Glycolic Acid Cleanser
✓ Glycolic acid verified
The Ordinary Glycolic Acid 7% Exfoliating Toner
Glycolic acid: 7%
Glycolic Acid vs Vitamin C: Can You Use Both?
We independently evaluate products — verifying the ingredient list for every pick, and never accepting paid placement. Amazon links earn us a commission at no cost to you.
How we research · Affiliate disclosure →
You've probably seen glycolic acid and vitamin C recommended everywhere — and now you're wondering whether to pick one or use both. The confusion is understandable. Both are used for brightening and evening skin tone, and both show up in "best anti-aging ingredients" lists constantly.
Here's the short answer from the sources we read: they are documented doing different things, and no study tests using them together in a routine. Glycolic acid is an exfoliant that loosens dead skin cells. Vitamin C is an antioxidant that also plays a part in collagen formation. Most layering rules you will see online for the pair are not backed by any source we could find, so this page separates what is sourced from what is our own suggestion.
Glycolic Acid vs Vitamin C at a Glance
| Factor | Glycolic Acid | Vitamin C |
|---|---|---|
| What it does | Helps loosen the connection holding dead skin cells together (Cleveland Clinic) | Antioxidant that neutralizes free radicals and is a cofactor in collagen formation (Pullar 2017 review) |
| How it affects pigment | Encourages shedding of surface cells (DermNet NZ); inhibited tyrosinase in a 2003 cell study | Interferes with tyrosinase, the melanin enzyme (Telang review; the exact mechanism is described as proposed in the Pullar review) |
| Evidence for dark spots | 70% peel improved melasma in 14 women (Sobhi 2012) | Vitamin C iontophoresis did better in the same study; a 2002 pilot of a product with ascorbyl glucosamine found no effect on sun spots |
| pH | FDA/CIR conclusion: pH 3.5 or higher; most OTC products about pH 4 (Medical News Today) | L-ascorbic acid must be below pH 3.5 to enter skin (Pinnell 2001) |
| Sun sensitivity | The FDA says AHAs may increase it | No sun-sensitivity warning in sources we read; antioxidant photoprotection shown in pig skin (Darr 1992) |
| Time of day | Cleveland Clinic: night | Sources differ; Telang says best after UV exposure, not before. No source gives a time of day. |
| Frequency | Cleveland Clinic: start once or twice a week, build to nightly if tolerated | Skin levels saturated after three daily applications and fell with a half-life of about 4 days in pig skin (Pinnell) |
| Tolerability | Cleveland Clinic advises caution with sensitive skin, dry skin, rosacea and eczema | Telang's review calls the safety profile excellent; minor effects include yellowish skin discoloration |
What Is Glycolic Acid?
Glycolic acid is the smallest alpha hydroxy acid (AHA) and, Cleveland Clinic says, comes from sugarcane. Cleveland Clinic says that small size lets it penetrate deeper than other AHAs.
Cleveland Clinic says it helps loosen the connection that holds dead skin cells together on the surface, and DermNet NZ says that lets dead skin peel off gently, leaving skin underneath with a fresher look and more even colour and texture. Cleveland Clinic lists collagen stimulation among its effects, and a 2006 study in Japanese volunteers found collagen I and procollagen I increased in the upper dermis after 6 weeks of daily use.
The trade-off: the FDA says AHAs may increase skin sensitivity to the sun and advises sun protection. The study it cites tested 10% glycolic acid on 29 people, and the effect reversed within a week of stopping. For a deeper look at how different concentrations work, see our percentage guide.
What Is Vitamin C?
Vitamin C (ascorbic acid) is an antioxidant that normal skin contains in high concentrations, per a 2017 review in Nutrients. The same review says exposure to pollutants or UV irradiation is associated with depleted vitamin C in the outer skin layer, and a 1992 pig-skin study found UV irradiation severely depleted skin vitamin C. The claim that levels decline with age is not one we could source.
