Polyhydroxystearic Acid: What Is It, Cosmetic Uses & Side Effects

This article was last updated on: November 25, 2023

Navigating the world of cosmetics often feels like deciphering a scientific lexicon. Labels are adorned with complex names that can perplex even the most enthusiastic beauty aficionados. Amidst these myriad ingredients, one name that might catch your eye is Polyhydroxystearic Acid. This ingredient, with its notably scientific and somewhat intimidating nomenclature, is more common in cosmetic products than one might initially assume.

In this article, we’ll unravel the mysteries surrounding this obscure-sounding ingredient, offering a comprehensive guide to everything you need to know about Polyhydroxystearic Acid. From its basic properties to its role in cosmetics, we’ll explore this component in detail, demystifying its presence in your favorite beauty products!

What is Polyhydroxystearic Acid?

In the realm of cosmetics, Polyhydroxystearic Acid stands out as a multifunctional ingredient, known alternatively as 12-Hydroxyoctadecanoic acid, homopolymer. Its primary role in cosmetic products is as an emulsifying agent, which means it helps to blend water with oils and fats, creating a stable and uniform mixture. This ability is crucial in products like creams and lotions, ensuring they maintain a consistent texture and efficacy.

Polyhydroxystearic Acid typically appears in concentrations ranging from 0.1% to 5% in cosmetic formulations – its effectiveness at these levels makes it a popular choice for achieving the desired product consistency and performance. Rarely sold as a stand-alone product, Polyhydroxystearic Acid is more commonly found as a component within a broader formulation, contributing to the overall stability and texture of the cosmetic product.

Who Can Use Polyhydroxystearic Acid?

Polyhydroxystearic Acid is a versatile ingredient suitable for a variety of skin types. Its non-irritating nature makes it a fitting choice for both sensitive and non-sensitive skin, ensuring broad usability across different consumer demographics. This adaptability is one of the reasons why it’s a preferred ingredient in many cosmetic formulations.

Regarding dietary preferences, Polyhydroxystearic Acid is typically suitable for vegans and vegetarians, being typically synthesized through a chemical process using plant-derived stearic acid or other vegetable sources. It does not involve animal derivatives or by-products. However, as with any cosmetic ingredient, it’s advisable for consumers to check the source if they adhere to strict vegan or vegetarian guidelines.

For pregnant or breastfeeding women, there is no specific contraindication against using products containing Polyhydroxystearic Acid. Nevertheless, it’s always recommended that expecting or nursing mothers consult with their healthcare provider before adding new products to their skincare routine, to ensure safety for both mother and child.

Polyhydroxystearic Acid’s Cosmetic Uses

Polyhydroxystearic Acid is classified as a non-active ingredient in cosmetics. This means that it does not directly contribute to the primary performance or therapeutic effect of the product. Instead, non-active ingredients support the formulation by enhancing texture, stability, or application properties, ensuring that the active ingredients can perform effectively.

The uses of Polyhydroxystearic Acid, based on its official function as an emulsifying agent, include:

  • Enhancing Product Stability: By effectively blending oil and water components, Polyhydroxystearic Acid helps maintain the consistency and homogeneity of cosmetic products. This stabilization is crucial for ensuring that the product doesn’t separate over time, thereby maintaining its intended efficacy from the first to the last use.
  • Improving Texture and Feel: In creams and lotions, Polyhydroxystearic Acid contributes to a smoother, more luxurious texture. This improved tactile experience makes the product more appealing and satisfying to use, as it glides effortlessly across the skin.
  • Facilitating Even Dispersion of Ingredients: This ingredient aids in the even distribution of various components within a formulation. Whether it’s pigments in a foundation or active ingredients in a skincare product, Polyhydroxystearic Acid ensures that each application delivers a uniform effect, enhancing the overall performance of the product.
  • Increasing Product Efficacy: By ensuring that oil-based and water-based ingredients are thoroughly mixed, Polyhydroxystearic Acid helps in creating an effective delivery system for the active ingredients. This harmonious blend ensures that the actives are evenly dispersed and can be absorbed efficiently by the skin.
  • Enhancing Product Application: The smooth consistency afforded by Polyhydroxystearic Acid makes the application of cosmetics more seamless. This is particularly important in makeup products, where even, streak-free application is essential for a flawless finish.

