Our Science
Acids that stay acids.
Most acid skincare lets its acids turn into salts. Neutralyze is formulated at a low pH, so our acids stay in their active free-acid form, the form that actually exfoliates. Here is the chemistry, the ingredients and the formulator behind it.
Why pH matters
The same acid, two very different forms
Every exfoliating acid exists in two forms in a formula. The free acid (for example, salicylic acid) is uncharged and can move into the outer layer of skin to loosen dead cells. The salt (sodium salicylate, sodium mandelate, sodium glycolate) is the ionized form. It carries a charge, so it penetrates skin poorly and does little exfoliating.
Which form wins depends on pH. Each acid has a fixed number called its pKa: at a pH equal to the pKa, exactly half the acid is free acid and half is salt. Every full pH unit above the pKa cuts the free-acid share by roughly ten times. This is the Henderson–Hasselbalch relationship, and it is why two products listing "2% salicylic acid" can behave very differently on skin.
| Share present as free acid | pH 3.5 | pH 4.5 | pH 5.5 |
|---|---|---|---|
| Salicylic acid (pKa 2.97) | 23% | 2.9% | 0.3% |
| Mandelic acid (pKa 3.41) | 45% | 7.5% | 0.8% |
| Glycolic acid (pKa 3.83) | 68% | 18% | 2.1% |
Example pH values for illustration. Values are calculated, not measurements of any specific product.
What the research says
Dermatology reviews describe the free-acid fraction as the part of an AHA that is available to penetrate the stratum corneum and drive exfoliation. Lowering pH toward or below the pKa raises that fraction; raising pH lowers it.[1][2]
Why many products drift higher
Many products are partially neutralized to a higher pH, which converts much of the acid into its salt.[3] Researchers have noted that once product pH reaches about 4 or above, much of an AHA's exfoliating efficacy can be lost.[3] Neutralyze takes the other approach: formulate at a low pH and keep the acids active.
Technology 01
DuoClear™
2% salicylic acid + 1% mandelic acid, formulated at a low pH. Two acids with different jobs, both kept in their active free-acid form instead of sodium salicylate and sodium mandelate.
Salicylic acid works in the pore
Salicylic acid is oil-soluble, so it can move through sebum and into the pore lining to loosen built-up oil and dead skin.
Mandelic acid works on the surface
Mandelic acid is a larger alpha hydroxy acid, so it exfoliates the surface more gradually for smoother, more even-looking skin.
Exfoliating PadsFace WashRenewal Complex
Technology 02
GlycoForte™
20% glycolic acid + hyaluronic acid, formulated at a low pH. Many glycolic products sit at higher pH, where much of the acid becomes sodium glycolate. GlycoForte keeps glycolic acid in its free-acid form for resurfacing, with hyaluronic acid for hydration.
Resurfacing Pads · coming soon
Ingredient guide
Four ingredients, four jobs
Salicylic acid
BHA · C7H6O3 · 138 g/mol · pKa 2.97 · log P 2.26
The most oil-soluble of the group, so it reaches into oily pores. It suits the Face Wash, Pads and Renewal Complex, which are built for pores and texture.
Mandelic acid
AHA · C8H8O3 · 152 g/mol · pKa 3.41 · log P 0.62
The largest common AHA. Its bigger molecule exfoliates more gradually, which makes it a good daily partner to salicylic acid in DuoClear.
Glycolic acid
AHA · C2H4O3 · 76 g/mol · pKa 3.83 · log P −1.11
The smallest AHA and water-soluble, so it works on the skin's surface for resurfacing and smoother texture. That is why it leads GlycoForte in the Resurfacing Pads.
Hyaluronic acid
Humectant · large polysaccharide
Not an exfoliant. A large water-binding molecule that holds moisture at the skin surface, paired with glycolic acid in GlycoForte for hydration.
Molecular weight, pKa and log P (octanol–water partition; higher means more oil-soluble) from PubChem.[4][5][6]
The formulator
George Deckner
Every Neutralyze formula is developed by George Deckner, one of the industry's most prolific skincare formulators.
40+ years, 200+ U.S. patents
George spent 26 years at Procter & Gamble, where he was a Victor Mills Research Fellow and one of the company's top inventors, with 354 granted and filed global patents, including 201 U.S. patents. He helped develop skincare platform technologies used in Olay, Clearasil, Noxzema, Bain de Soleil and SK-II. He retired from P&G in 2013 and now consults for the personal care industry.[7][8][9]
He also writes about formulation for UL Prospector's Knowledge Center, a trade publication for cosmetic chemists.[8]
Selected U.S. patents
- US 5,824,666: Low-pH, hydrolytically stable cosmetic compositions containing acidic actives such as salicylic acid
- US 5,948,416: Stable topical compositions for delivering actives such as salicylic acid
- US 6,537,537: Water-in-silicone emulsions with salicylic acid
- US 6,492,326: Skin care compositions combining skincare actives
- US 4,919,934: Cosmetic sticks
References
Sources
- Formulating Glycolic Acid: Balancing Penetration, Irritation, and Therapeutic Outcomes in Dermatology. Cosmetics 13(4):164 (MDPI). mdpi.com/2079-9284/13/4/164
- Scientific Committee on Cosmetic Products and Non-Food Products (SCCNFP), European Commission. Opinion on alpha hydroxy acids in cosmetic products. ec.europa.eu (PDF)
- Glycolic acid adjusted to pH 4 stimulates collagen production and epidermal renewal without affecting levels of proinflammatory TNF-alpha in human skin explants. Journal of Cosmetic Dermatology (2020). doi.org/10.1111/jocd.13570
- PubChem: Salicylic acid. pubchem.ncbi.nlm.nih.gov
- PubChem: Mandelic acid. pubchem.ncbi.nlm.nih.gov
- PubChem: Glycolic acid. pubchem.ncbi.nlm.nih.gov
- Deckner Innovation & Consulting. decknerconsulting.com
- George Deckner, author profile, UL Prospector Knowledge Center. ulprospector.ul.com
- Chemspire Ingredients, Partners: George Deckner. chemspireingredients.com/partners
- Patents: Google Patents, inventor George Endel Deckner (links above).