Lactic Acid

At ORY^®, we believe you should know what’s in your products and why. This page lists the published research behind what we say about lactic acid. Each section starts with our claim, then tells you how well the research supports it, then lists the sources so you can read them yourself.

How to read this page

Supported — backed by peer-reviewed research or official safety reviews.

Supported, with caveats — the research points this way, but mostly from laboratory or animal studies, or at different strengths than ORY^® uses.

Limited evidence — little or no published research yet. We say so openly.

1. General Description and Role

Claim: Lactic acid is a gentle alpha hydroxy acid (AHA) made by fermenting sugars. It is also part of the skin’s own natural moisturizing factor, so it hydrates at low levels and exfoliates at higher levels. Its larger molecule works more gradually than glycolic acid, which makes it a good AHA for sensitive and dry skin.

Verification: Supported. Lactic acid’s dual role as a moisturizer and exfoliant is well documented. The Cosmetic Ingredient Review (CIR) Expert Panel found it safe in consumer products at 10% or less with a final pH of 3.5 or higher, when formulated to avoid increasing sun sensitivity or when directions include daily sun protection.

Citations:

- Algiert-Zielińska, B., Mucha, P., & Rotsztejn, H. (2019). Lactic and lactobionic acids as typically moisturizing compounds. International Journal of Dermatology, 58(3), 374–379. https://doi.org/10.1111/ijd.14202
  - What it shows: Review of lactic acid as a moisturizing ingredient and part of the skin’s natural moisturizing factor.
- Andersen, F. A. (Ed.). (1998). Final report on the safety assessment of glycolic acid, ammonium, calcium, potassium, and sodium glycolates, methyl, ethyl, propyl, and butyl glycolates, and lactic acid, ammonium, calcium, potassium, sodium, and TEA-lactates, methyl, ethyl, isopropyl, and butyl lactates, and lauryl, myristyl, and cetyl lactates. International Journal of Toxicology, 17(Suppl 1), 1–241. https://doi.org/10.1177/109158189801700101
  - What it shows: CIR safety review setting the 10% / pH 3.5 limits for consumer products.
- Tang, S. C., & Yang, J. H. (2018). Dual effects of alpha-hydroxy acids on the skin. Molecules, 23(4), 863. https://pubmed.ncbi.nlm.nih.gov/29642579/
  - What it shows: Review of AHA mechanisms and effects.

2. Composition and Production

Claim: Lactic acid (C₃H₆O₃) is made commercially by fermenting sugar from corn, beet, or cane. ORY^® uses L-lactic acid, the same form found in skin. Neutralized, it becomes sodium lactate, a humectant in skin care and a hardening agent in soap.

Verification: Supported. Production, isomers, and the sodium lactate salt are well documented. Research also found the L-form was more effective than the D-form at boosting skin ceramides.

Citations:

- Rawlings, A. V., Davies, A., Carlomusto, M., et al. (1996). Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function. Archives of Dermatological Research, 288(7), 383–390. https://doi.org/10.1007/BF02507107
  - What it shows: Compared L- and D-lactic acid; L-lactic acid boosted ceramides and barrier function.
- Algiert-Zielińska, B., Mucha, P., & Rotsztejn, H. (2019). Lactic and lactobionic acids as typically moisturizing compounds. International Journal of Dermatology, 58(3), 374–379. https://doi.org/10.1111/ijd.14202
  - What it shows: Describes lactic acid’s sources and forms.

3. Skin Type Suitability

Claim: Lactic acid suits all seven ORY^® skin types when the strength is matched to the skin. It is especially good for dry and sensitive skin, and it helps mature skin look firmer and smoother.

Verification: Supported. Its gentler action and hydrating properties are documented. People with sensitive skin should start with low strengths.

Citations:

- Algiert-Zielińska, B., Mucha, P., & Rotsztejn, H. (2019). Lactic and lactobionic acids as typically moisturizing compounds. International Journal of Dermatology, 58(3), 374–379. https://doi.org/10.1111/ijd.14202
  - What it shows: Hydrating properties that suit dry skin.
- Smith, W. P. (1996). Epidermal and dermal effects of topical lactic acid. Journal of the American Academy of Dermatology, 35(3 Pt 1), 388–391. https://doi.org/10.1016/S0190-9622(96)90602-7
  - What it shows: Firmness and smoothness results at 12%.

4. Hair and Scalp Suitability

Claim: In haircare, lactic acid adjusts the pH of shampoos and conditioners, gently lifts scalp buildup, and is used in acidic rinses for smoother, shinier-looking hair.

Verification: Limited evidence. Using lactic acid to adjust pH is a standard formulation practice. We found no published clinical studies of lactic acid on the scalp or hair fiber. ORY^® haircare products are not intended to treat dandruff or scalp conditions, or to grow hair or prevent hair loss.

