pool in skin folds or around the nose, leading to uneven irritation. After cleansing, pat your face dry and wait 30 seconds before applying the glycolic acid product.

How long should I wait between glycolic acid and my next product?

Wait 1–2 minutes for absorption. The older advice of waiting 20–30 minutes is not necessary with modern formulations. The acid begins working on contact and does not need extended time before you layer other products.

Can I use glycolic acid every day?

Yes, many people use glycolic acid daily once they have built tolerance. But daily use is not required for good results. If every-other-day application is working for you, there is no clinical benefit to forcing daily use. The RCT by Abels et al. (2011) showed significant acne improvement with once-daily 10% glycolic acid application [6], but other studies have demonstrated results with less frequent application as well.

What if I miss a night?

Missing a single application has no meaningful impact. Glycolic acid works through consistent, repeated use over weeks and months - not through individual applications. Resume your normal schedule the next evening.

Can I use glycolic acid around my eyes?

Avoid the immediate eye area (eyelids and under-eye skin), which is thinner and more sensitive. If your product migrates during sleep, you may experience morning stinging. Some eye creams contain very low glycolic acid concentrations (1%–3%) specifically formulated for periorbital skin.

References

1. 1. Kaidbey K, et al. (2003). Topical glycolic acid enhances photodamage by ultraviolet light. Photodermatol Photoimmunol PhotomedRCT
2. 2. Kornhauser A, 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 Sciclinical trial
3. 3. Tang SC, Yang JH (2018). Dual Effects of Alpha-Hydroxy Acids on the Skin. Moleculesreview
4. 4. Sharad J (2013). Glycolic acid peel therapy - a current review. Clin Cosmet Investig Dermatolreview
5. 5. Fartasch M, Teal J, Menon GK (1997). Mode of action of glycolic acid on human stratum corneum: ultrastructural and functional evaluation of the epidermal barrier. Arch Dermatol Resin vitro study
6. 6. Abels C, et al. (2011). A 10% glycolic acid containing oil-in-water emulsion improves mild acne: a randomized double-blind placebo-controlled trial. J Cosmet DermatolRCT

Related Articles

usage

Choosing the Right Concentration

From 5% daily toners to 70% professional peels - find the right strength.

usage

Glycolic Acid for Different Skin Types

Tailored advice for oily, dry, sensitive, combination, and acne-prone skin.

fundamentals

What Is Glycolic Acid?

The complete guide to glycolic acid.

fundamentals

Glycolic Acid Side Effects

What to expect when starting glycolic acid and how to manage reactions.