Each of these benefits stems from Polyhydroxystearic Acid’s ability to emulsify and stabilize cosmetic formulations, showcasing its integral role in enhancing the overall quality and performance of cosmetic products.

Polyhydroxystearic Acid Potential Side Effects

The side effects and reactions to Polyhydroxystearic Acid can vary widely from person to person, primarily due to individual differences in skin type. Factors like skin sensitivity, underlying skin conditions, and even genetic predispositions can influence how one’s skin reacts to certain ingredients.

While Polyhydroxystearic Acid is generally considered safe for use in cosmetic products, some potential side effects include:

  • Skin Irritation: In rare cases, this ingredient may cause redness or irritation, particularly in individuals with extremely sensitive skin.
  • Allergic Reactions: Although uncommon, some people might experience allergic reactions, manifesting as itching, rash, or swelling.
  • Comedogenic Effects: For some skin types, particularly those prone to acne, Polyhydroxystearic Acid might contribute to clogged pores and breakouts.

If you experience any of these side effects while using a product containing Polyhydroxystearic Acid, it’s advisable to discontinue use immediately and consult a dermatologist if symptoms persist or worsen. In most cases, simply stopping the use of the offending product will alleviate the symptoms.

It’s important to note that adverse reactions to Polyhydroxystearic Acid are rare. This ingredient is generally recognized for its safety and effectiveness in cosmetic formulations. However, as with any cosmetic ingredient, individual responses can vary.

To minimize the risk of adverse reactions, it’s crucial to conduct a patch test before introducing a new product into your skincare routine. Our patch testing guide provides a step-by-step approach to safely testing products, ensuring they are compatible with your skin and reducing the likelihood of unexpected reactions. This simple precautionary step can help identify potential sensitivities and ensure a positive experience with new cosmetic products.

Comedogenic Rating

Polyhydroxystearic Acid holds a comedogenic rating of 1 on a scale of 0 to 5, where 0 signifies non-comedogenic and 5 indicates a high likelihood of clogging pores.

This relatively low rating stems from its molecular structure and formulation use, which are typically not prone to causing pore blockage. However, it’s important to acknowledge that individual skin responses can vary, and what is minimally comedogenic for one person may not be the same for another.

Given its low comedogenic rating, Polyhydroxystearic Acid is generally suitable for individuals prone to acne and breakouts.


Not every ingredient in personal care products, such as skincare, is meant to have an immediate, transformative impact. Some, like Polyhydroxystearic Acid, are there to support the overall formulation, classifying them as non-active ingredients. These components are essential for enhancing the stability, texture, and efficacy of the product, ensuring that the active ingredients can do their job effectively.

Polyhydroxystearic Acid is valued for its ability to improve product consistency, stability, and application. It’s a testament to the saying that sometimes the supporting roles are just as crucial as the leads.

In terms of popularity, Polyhydroxystearic Acid is not a standout star in cosmetic formulations but plays a vital, albeit understated, role. It’s a common ingredient, similar to other emulsifiers like Stearic Acid or Cetyl Alcohol, known for their stabilizing properties in cosmetic formulations.

For those concerned about incorporating Polyhydroxystearic Acid into their skincare routine, it’s reassuring to know that it’s generally well-tolerated, with a low risk of adverse reactions. Its presence in a product signifies a focus on creating a harmonious and stable formulation, contributing to the overall quality and experience of using the product. While it may not be the ingredient that immediately catches your eye on a label, its role in the efficacy and feel of your favorite cosmetics is undeniably significant.

Tell us how you found this article in just a couple of clicks!
Delivered right to your inbox each week. Zero spam, all goodness, opt-out at anytime.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
How did you find this article?
Tell us how you found this article in just a couple of clicks!
Get all our top headlines in beauty.
Delivered right to your inbox each week. Zero spam, all goodness, opt-out at anytime.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Send good feedback:

All feedback is anonymous and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Send bad feedback:

All feedback is anonymous and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.