Citations:

- Tang, S. C., & Yang, J. H. (2018). Dual effects of alpha-hydroxy acids on the skin. Molecules, 23(4), 863. https://pubmed.ncbi.nlm.nih.gov/29642579/
  - What it shows: Background on how AHAs act on the skin surface, which is the basis for scalp use.

5. Benefits

Claim: Lactic acid gently exfoliates, hydrates, supports a healthy-looking skin barrier, helps skin look firmer, helps reduce the look of fine lines, and smooths rough, bumpy-feeling skin.

Verification: Supported. In a controlled human study, 12% lactic acid increased the thickness and firmness of the skin and improved smoothness and the look of lines, while 5% improved the outer layer only. Another study found L-lactic acid increased ceramide production and improved barrier function. Note: the 12% study strength is above the CIR’s 10% limit for consumer products.

Citations:

- Smith, W. P. (1996). Epidermal and dermal effects of topical lactic acid. Journal of the American Academy of Dermatology, 35(3 Pt 1), 388–391. https://doi.org/10.1016/S0190-9622(96)90602-7
  - What it shows: Human study of 5% and 12% lactic acid.
- Rawlings, A. V., Davies, A., Carlomusto, M., et al. (1996). Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function. Archives of Dermatological Research, 288(7), 383–390. https://doi.org/10.1007/BF02507107
  - What it shows: Ceramide and barrier findings.
- Algiert-Zielińska, B., Mucha, P., & Rotsztejn, H. (2019). Lactic and lactobionic acids as typically moisturizing compounds. International Journal of Dermatology, 58(3), 374–379. https://doi.org/10.1111/ijd.14202
  - What it shows: Hydration evidence.

6. Use Across ORY^® Product Lines

Claim: Lactic acid has a role in all four ORY^® product lines. In soap it works as sodium lactate, not as an exfoliant.

Verification: Supported. ORY^® consumer leave-on products follow the CIR limits of 10% or less at pH 3.5 or higher. In soap, lye converts lactic acid to sodium lactate, which hardens the bar; the lye amount must be increased to balance the acid.

Product line	Typical level	How ORY^® uses it
Skincare	Up to 10% (pH 3.5 or higher)	Exfoliating toners, serums, night creams, and body lotions; sodium lactate as a humectant.
Haircare	0.1–1% pH adjustment; 1–5% treatments	Shampoos, conditioners, scalp serums, and acidic rinses.
Handmade Soap	1–3% sodium lactate of oil weight	Added to cooled lye water to form sodium lactate for a harder, longer-lasting bar.
Cosmetics	0.1–3%	pH adjuster and humectant in emulsions, foundations, and lip products.

Citations:

- Andersen, F. A. (Ed.). (1998). Final report on the safety assessment of glycolic acid, ammonium, calcium, potassium, and sodium glycolates, methyl, ethyl, propyl, and butyl glycolates, and lactic acid, ammonium, calcium, potassium, sodium, and TEA-lactates, methyl, ethyl, isopropyl, and butyl lactates, and lauryl, myristyl, and cetyl lactates. International Journal of Toxicology, 17(Suppl 1), 1–241. https://doi.org/10.1177/109158189801700101
  - What it shows: Concentration and pH limits for consumer products.
- U.S. Food and Drug Administration. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?) https://www.fda.gov/cosmetics/cosmetics-laws-regulations/it-cosmetic-drug-or-both-or-it-soap
  - What it shows: FDA explains how soap is regulated.

7. Pros

Claim: Gentle yet effective, hydrates while it exfoliates, supports the skin barrier, useful in every ORY^® line, and affordable.

Verification: Supported. Supported by clinical and review literature.

Citations:

- Smith, W. P. (1996). Epidermal and dermal effects of topical lactic acid. Journal of the American Academy of Dermatology, 35(3 Pt 1), 388–391. https://doi.org/10.1016/S0190-9622(96)90602-7
  - What it shows: Clinical results.
- Rawlings, A. V., Davies, A., Carlomusto, M., et al. (1996). Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function. Archives of Dermatological Research, 288(7), 383–390. https://doi.org/10.1007/BF02507107
  - What it shows: Barrier benefits.

8. Cons

Claim: Lactic acid works more slowly than glycolic acid, increases sun sensitivity, must stay within pH limits, and requires careful lye calculation in soap.

Verification: Supported. We list these limits so you have the full picture:

- Sun sensitivity. Like all AHAs, it can increase sensitivity to the sun. Use sunscreen daily.
- Slower results. Its larger molecule works more gradually than glycolic acid.
- pH limits. Leave-on products must stay at pH 3.5 or higher.
- Stinging. Higher strengths can tingle, especially on compromised skin.
- Soap formulation. Extra lye must be calculated precisely.