Its best-documented job is neutralizing free radicals: the Telang review says UV light generates reactive oxygen species and vitamin C neutralizes them by donating electrons. On pigment, the Telang review says vitamin C interacts with copper ions at the tyrosinase active site, decreasing melanin formation, while the Pullar review says vitamin C derivatives decreased melanin synthesis in cultured melanocytes and in vivo and describes the mechanism as proposed.
None of the sources we read describes vitamin C as an exfoliant, so it is not documented to remove dead cells or unclog pores. What it is documented to do is support collagen formation, since both reviews describe it as a cofactor for the enzymes that stabilize collagen, and to neutralize oxidants from UV and pollution. The Pullar review notes it is only one part of the skin's antioxidant defences and works especially well with vitamin E.
A note about forms: L-ascorbic acid is the form the studies measured, and it is unstable. Pinnell's 2001 pig-skin study found it must be formulated below pH 3.5 to enter the skin and that 20% was the maximum concentration for optimal absorption. On derivatives, the sources disagree: the Telang review calls magnesium ascorbyl phosphate the most stable ascorbyl ester and says it is easily absorbed, the Pullar review says phosphate derivatives are poorly absorbed and the conversion rate of ascorbyl glucoside is unknown, and in Pinnell's study magnesium ascorbyl phosphate did not raise skin L-ascorbic acid levels. We do not claim a derivative is gentler or easier to layer.
When to Use Glycolic Acid Instead of Vitamin C
No source we read compares them for these concerns, so this section says what each has evidence for and labels our own reading:
- Rough, bumpy texture — Cleveland Clinic lists removing dead skin cells among glycolic acid's effects. No source we read describes vitamin C as addressing texture directly.
- Clogged pores and dullness — Cleveland Clinic lists cleaning out clogged pores and brightening skin among glycolic acid's effects. Vitamin C is not described as unclogging pores.
- Dark spots — both have evidence. In the 2012 melasma study of 14 women, both a 70% glycolic acid peel and vitamin C iontophoresis improved melasma, with the vitamin C side doing better. That used clinic delivery methods, not cosmetic serums. The idea that glycolic acid removes pigmented cells vitamin C cannot reach is our reasoning, not a finding. Our dark spots guide sets out the evidence for post-acne marks, sun spots and melasma separately.
- Keratosis pilaris or rough body skin — glycolic acid has trial data in KP at clinic strength (a 2021 trial using 50% or 70%); we found none for vitamin C. See our KP guide for specific product recommendations.
Important: Glycolic acid may increase UV sensitivity. The FDA advises sun protection with AHAs and Cleveland Clinic advises broad-spectrum sunscreen of SPF 30 or higher, reapplied every two hours.
When to Use Vitamin C Instead of Glycolic Acid
Again, the sources do not rank the two. Here is what is documented, with our reading labelled:
- Sun damage prevention — the Telang review says vitamin C does not absorb UV light but neutralizes the free radicals it generates, and recommends sunscreen combined with a topical antioxidant; it says sunscreens alone block only about 55% of the free radicals UV produces. A 1992 pig-skin study found topical vitamin C protected against UVB damage. We found no source that vitamin C boosts sunscreen's effectiveness, so we do not claim it, and glycolic acid is described as increasing sun sensitivity by the FDA.
- Post-inflammatory hyperpigmentation — the Telang review says vitamin C has potential anti-inflammatory activity and can prevent post-inflammatory hyperpigmentation. That is a review's statement, and a 2002 pilot of one ascorbyl-glucosamine formulation found no effect on sun spots. On glycolic acid, the AAD says never to exfoliate over open cuts or wounds or sunburned skin, and Medical News Today says strong or irritating products can themselves cause hyperpigmentation.
- Sensitive skin that can't tolerate acids — the Telang review calls vitamin C's safety profile excellent, but no source we read compares its tolerability with glycolic acid, so which is gentler for your skin is our reading, not a finding. Cleveland Clinic advises caution with glycolic acid for sensitive skin.
- Pollution-heavy environments — the Pullar review says vitamin C can neutralize oxidants such as those in environmental pollutants. We found no source on glycolic acid and pollution.
Can You Use Glycolic Acid and Vitamin C Together?
