Skip to content
Free shipping for orders $60+
Your cart is currently empty.

The Science and Benefits of Propanediol in Skincare: Humectant, Moisturizer, Barrier Enhancer, and Antimicrobial Agent - Forms, Safety, Formulation, and Research

Last updated: Aug 2023
In this article:

Introduction to Propanediol in Skincare

Propanediol, also known as Propylene Glycol, is a versatile ingredient that is frequently utilized in skincare products. It not only serves as a humectant, attracting moisture to the skin, but it also possesses other beneficial properties that make it a popular choice among skincare enthusiasts. This guide will provide you with a comprehensive overview of the uses and benefits of propanediol in skincare.

Humectant Properties

One of the primary roles of propanediol in skincare products is to act as a humectant. It has the ability to draw moisture from the environment, retaining it in the skin. This helps to keep the skin hydrated and prevents dryness, which can lead to various skin issues. Propanediol-based products effectively moisturize the skin, leaving it soft, supple, and free from uncomfortable tightness.

Enhances Product Absorption

Propanediol acts as a penetration enhancer, facilitating the absorption of other active ingredients in skincare products. By improving their delivery into the deeper layers of the skin, propanediol ensures that these ingredients can exert their maximum effects. This ultimately enhances the efficacy of skincare products, allowing you to experience noticeable improvements in your skin's texture and appearance.

Soothing and Calming Effect

Propanediol possesses soothing and calming properties, making it an excellent choice for those with sensitive or irritated skin. It helps to reduce inflammation and redness, providing relief to irritated skin. If you experience sensitivity or have skin conditions such as eczema or rosacea, propanediol-based products can help alleviate discomfort and promote a healthier complexion.

Preservative Function

In addition to its humectant and soothing properties, propanediol also acts as a preservative in skincare formulations. It helps to prevent the growth of bacteria and molds, extending the shelf life of products and ensuring their safety for use. This is crucial in skincare products, as it allows you to enjoy their benefits for a longer period without compromising their efficacy.

Benefits of Propanediol for Skincare

Propanediol, a popular ingredient in skincare products, offers numerous benefits for the skin. Whether you struggle with dryness, dullness, or skin sensitivity, incorporating products containing propanediol into your skincare routine can help improve your complexion and enhance overall skin health. In this guide, we will explore the four main benefits of propanediol for skincare.

1. Humectant Properties

One of the primary benefits of propanediol is its excellent humectant properties. Humectants are substances that help attract and retain moisture in the skin, preventing dehydration. Propanediol acts as an effective humectant by drawing water molecules from the air and binding them to the skin, keeping it hydrated and supple. Regular use of propanediol-infused skincare products can help combat dryness and flakiness, ensuring your skin remains moisturized throughout the day.

2. Enhanced Moisturization

Propanediol not only helps retain moisture but also aids in the penetration of other skincare ingredients. Its unique ability to enhance the absorption and efficacy of other active ingredients allows for better moisturization. When combined with hydrating compounds like hyaluronic acid or glycerin, propanediol works synergistically to deliver deep hydration to the skin, resulting in a soft, plump, and refreshed appearance.

3. Improvement of Skin Barrier Function

The skin barrier, also known as the stratum corneum, plays a vital role in protecting the skin from environmental stressors and maintaining moisture balance. Propanediol has been shown to strengthen the skin barrier by enhancing the synthesis of ceramides, natural lipids that help seal in moisture and maintain skin integrity. By fortifying the skin barrier, propanediol helps to prevent water loss, reduce sensitivity, and increase the skin's resilience to external irritants.

4. Antimicrobial Effects

Propanediol exhibits antimicrobial properties, making it an ideal ingredient for individuals with acne-prone or sensitive skin. It helps inhibit the growth of certain bacteria and fungi that can contribute to breakouts, redness, and inflammation. By incorporating propanediol into your skincare routine, you can promote a healthier, clearer complexion while also reducing the risk of skin infections.

Different Forms of Propanediol in Skincare Products

Propylene glycol is a common form of propanediol found in skincare products. It is a clear, odorless liquid with excellent moisturizing properties. It attracts water from the air and locks it into the skin, keeping it hydrated and supple.

  • Moisturizing benefits
  • Acts as a penetration enhancer
  • Excellent ingredient in serums, moisturizers, and creams

Propylene Glycol

Propylene glycol is a common form of propanediol found in skincare products. It is a clear, odorless liquid that has excellent moisturizing properties. It works by attracting water from the air and locking it into the skin, keeping it hydrated and supple.

  • Works as a moisturizer
  • Acts as a penetration enhancer

Dipropylene Glycol

Dipropylene glycol is another form of propanediol commonly used in skincare products. It is a thicker, viscous liquid compared to propylene glycol. It has excellent moisturizing properties and acts as a penetration enhancer.

  • Used in emollient skincare products like lotions and body creams
  • Provides a luxurious and rich texture

Other Derivatives

Apart from propylene glycol and dipropylene glycol, other derivatives of propanediol are used in skincare products. These derivatives have similar properties but may offer additional benefits depending on their formulation.

