PEG-100 Stearate: What Is It, Skin & Hair Benefits & Side Effects

Priya Singh
Fact-Checker: Priya Singh
This article was last updated on: November 5, 2023
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Navigating the labyrinth of personal care product labels can often feel like deciphering an ancient script. For the uninitiated, the list of ingredients on skincare and hair care products might as well be in hieroglyphics. Amid the long, scientific-sounding words that tumble off the tongue with a mix of intrigue and complexity, one might encounter PEG-100 Stearate.

The name alone—PEG-100 Stearate—might evoke images of a sterile laboratory with white-coated scientists, far removed from the lush creams and shampoos it graces!

In this article, we’ll unwrap the layers of PEG-100 Stearate to understand its place within cosmetics – we’ll explore its function, benefits, and potential side effects.

What is PEG-100 Stearate?

PEG-100 Stearate is a mouthful, but it’s more than just a complicated name on your favorite cream or lotion – in cosmetics, this ingredient is known for its emollient, cleansing, and emulsifying properties.

Often lurking in the list of ingredients under other aliases such as Polyethylene Glycol (PEG) Stearate 100, it is a critical component in ensuring that oil and water-based ingredients mix harmoniously.

Its general purpose within products is multifaceted—it hydrates, it binds, and it stabilizes. Acting like a charming host at a cocktail party, PEG-100 Stearate invites oil and water to mingle, preventing them from separating into a layered mess. This surfactant isn’t just about maintaining appearances; it enhances the texture of the product, giving it a consistency that feels luxurious between your fingertips.

In terms of concentration, PEG-100 Stearate is typically not a stand-alone show; rather, it plays its part within a broader ensemble of ingredients. While its exact concentration varies by product, it harmonizes within formulas to optimize skin feel and stability without overpowering the composition.

Who Can Use PEG-100 Stearate?

When it comes to who can invite PEG-100 Stearate into their routine, the guest list is quite inclusive. This ingredient is suitable for a variety of skin types, thanks to its gentle nature and compatibility with other cosmetic constituents. From the driest desert skins to the oiliest, PEG-100 Stearate doesn’t discriminate, helping to maintain the peace between skin and product.

For those who live by the vegan or vegetarian ethos, the origin of PEG-100 Stearate is key. Typically, it is synthesized through processes that do not involve animal-derived ingredients, making it suitable for those following a plant-based lifestyle. However, as formulations vary, it’s always recommended to check with the manufacturer if maintaining a vegan or vegetarian regimen is paramount to you.

Pregnant or breastfeeding mothers often have to navigate the skincare landscape more cautiously. While PEG-100 Stearate is generally considered safe, it’s always prudent to consult with a healthcare provider when introducing a new product into your regimen during this sensitive time.

PEG-100 Stearate Skin Benefits

PEG-100 Stearate might not be the hero that always gets a mention, but its understated role in the skincare world comes with a host of benefits:

  • Improved Moisture Retention: PEG-100 Stearate stands out as a mild humectant, which means it helps maintain the skin’s moisture balance. By drawing moisture from the environment and creating a barrier on the skin’s surface, it minimizes transepidermal water loss (TEWL). This not only helps to keep skin hydrated but also contributes to maintaining a smooth, elastic texture. Hydrated skin is less prone to fine lines and wrinkles and has a radiant, healthy appearance.
  • Gentle Cleansing Action: Leveraging its surfactant capabilities, PEG-100 Stearate helps to emulsify the oils that carry dirt and debris on the skin, making it easier to wash away. This gentle cleansing action means that the skin can be freed from impurities without the harshness associated with stronger detergents, which can strip the skin of its natural oils.

While these benefits are indeed appealing, it’s important to note that the skin’s condition remains dynamic. The beneficial effects of PEG-100 Stearate are not permanent fixtures; they require regular application within your skincare routine to maintain.