Probably, and here is what we could and could not source.
You will read everywhere that the two "conflict" because of pH, and equally that they are "chemically compatible because they work at the same pH". We found no source for either. What the sources give are separate numbers: Pinnell's study found L-ascorbic acid must be formulated below pH 3.5 to enter the skin, the FDA reports the Cosmetic Ingredient Review conclusion covers glycolic acid at pH 3.5 or higher, and Medical News Today says most over-the-counter glycolic acid products are around pH 4. Nothing we read tests what happens when you apply one after the other.
The practical concern the sources do support is irritation and not knowing the cause: Cleveland Clinic advises that when you are first starting out you may want to avoid using glycolic acid with vitamin C serums, and says reducing the number of actives helps you isolate what causes an issue if your skin reacts. A review mentions a study where daily vitamin C combined with 20% glycolic acid over 3 months improved stretch marks, so use together is not unheard of, but we know that study only through the review.
The three approaches below are our suggestions, not tested regimens. We found no source that most dermatologists recommend the AM/PM split.
Strategy 1: AM/PM Split
- Morning: Cleanser → vitamin C serum → moisturizer → sunscreen
- Evening: Cleanser → glycolic acid toner or treatment → moisturizer
Why we suggest it: it keeps the two apart, which matches Cleveland Clinic's reasoning about isolating causes, and glycolic acid goes at night as Cleveland Clinic advises. Whether morning is the best time for vitamin C is not settled, since the Telang review says it is best used after UV exposure rather than before.
Strategy 2: Alternate Days
If your skin is sensitive or you are new to both, you can keep them on different days.
- Day 1: Vitamin C
- Day 2: Glycolic acid
- Day 3: Vitamin C
This leaves a gap between actives. No source we read gives a timeline for moving to same-day use.
Strategy 3: Same Routine
For experienced users only, and untested: introduce one product at a time and watch for irritation. No source we read gives a wait time. Our layering guide covers this same-routine approach in more depth, alongside the other actives people commonly try to combine with glycolic acid.
Important: If you experience stinging, redness, or peeling after combining glycolic acid and vitamin C, stop one of them and let your skin recover. The AAD says over-exfoliating can leave skin red and irritated, and Cleveland Clinic advises using fewer actives so you can tell what is causing a reaction.
Vitamin C form and layering. As above, the sources disagree about derivatives, and none tests them under a glycolic acid product. We do not claim that one form is gentler to layer.
Best Glycolic Acid Products to Pair with Vitamin C
Since this page focuses on glycolic acid, here are our top picks for the glycolic acid half of your routine. For vitamin C serums, the Pinnell study found 20% was the maximum concentration for optimal absorption, and the Telang review says L-ascorbic acid oxidizes in light, so sealed, opaque packaging follows from that.
Best glycolic acid toner for the PM side of an AM vitamin C routine
The Ordinary's 7% Glycolic Acid Toning Solution sits under the 10% ceiling that the FDA reports the Cosmetic Ingredient Review panel concluded is safe for consumer products. Cleveland Clinic advises starting glycolic acid once or twice a week and using it at night. We have not tested the product.
Best glycolic acid cleanser for a low-commitment vitamin C pairing
✓ Glycolic acid verified
L'Oreal Paris Revitalift 3.5% Pure Glycolic Acid Brightening Cleanser
Glycolic acid: 3.5%
If you'd rather keep your glycolic acid in the cleansing step, L'Oréal's Revitalift cleanser lists 3.5% glycolic acid. Medical News Today says leave-on formulas give the acid more time to work, so our reading is that a rinse-off formula exposes skin for less time, though we found no study measuring that. It is a lower-commitment way to try glycolic acid alongside a vitamin C routine.
Best glycolic acid toner for reactive skin starting vitamin C
✓ Glycolic acid verified
Good Molecules Glycolic Exfoliating Toner
Glycolic acid: 3.5%
Good Molecules lists 3.5% glycolic acid, half the strength of The Ordinary's 7%. If your skin is reactive, or you are nervous about adding glycolic acid next to vitamin C, a lower strength is a more cautious start, which is our reading rather than a tested result. Cleveland Clinic advises starting once or twice a week and building up only if your skin tolerates it.
