Sodium PCA

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 sodium PCA. 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: Sodium PCA is the sodium salt of pyrrolidone carboxylic acid, a humectant the skin makes naturally as part of its natural moisturizing factor (NMF). In ORY^® products, it helps skin and hair hold moisture with a light, non-sticky feel.

Verification: Supported. The Cosmetic Ingredient Review (CIR) Expert Panel found PCA and its salts, including sodium PCA, safe as used in cosmetics, but said they should not be used in products where N-nitroso compounds can form.

Citations:

- Fiume, M. M., et al. (2019). Amended safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and its salts as used in cosmetics. International Journal of Toxicology. https://doi.org/10.1177/1091581819856568
  - What it shows: CIR amended safety assessment.
- Andersen, F. A. (Ed.). (1999). Final report on the safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and sodium PCA. International Journal of Toxicology, 18(Suppl 2), 25–34. https://doi.org/10.1177/109158189901800206
  - What it shows: Original CIR assessment.

2. Composition and Production

Claim: Sodium PCA is made by converting plant-derived glutamic acid into pyroglutamic acid and neutralizing it. It is supplied as a 50% solution.

Verification: Supported. In the skin, PCA is formed from the breakdown of the protein filaggrin and is one of the largest components of NMF.

Citations:

- Rawlings, A. V., & Harding, C. R. (2004). Moisturization and skin barrier function. Dermatologic Therapy, 17(Suppl 1), 43–48. https://doi.org/10.1111/j.1396-0296.2004.04s1005.x
  - What it shows: Review of NMF composition.
- Verdier-Sévrain, S., & Bonté, F. (2007). Skin hydration: A review on its molecular mechanisms. Journal of Cosmetic Dermatology, 6(2), 75–82. https://doi.org/10.1111/j.1473-2165.2007.00300.x
  - What it shows: Review of skin hydration.

3. Skin Type Suitability

Claim: Sodium PCA suits all skin types.

Verification: Supported. CIR found it safe as used.

Citations:

- Fiume, M. M., et al. (2019). Amended safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and its salts as used in cosmetics. International Journal of Toxicology. https://doi.org/10.1177/1091581819856568
  - What it shows: Safety data.

4. Hair and Scalp Suitability

Claim: In haircare, sodium PCA helps hair feel moisturized and more manageable.

Verification: Limited evidence. We found no clinical studies of sodium PCA on hair. ORY^® haircare products are not intended to treat scalp conditions.

Citations:

- Verdier-Sévrain, S., & Bonté, F. (2007). Skin hydration: A review on its molecular mechanisms. Journal of Cosmetic Dermatology, 6(2), 75–82. https://doi.org/10.1111/j.1473-2165.2007.00300.x
  - What it shows: General review.

5. Benefits

Claim: Sodium PCA helps skin feel hydrated, smooth, and soft.

Verification: Supported, with caveats. Reviews describe NMF components such as PCA as key to skin hydration. We found no controlled clinical trials of sodium PCA alone in cosmetics.

Citations:

- Rawlings, A. V., & Harding, C. R. (2004). Moisturization and skin barrier function. Dermatologic Therapy, 17(Suppl 1), 43–48. https://doi.org/10.1111/j.1396-0296.2004.04s1005.x
  - What it shows: NMF review.
- Verdier-Sévrain, S., & Bonté, F. (2007). Skin hydration: A review on its molecular mechanisms. Journal of Cosmetic Dermatology, 6(2), 75–82. https://doi.org/10.1111/j.1473-2165.2007.00300.x
  - What it shows: Hydration review.

6. Use Across ORY^® Product Lines

Claim: Sodium PCA is used in ORY^® Skincare, Haircare, and Cosmetics, and in liquid and syndet cleansers.

Verification: Supported. ORY^® does not combine sodium PCA with ingredients that can form nitrosamines, following CIR’s caution. It rinses away in bar soap, so it is used only in liquid and syndet cleansers in that line.

Product line	Typical level	How ORY^® uses it
Skincare	0.5–3%	Serums, toners, essences, creams, lotions, masks, and cleansers.
Haircare	0.5–2%	Leave-ins, conditioners, scalp serums, and shampoos.
Handmade Soap line	0.5–1% in liquid/syndet	Liquid soaps and syndet bars only.
Cosmetics	0.5–2%	Foundations, primers, setting sprays, and lip products.

Citations:

- Fiume, M. M., et al. (2019). Amended safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and its salts as used in cosmetics. International Journal of Toxicology. https://doi.org/10.1177/1091581819856568
  - What it shows: CIR conclusion and caution.
- 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: A skin-identical, light-feeling humectant with a CIR safety conclusion.

Verification: Supported. Well documented.

Citations:

- Fiume, M. M., et al. (2019). Amended safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and its salts as used in cosmetics. International Journal of Toxicology. https://doi.org/10.1177/1091581819856568
  - What it shows: Safety conclusion.

8. Cons

Claim: Sodium PCA costs more than glycerin, needs a moisturizer in dry air, and must be kept away from nitrosating ingredients.

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

- Cost. Higher than glycerin.
- Dry air. Pair with an emollient.
- Formulation caution. Not combined with nitrosating agents.
- Limited clinical data. Evidence is mostly from NMF research.

Citations:

- Fiume, M. M., et al. (2019). Amended safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and its salts as used in cosmetics. International Journal of Toxicology. https://doi.org/10.1177/1091581819856568
  - What it shows: Caution.

9. Safety Notes

Claim: Patch test before use; for external use only.

Verification: Supported. Follow these precautions:

- Patch test any new product on a small area for 24–48 hours before full use.
- Humectants work best when followed by a moisturizer or oil, especially in dry air.
- Stop use if redness, burning, itching, or rash occurs, and talk to a healthcare provider.
- For external use only. Avoid the eyes. Do not use on broken or seriously damaged skin.
- If you are pregnant, nursing, have a medical condition, or are buying for a child, ask a healthcare provider before use.

Citations:

- Fiume, M. M., et al. (2019). Amended safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and its salts as used in cosmetics. International Journal of Toxicology. https://doi.org/10.1177/1091581819856568
  - What it shows: Safety conclusion.

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

- Andersen, F. A. (Ed.). (1999). Final report on the safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and sodium PCA. International Journal of Toxicology, 18(Suppl 2), 25–34. https://doi.org/10.1177/109158189901800206
- Fiume, M. M., et al. (2019). Amended safety assessment of PCA (2-pyrrolidone-5-carboxylic acid) and its salts as used in cosmetics. International Journal of Toxicology. https://doi.org/10.1177/1091581819856568
- Rawlings, A. V., & Harding, C. R. (2004). Moisturization and skin barrier function. Dermatologic Therapy, 17(Suppl 1), 43–48. https://doi.org/10.1111/j.1396-0296.2004.04s1005.x
- Verdier-Sévrain, S., & Bonté, F. (2007). Skin hydration: A review on its molecular mechanisms. Journal of Cosmetic Dermatology, 6(2), 75–82. https://doi.org/10.1111/j.1473-2165.2007.00300.x

Government and regulatory sources

- 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

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Sodium PCA

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