Glycolic vs Salicylic vs Mandelic Acid: Which to Formulate
Glycolic vs salicylic acid comes down to where each one works. Glycolic is a small, water-soluble AHA for surface texture and dullness. Salicylic is an oil-soluble BHA that reaches into oily pores, for oil and congestion. Mandelic is a larger AHA (152 vs 76 g/mol) positioned as the gentler option. The right pick depends on who you sell to.
When you scope an exfoliant SKU, the first real decision is the acid. The three look interchangeable on a label, yet they behave differently in a formula and trigger different US and EU rules. This guide is for brands formulating with an OEM/ODM manufacturer.
Glycolic vs salicylic vs mandelic, in plain terms
All three are chemical exfoliants. They loosen the bonds between dead surface skin cells so those cells shed more evenly. The differences come down to the chemical family and the molecule itself.
AHAs (alpha hydroxy acids) are water-soluble and work mainly at the skin surface. Glycolic and mandelic are both AHAs. Salicylic is the BHA (beta hydroxy acid) of the group, and its oil solubility is its whole point. The PubChem numbers make the split concrete:
Glycolic acid: 76.05 g/mol, XLogP -1.1. The smallest and most water-loving of the three.
Mandelic acid: 152.15 g/mol, XLogP 0.6. About twice the molecular weight of glycolic.
Salicylic acid: 138.12 g/mol, XLogP 2.3. By far the most oil-loving of the three.
These acids are not ranked from worst to best. They are three different tools, and the right one matches your customer.
Glycolic vs salicylic acid: the side by side
The percentages below are typical leave-on starting points, not fixed rules. The right level depends on the full formula, the pH and the destination market.
Glycolic acid
Family and size: AHA, 76.05 g/mol (small)
Usually positioned for: dullness, rough-looking texture, resurfacing for more resilient skin
Typical starting point: around 5 to 10%
Regulatory note: the CIR conclusion cited by the FDA covers glycolic at 10% or less, final pH 3.5 or greater, with sun protection directions
Salicylic acid
Family and size: BHA, 138.12 g/mol (medium), oil-soluble
Usually positioned for: oily and congested-looking skin, visible pores, blackheads
Typical starting point: 0.5 to 2%
Regulatory note: a US OTC acne active at 0.5 to 2% (21 CFR 333.310); capped at 2% in most leave-on products under the EU Cosmetics Regulation
Mandelic acid
Family and size: AHA, 152.15 g/mol (large)
Usually positioned for: sensitive skin, uneven-looking tone, mild texture, first-time acid users
Typical starting point: around 5 to 10%
Regulatory note: the CIR condition names glycolic and lactic, not mandelic, so a mandelic formula's level and pH are set in development and testing
Oily, congested skin leans salicylic, visible resurfacing leans glycolic, and sensitive or acid-new customers often start with mandelic. Some ranges carry two acids for two jobs.
Which penetrates deeper?
"Deeper" is the wrong frame. Glycolic is the smallest molecule, so it moves readily through the water-based surface layers. Salicylic is oil-soluble, so it can travel into an oil-filled pore, which water-soluble AHAs do not do as well. They reach different places for different reasons, and neither depth belongs in a claim.
Where mandelic fits
Mandelic acid is an AHA, not a BHA. It is more lipophilic than glycolic (XLogP 0.6 vs -1.1) but far less than salicylic (2.3), so it should not be called oil-soluble. A dermatology review (Dermatology Review, Termedia) describes its large molecule as absorbed slowly through the skin, which tends to make it less irritating. So mandelic vs glycolic usually lands on mandelic for a gentle, sensitive-skin position, and mandelic vs salicylic is surface tolerance versus oil and pore focus. For the single-acid view, see mandelic acid in skincare.
Can you use glycolic and salicylic acid together?
There are two answers, and a brand needs both.
In a routine. Many lines sell a glycolic product and a salicylic product side by side for different concerns. That is a merchandising decision, and the directions for use should be clear and conservative.
In one formula. Two acids in one product change the pH and the total acid load. The CIR condition for glycolic (10% or less at pH 3.5 or greater) applies to the finished product, so a blend is designed as a whole. The same logic covers mandelic with salicylic and mandelic with glycolic. A combination is tested in sampling for pH, stability and sensory feel rather than assumed.
Whether an acid product sits alongside retinoids or other strong actives is a label and directions question for your regulatory review, not something to settle in marketing copy.
Where niacinamide fits
Niacinamide shows up in the same searches ("salicylic acid vs glycolic acid vs niacinamide"), but it is not an exfoliating acid. It is the common supporting ingredient in an acid line, in the same formula or a companion SKU. Our niacinamide formulation guide covers it as its own active.
Lactic and PHA: the other options a brief may mention
The FDA names glycolic and lactic acid as the most common AHAs in cosmetics, and the CIR conclusion it cites covers both. So lactic is a familiar alternative when a brief wants an AHA other than glycolic. PHA (polyhydroxy acid) is another option some briefs raise, and we treat it as its own formulation discussion.
Why brands are launching acid SKUs
An acid SKU maps cleanly to a customer concern and works in many formats. For most brands it works best as a hero SKU with a hydration story around it, not three competing acids at once. A common rollout is one acid serum or toner first, then a second format once the first proves out.