Common Mistakes When Combining Glycolic Acid and Vitamin C
Starting both at once. Cleveland Clinic advises that when first starting out you may want to avoid using glycolic acid with vitamin C serums, and says using fewer actives lets you isolate what causes an issue. A 15–20 minute buffer is often called essential, but no source we read gives one.
Stacking strong versions of both. A high-strength glycolic acid product followed by a high-strength L-ascorbic acid serum is an intense combination, which is our caution rather than a tested finding. The sourced bounds are the 10% the FDA reports for consumer glycolic acid products and the 20% maximum in Pinnell's study; if you want to try them together, lowering one is the cautious choice.
Skipping sunscreen because "vitamin C protects from the sun." The Telang review says vitamin C does not absorb UV light and recommends combining sunscreen with a topical antioxidant, not replacing it, and the FDA says AHAs may increase sun sensitivity. Cleveland Clinic advises broad-spectrum sunscreen of SPF 30 or higher.
Adding retinol to the mix. Cleveland Clinic advises avoiding retinol with glycolic acid when first starting out, and its retinol page says to consider alternating days or using glycolic acid in the morning and retinol at night. See our glycolic acid vs retinol guide for how to alternate them.
Expecting overnight results. Cleveland Clinic says over-the-counter glycolic acid products may take several months of consistent use before skin looks brighter or pigmentation more even. We found no source giving a timeline for vitamin C serums.
Frequently Asked Questions
Can we use glycolic acid and vitamin C together?
Probably, but no source we read tests layering them. Cleveland Clinic says that when you are first starting out you may want to avoid using glycolic acid with vitamin C serums, so you can tell what causes a reaction if your skin is sensitive. A review of vitamin C in dermatology mentions a study in which daily vitamin C combined with 20% glycolic acid over 3 months improved stretch marks; we know it only through the review. Vitamin C in the morning and glycolic acid at night is our suggestion for keeping the two apart; it is not a tested regimen, and no source we read gives a wait time between the two.
What to apply first, glycolic acid or vitamin C?
No source we read gives an order or a wait time, and none supports the claims that glycolic acid should go first, that it helps vitamin C absorb better, or that you should wait 15–20 minutes for your skin's pH to rebalance. What is sourced is about vitamin C's own formulation: a 2001 pig-skin study from Duke University found L-ascorbic acid must be formulated at a pH below 3.5 to enter the skin, with 20% the maximum concentration that improved absorption. That describes the serum, not how it interacts with a glycolic acid product applied earlier.
Does glycolic acid cancel out vitamin C?
We found no source showing that either deactivates the other, and none showing they are chemically compatible; the common statement that they work in the same pH range is not one we could source. What the sources do say: Pinnell's study found L-ascorbic acid must be below pH 3.5 to enter the skin, while the FDA reports the Cosmetic Ingredient Review panel's conclusion covers glycolic acid products at pH 3.5 or higher, and Medical News Today says most over-the-counter glycolic acid products are around pH 4. The Telang review calls L-ascorbic acid unstable, particularly in light, and says it oxidizes to a yellow compound. Irritation from stacking two acids is the practical concern, but that too is our reading rather than a tested finding.
Is glycolic acid or vitamin C better for dark spots?
Both have some evidence and one small trial compares them. In a 2012 Egyptian study of 14 women with melasma, skin types IV–V, one side was treated with a 70% glycolic acid peel and the other with nanosome vitamin C by iontophoresis over six sessions; both sides improved and the vitamin C side did better. That used a clinic delivery method, not a cosmetic serum. Against that, a 2002 pilot of 50 women with sun spots found a formulation containing 5% ascorbyl glucosamine, 1% kojic acid and AHA esters appeared inefficacious. For mechanism, glycolic acid inhibited tyrosinase in a 2003 cell study, and a 2017 review says vitamin C derivatives decreased melanin synthesis in cultured melanocytes and in vivo. No source tests whether using both gives the fastest results.