  • Butylene glycol: acts as a humectant and has antioxidant properties
  • Tripropylene glycol: thicker liquid used in heavier skincare products

Safety and Potential Side Effects of Propanediol

Propanediol is a commonly used chemical compound with a wide range of applications, including use in cosmetics, personal care products, and pharmaceuticals. While generally considered safe for use, it's important to be aware of potential side effects and safety concerns associated with this compound. This guide aims to provide information on three main topics: potential irritation or sensitivity, allergenicity, and toxicity and environmental impact.

Potential Irritation or Sensitivity

Propanediol has been reported to cause mild irritation in some individuals, particularly those with sensitive skin. Signs of irritation may include redness, itching, or a burning sensation. To minimize the risk of irritation, individuals with sensitive skin should consider patch testing a product containing propanediol before applying it to a larger area of the body. If any irritation occurs, it is advisable to discontinue use and consult a dermatologist for further guidance.


While propanediol itself is not considered to be a common allergen, it is important to note that there is a possibility of allergic reactions in some individuals. Allergic reactions can manifest as skin rashes, hives, or even respiratory symptoms in severe cases. If you have a known sensitivity to other glycols or have experienced allergic reactions to similar compounds, it is advisable to exercise caution and consult with a healthcare professional before using products containing propanediol.

Toxicity and Environmental Impact

Propanediol is generally recognized as safe for use in cosmetics and personal care products. It has a low level of oral and dermal toxicity when used at recommended concentrations. However, in rare cases of excessive ingestion or exposure, it may cause gastrointestinal upset or skin irritation. It is important to follow prescribed usage guidelines and avoid excessive or prolonged exposure to minimize the risk of adverse effects.

In terms of environmental impact, propanediol is considered to be a relatively eco-friendly alternative compared to other glycols. It is biodegradable and does not persist in the environment. However, it is still important to dispose of products containing propanediol properly and avoid excessive use to reduce potential accumulation in the ecosystem.

Recommended Concentrations

  • Follow recommended concentrations of active ingredients
  • High concentration can cause skin irritation
  • Low concentration may not deliver desired benefits
  • Pay attention to usage levels provided by suppliers

Synergistic Ingredient Combinations

  • Some ingredients work better together
  • Identify synergies to enhance efficacy
  • For example, combining antioxidants like vitamin C and E

Use in Different Skincare Products

  • Consider formulation type (creams, lotions, serums, gels)
  • Oil-soluble ingredients perform better in creams and lotions
  • Water-soluble ingredients are suitable for serums and gels
  • Understand compatibility with different product bases

Stability and Shelf Life

  • Ensure formulations maintain effectiveness over time
  • Choose stable ingredients for the formulation and packaging
  • Antioxidants help extend shelf life by preventing oxidation
  • Regular stability testing ensures quality and safety

Studies and Research on Propanediol for Skincare

Propanediol is a versatile ingredient that has gained attention in the skincare industry for its various benefits. Extensive studies and research have been conducted to understand its efficacy in hydration and moisturization, its effectiveness in enhancing the penetration of other actives, and how it compares with other humectants and moisturizers. Let's delve deeper into each of these topics.

Efficacy in Hydration and Moisturization

Numerous studies have shown that propanediol is a highly effective humectant, meaning it attracts and retains moisture in the skin. It has been found to improve skin hydration levels and reduce transepidermal water loss, ultimately leading to improved skin barrier function and overall moisturization. Its ability to enhance the water-holding capacity of the skin makes it especially beneficial for individuals with dry or dehydrated skin.

Effectiveness in Enhancing Penetration of Other Actives

Propanediol has been found to enhance the penetration of other active ingredients into the skin. Research suggests that it aids in the delivery of beneficial compounds deeper into the skin layers, thus maximizing their effectiveness. This makes propanediol a valuable addition to skincare formulations that aim to improve the delivery and efficacy of other actives, such as antioxidants, vitamins, and peptides.

Comparison with Other Humectants and Moisturizers

Studies have compared the efficacy of propanediol with other commonly used humectants and moisturizers, such as glycerin and sorbitol. The results have shown that propanediol performs on par or even better in terms of hydrating and moisturizing the skin. Additionally, unlike some other humectants, propanediol has been found to have a non-sticky, lightweight texture, making it more pleasant to use in skincare products.


  1. Propanediol is a multifunctional ingredient commonly used in skincare products due to its ability to act as a solvent, humectant, and viscosity regulator.

  2. It helps to enhance the absorption and delivery of active ingredients, promoting better penetration into the skin for improved efficacy of other skincare products.

  3. Propanediol has humectant properties, meaning it attracts and retains moisture from the environment, helping to keep the skin hydrated and prevent dryness.

  4. It has a lightweight, non-greasy texture, making it suitable for various skin types, including oily and sensitive skin.

  5. Propanediol has a low potential for skin irritation and is considered to be safer and less sensitizing compared to other glycols commonly used in skincare formulations.

  6. It can also contribute to the overall sensory experience of skincare products, providing a smooth and silky texture while improving the spreadability and absorption on the skin.