Claims, labels and the cosmetic vs drug line
Acids are positioned around smoother-looking texture, brighter and more even-looking tone, and clearer-looking skin. The risk is drifting into drug language. Use this framing as a starting point, then have it reviewed for your specific market:
Cosmetic, defensible: "Gently exfoliates for smoother, brighter-looking skin." Fits most markets, with substantiation.
Cosmetic, needs support: "Helps visibly even the look of tone and refine texture." Possible, with evidence and careful phrasing.
Drug or medical territory: "Treats acne", "heals blemishes", "repairs the skin barrier." Not a cosmetic claim.
Three rules shape most acid labels:
US salicylic. Under 21 CFR 333.310, salicylic acid at 0.5 to 2% is an OTC acne active, so a salicylic product that claims to treat acne is an OTC drug. A cosmetic toner that talks about clearer-looking, less congested-looking skin is a much simpler project.
US AHAs. FDA guidance recommends a "Sunburn Alert" statement: the AHA may increase sun sensitivity, so use sunscreen, wear protective clothing and limit sun exposure while using the product and for a week afterwards.
EU salicylic. The EU Cosmetics Regulation caps salicylic acid at 2% in most leave-on products.
Formulating an acid line: formats, pH and pairings
Hong Shin formulates mandelic, glycolic and salicylic across the formats buyers expect:
Serums and ampoules, the usual hero format for a targeted percentage
Toners and essences for a daily, lower-percentage entry SKU
Exfoliating pads, wash-off masks and cleansers
Body formats, such as body lotion and body wash
Blends, such as a low mandelic plus salicylic combination, tested in sampling
A real formulation conversation covers more than the headline percentage: pH (an acid at the wrong pH is either inactive or harsh), the rest of the actives stack, fragrance and preservative choices, sensory feel and stability. That is decided in the lab, then proven through stability testing, compatibility and PET (preservative efficacy) testing. If mandelic is your lead, our private label mandelic acid serum guide walks through that build.
How an acid launch works with Hong Shin
Hong Shin Cosmetics is a Canadian-owned contract manufacturer with Taipei HQ, established in 2012, with 13+ years of operation and customers in 16 countries. Products are made in Taiwan and South Korea. We work as private label, OEM/ODM (custom formulation, in-house R&D, IP-exclusive) or wholesale, and can take a formula transfer from your own formulator.
Brief and NDA. You share the concept, target market and rough volumes.
Quote and spec, within 5 business days of the brief.
Sampling. Lab samples, stability testing, packaging mockups and sign-off. The acid, percentage and pH are set here.
Pilot run. The first commercial batch, with QC and a COA per batch.
Ship and scale, on FOB Taiwan or DDP terms.
Commercial terms for a first acid project:
First-run MOQ: 1,500 units per SKU on the Taiwan route, 3,000 units per SKU on the South Korea route (SPF serums and cream serums route to Korea).
Lead time: 10 to 12 weeks from formula sign-off on the Taiwan route, for retail bottles, tubes and jars.
Sampling fee: $120 private label, $300 build on an existing formula, $500 full custom.
Lower-commitment option: sachet sampling and kit assembly in 1 to 10 mL formats.
See how a full program runs on our private label service page.
Certifications and regulatory pathways behind an acid product
Hong Shin operates under ISO 22716 cosmetic GMP and ISO 9001, with SEDEX and BSCI for ethical and social compliance, and a US FDA-registered facility. The FDA does not approve cosmetics, so the accurate claim is an FDA-registered facility, not an FDA-approved product.
Regulatory support covers the pathways a multi-market acid launch typically needs:
Health Canada NPN and cosmetic notification (see our Health Canada cosmetic notification guide)
US FDA OTC and 25(b) exempt filing experience (plus our MoCRA explainer for US brand obligations)
EU CPNP and UKCA
Match the pathway to your markets before sampling, because acid limits and sun-sensitivity wording differ by region.
Frequently asked questions
Glycolic vs salicylic acid: which is better?
Neither, in general. Glycolic is a small, water-soluble AHA aimed at surface texture and dullness. Salicylic is an oil-soluble BHA aimed at oil and congestion. The better choice is the one that matches your customer and your markets.
Can you use glycolic and salicylic acid together?
In a routine, many lines sell both for different concerns. In one formula, two acids change the pH and total acid load, so a blend is designed as a whole and tested in sampling.
Is mandelic acid an AHA or a BHA?
Mandelic acid is an AHA. It is a larger molecule than glycolic (152 vs 76 g/mol) and more lipophilic than glycolic, but it is not oil-soluble the way salicylic acid is.
Is salicylic acid a cosmetic or an OTC drug?
It depends on the claims. In the US, salicylic acid at 0.5 to 2% is an acne active under 21 CFR 333.310, so a product that claims to treat acne is an OTC drug. Cosmetic wording such as "clearer-looking skin" stays cosmetic, subject to review.
What is the minimum order for an acid product with Hong Shin?
The first run is 1,500 units per SKU on the Taiwan route and 3,000 units per SKU on the South Korea route, which handles SPF serums and cream serums. The quote comes back within 5 business days of the brief. Sampling is $120 private label, $300 build on an existing formula or $500 full custom.
Work with Hong Shin
The glycolic vs salicylic vs mandelic decision is really a decision about who you sell to, and the right answer is often one acid built well rather than three at once. Send us your target audience, target markets and rough volumes, and we will spec a compliant acid formula and return a quote within 5 business days. Start with our private label service, or request a quote.