Can vitamin C replace glycolic acid?
Not on the evidence we read, though they overlap on pigment. Cleveland Clinic describes glycolic acid as helping loosen the connection that holds dead skin cells together, while the 2017 review describes vitamin C chiefly as an antioxidant that also acts as a cofactor in collagen formation. Neither source describes vitamin C as an exfoliant. For melasma, the 2012 study above found both worked. If you can only pick one, choosing by your main concern is our reading, not a sourced rule.
Is glycolic acid or vitamin C better for wrinkles?
No source we read compares them. For glycolic acid, Cleveland Clinic lists stimulating collagen production among its effects, and a 2006 study in Japanese volunteers found collagen I and procollagen I increased in the upper dermis after 6 weeks of daily use. For vitamin C, the Telang review says it is a cofactor for the enzymes that stabilize collagen and that it increases collagen production in young and aged skin. Both are plausible contributors; the claims that glycolic acid works by accelerating cell turnover for existing lines and that vitamin C prevents new wrinkles are not ones we could source.
Should I use vitamin C in the morning or at night?
The sources do not settle it. The Telang review says vitamin C does not absorb UV light but neutralizes free radicals, and recommends sunscreen combined with a topical antioxidant; it also says that because UV lowers skin vitamin C levels, topical vitamin C is best used after UV exposure and not before. A 1992 pig-skin study found topical vitamin C protected against UVB damage. We found no source saying vitamin C enhances sunscreen's effectiveness. For glycolic acid, Cleveland Clinic says it should be used at night because it increases sun sensitivity. A morning vitamin C and evening glycolic acid split is a common convention and our suggestion, not a sourced rule.
What can you not mix with glycolic acid?
No source we read says never, but Cleveland Clinic advises that when you are first starting out you may want to avoid using glycolic acid with other exfoliants such as lactic and salicylic acids, retinol, and vitamin C serums. The AAD says retinol, retinoids and benzoyl peroxide can make skin more sensitive or peeling, and that exfoliating while using them may worsen dryness or cause breakouts. The AAD also advises moisturizing right after exfoliating, and the FDA advises sun protection with AHAs. We found no source for a morning-and-evening split for vitamin C specifically, so that is our suggestion.
Is glycolic acid better than vitamin C?
No source we read ranks them. They are documented doing different things: glycolic acid loosens the bonds between dead skin cells (Cleveland Clinic), while vitamin C is, per the 2017 review, a potent antioxidant that is only one of the skin's defences and that works best alongside vitamin E. The claims that glycolic acid is a stronger exfoliant and vitamin C a stronger antioxidant are comparisons nobody measured, and the idea that glycolic acid wins for resurfacing and vitamin C for protection is our reading. Using both is possible but untested together.
Can I layer glycolic acid and vitamin C?
No source we read tests it, so treat this as caution rather than a rule. Cleveland Clinic advises avoiding vitamin C serums with glycolic acid when you are first starting out. On forms, the sources disagree. The Telang review calls magnesium ascorbyl phosphate the most stable ascorbyl ester and says it is easily absorbed; the 2017 review says phosphate derivatives are converted slowly and poorly absorbed, and that the conversion rate of ascorbyl glucoside is unknown; and in Pinnell's pig-skin study, magnesium ascorbyl phosphate and other derivatives did not raise skin L-ascorbic acid levels. We found no source that a derivative is gentler when layered. If you try same-session use, our suggestion is to introduce one product at a time.
What cancels out vitamin C serum?
Oxidation is the documented risk: the Telang review says L-ascorbic acid is unstable, that light oxidizes it to dehydroascorbic acid, which turns it yellow, and that stability is controlled by keeping the pH below 3.5. Keeping a serum sealed and away from light follows from that; discarding it when it changes colour is our precaution. We found no source on glycolic acid deactivating vitamin C, and none supporting the idea that niacinamide does or does not, so we make neither claim. See our glycolic acid vs niacinamide guide for what we could and couldn't source about niacinamide.