Citations:

- U.S. Food and Drug Administration. Alpha Hydroxy Acids (including the 2005 guidance, Labeling for Cosmetics Containing Alpha Hydroxy Acids). https://www.fda.gov/cosmetics/cosmetic-ingredients/alpha-hydroxy-acids
  - What it shows: FDA guidance on AHA sun sensitivity.
- Andersen, F. A. (Ed.). (1998). Final report on the safety assessment of glycolic acid, ammonium, calcium, potassium, and sodium glycolates, methyl, ethyl, propyl, and butyl glycolates, and lactic acid, ammonium, calcium, potassium, sodium, and TEA-lactates, methyl, ethyl, isopropyl, and butyl lactates, and lauryl, myristyl, and cetyl lactates. International Journal of Toxicology, 17(Suppl 1), 1–241. https://doi.org/10.1177/109158189801700101
  - What it shows: Safety limits for concentration and pH.

9. Safety Notes

Claim: Use sunscreen daily and start slowly.

Verification: Supported. Follow these precautions:

- Use a broad-spectrum sunscreen daily while using exfoliating products and for a week afterwards.
- Start two to three times a week and increase as tolerated.
- Patch test any new product on a small area for 24–48 hours before full use.
- Do not use on broken, sunburned, or irritated skin. Avoid the eyes.
- If you are pregnant, nursing, have a medical condition, or are buying for a child, ask a healthcare provider before use.

Citations:

- U.S. Food and Drug Administration. Alpha Hydroxy Acids (including the 2005 guidance, Labeling for Cosmetics Containing Alpha Hydroxy Acids). https://www.fda.gov/cosmetics/cosmetic-ingredients/alpha-hydroxy-acids
  - What it shows: Source of the recommended sun-protection statement.

10. Product-line notes

- ORY^® Skincare: For external use only. Not for deep or puncture wounds, animal bites, or serious burns.
- ORY^® Haircare: Designed for scalp comfort and the look and feel of hair. Not intended to treat dandruff or scalp conditions, or to promote hair growth or prevent hair loss. If you notice sudden shedding or a persistent itchy, flaking scalp, see a dermatologist.
- ORY^® Handmade Soap: Handmade soap is naturally alkaline, and each bar may vary slightly in color, scent, and texture. Not intended to treat eczema or any skin condition.
- ORY^® Cosmetics: Lip products are not intended to treat or protect chapped or cracked lips. Do not share applicators, and replace any product that changes color, smell, or texture.

11. References

Peer-reviewed research

- Algiert-Zielińska, B., Mucha, P., & Rotsztejn, H. (2019). Lactic and lactobionic acids as typically moisturizing compounds. International Journal of Dermatology, 58(3), 374–379. https://doi.org/10.1111/ijd.14202
- Andersen, F. A. (Ed.). (1998). Final report on the safety assessment of glycolic acid, ammonium, calcium, potassium, and sodium glycolates, methyl, ethyl, propyl, and butyl glycolates, and lactic acid, ammonium, calcium, potassium, sodium, and TEA-lactates, methyl, ethyl, isopropyl, and butyl lactates, and lauryl, myristyl, and cetyl lactates. International Journal of Toxicology, 17(Suppl 1), 1–241. https://doi.org/10.1177/109158189801700101
- Rawlings, A. V., Davies, A., Carlomusto, M., et al. (1996). Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function. Archives of Dermatological Research, 288(7), 383–390. https://doi.org/10.1007/BF02507107
- Smith, W. P. (1996). Epidermal and dermal effects of topical lactic acid. Journal of the American Academy of Dermatology, 35(3 Pt 1), 388–391. https://doi.org/10.1016/S0190-9622(96)90602-7
- Tang, S. C., & Yang, J. H. (2018). Dual effects of alpha-hydroxy acids on the skin. Molecules, 23(4), 863. https://pubmed.ncbi.nlm.nih.gov/29642579/

Government and regulatory sources

- U.S. Food and Drug Administration. Alpha Hydroxy Acids (including the 2005 guidance, Labeling for Cosmetics Containing Alpha Hydroxy Acids). https://www.fda.gov/cosmetics/cosmetic-ingredients/alpha-hydroxy-acids
- U.S. Food and Drug Administration. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?) https://www.fda.gov/cosmetics/cosmetics-laws-regulations/it-cosmetic-drug-or-both-or-it-soap

1. General Description and Role

2. Composition and Production

3. Skin Type Suitability

4. Hair and Scalp Suitability

5. Benefits

6. Use Across ORY® Product Lines

7. Pros

8. Cons

9. Safety Notes

10. Product-line notes

11. References

6. Use Across ORY^® Product Lines