PEG-100 Stearate Hair Benefits

PEG-100 Stearate isn’t just beneficial for skin, it also brings many benefits for hair:

  • Improved Hair Texture and Manageability: When incorporated into hair care products, PEG-100 Stearate can significantly improve the texture of hair, making it feel softer and more manageable. It achieves this by helping to combine water and oil-based components into a smooth, even texture that coats hair strands evenly. This uniform distribution of conditioning agents results in hair that’s easier to comb through and style.
  • Enhanced Conditioning Effects: As a derivative of stearic acid, a fatty acid commonly found in conditioners, PEG-100 Stearate helps to soften and smooth the hair’s cuticle—the outermost layer of the hair shaft. By doing so, it effectively helps to condition the hair, leading to a sleeker appearance and a reduction in static and frizz, which are often the bane of hair management.
  • Gentle Cleansing Action for the Scalp and Hair: Leveraging its mild surfactant properties, PEG-100 Stearate helps in gently cleansing the scalp and hair without stripping away natural oils. This is particularly beneficial for preventing the hair from becoming overly dry and brittle, which is essential for maintaining the natural balance of the scalp and hair health.

Like the skin benefits, it’s important to understand that the advantages PEG-100 Stearate offers to hair are not everlasting. Regular application is necessary to maintain the hair’s softness, manageability, and overall health.

PEG-100 Stearate Potential Side Effects

While PEG-100 Stearate is considered safe for use in personal care products, reactions to this ingredient can vary from person to person. This variability is due to individual skin types, genetic factors, and pre-existing conditions, which can influence how one’s skin might react to specific ingredients. Understanding your skin type can be a first step in predicting how you might respond to products containing PEG-100 Stearate.

Potential side effects associated with PEG-100 Stearate, though uncommon, may include:

  • Skin Irritation: Some individuals may experience redness or irritation, especially if they have sensitive skin or are prone to allergic reactions.
  • Allergic Reactions: Although rare, there is a possibility of an allergic response, which could manifest as itching, swelling, or a rash.

If you experience any of these side effects while using an ingredient or product containing PEG-100 Stearate, it’s advisable to discontinue use immediately and consult a dermatologist. They can help determine if the reaction is due to PEG-100 Stearate or another ingredient within the product and guide you on the best course of action.

It’s important to emphasize that adverse reactions to PEG-100 Stearate are uncommon. Generally, this ingredient is considered safe and effective for most people. However, everyone’s skin is unique, and what works for the majority might not work for all.

As with any cosmetic product, the importance of patch testing cannot be overstated. A proper patch test can help minimize the risk of a full-blown skin reaction. For a detailed rundown on how to conduct a patch test, refer to our comprehensive patch testing guide.

Comedogenic Rating

When it comes to PEG-100 Stearate, pinning down an exact comedogenic rating can be a bit of a gray area due to variations in individual skin responses and the formulation of the products in which it’s used. However, broadly speaking, PEG-100 Stearate would typically fall around a 1-2 on the 0-5 comedogenic scale.

This low to moderate rating acknowledges that while it’s unlikely to clog pores for most people, there’s still a slight chance it could contribute to breakouts in those with highly acne-prone skin.


Embarking on a skincare or hair care journey is often less about sticking to the beaten path and more about venturing through trial and error. Success in personal care necessitates an experimental mindset, and once you discover the products that resonate with your skin and hair, consistency becomes the key to maintaining those gains.

PEG-100 Stearate, while not the star of the show, plays an indispensable supporting role in many formulations. Its capacity to enhance texture and stabilize products makes it an unsung hero in the cosmetic ingredient lineup. Though not as talked about as some flashier ingredients, its functional benefits lend it a quiet popularity among formulators and those in the know. It’s a common ingredient, similar in function to other emulsifiers and stabilizers like glyceryl stearate and stearic acid.

The timeframe to witness visible results from products containing PEG-100 Stearate will vary based on several factors, including the specific formulation of the product, the concurrent use of other products, and individual skin and hair types. Generally, consistent use over several weeks is necessary to begin seeing the ingredient’s full benefits.

For anyone concerned about incorporating PEG-100 Stearate into their routine, rest assured that it is widely regarded as safe and effective. Despite its wide usage, always consider how your unique skin or hair responds to new ingredients and maintain a watchful eye on how it complements your personalized care regimen.

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