Introduction

I’ve been using the word ‘filler’ a lot in skincare discussions lately, but what I’m talking about has nothing to do with syringes and everything to do with ingredients. When I look at and consider a skincare ingredient, I classify it as either an active ingredient or a filler ingredient. An active ingredient is one added to perform a specific function that benefits your skin. A filler ingredient, on the other hand, is added to a formula for a reason other than improving the health of your skin- whether that is for scent, color, or texture.

When you read an ingredient list, chances are there are at least a handful of ingredients with long or hard-to-pronounce names that you’re not sure what they do, or even what they are. Most people glaze over these and focus on the buzzworthy ingredients that marketing highlights as key ingredients. Most people assume these other ingredients are harmless or even beneficial to the skin.

Unfortunately, the truth of the matter is that these filler ingredients don’t just fail to help your skin- they actually can irritate it and make it worse in the long run. In this article, I’ll explain everything you need to know about filler ingredients so that you can feel confident in your product choices for the health of your skin.

What Makes an Ingredient a “Filler”?

As i mentioned previously, a filler ingredient by my definition, is one that is in the product to essentially take up space without any real benefit to the skin. filler ingredients contribute nothing to barrier repair, nourishment, or long-term skin health. The most egregious ones are artificial dyes and fragrances. These are included for aesthetic purposes only and are actually detrimental to your skin and your body. Other filler ingredients are those that affect a product's texture or skin feel, such as plasticizers. These serve no purpose for the skin, but they are added to mask the potentially unpleasant feeling that the other ingredients can cause.

Although I am not a fan of ingredients such as synthetic preservatives, which have been shown to affect the skin microbiome, I don't consider them fillers, since they are necessary for preventing bacterial growth in certain products. Any ingredient that contains water needs them. That's the good thing about oil-based products: they naturally preserve themselves.

The Hidden Cost: How Fillers Can Irritate, Sensitize, or Disrupt Skin

Filler ingredients don’t just take up space in a formula; many of them actively work against the skin. Synthetic fragrance compounds, dyes, and texture enhancers are some of the most common irritants in modern skincare.

In the short term, they can trigger redness, stinging, and burning, especially for anyone with a compromised barrier. Over time, repeated exposure can lead to chronic low-grade inflammation, a weakened moisture barrier, and increased reactivity to everything else in your routine. This is why so many people feel stuck with “sensitive skin”: it’s often not their skin at all, but the constant assault of filler-heavy formulas that create a cycle of irritation their skin never gets a chance to recover from.

The Most Common Problematic Fillers in Skincare

Artificial Fragrance

Artificial fragrance blends in skincare are complex mixtures of dozens of chemicals formulated solely for scent, not skin health. Sadly, they are in the vast majority of commercial skincare products, and ironically, they are a leading cause of cosmetic contact dermatitis. Studies show that fragrance allergens are among the most common triggers in patch-testing for allergic reactions.

Beyond causing redness, stinging, and burning, especially in sensitive, dry, or already compromised skin, there’s growing evidence that repeated exposure to fragrance-related compounds may interfere with hormonal signaling. For example, certain fragrance-associated phthalates and synthetic musks are recognised endocrine disruptors that engage hormone receptors, potentially contributing to longer-term skin barrier dysfunction and systemic effects.

Dyes & Colorants

Artificial dyes and colorants add nothing to your skin; they exist purely for aesthetics. Ingredients like FD&C dyes, iron oxides, and even mica can trigger sensitivity, especially around the eye area, where the skin is thinner and more reactive.

Brands often rely on these pigments to make a product look more active or appealing, even when the color has no connection to real therapeutic benefit. In many cases, the bright blue “hydrating” serum or green “calming” cream gets its color from synthetic dyes that do more for marketing than for your skin.

Silicones, Plasticizers & Texture Enhancers

Silicones and texture-enhancers are used to make products feel silky or instantly “hydrating,” but they don’t really provide any real nourishment. I consider them purely sensory ingredients. The bigger issue is that these film-formers are almost always combined with other ingredients you don’t want held against your skin, like fragrance, dyes, preservatives, or unstable actives that should be easily removed, not sealed in. Because silicones are more challenging to wash away, they can build up on the skin over time if your cleansing isn’t thorough. I feel it immediately when someone uses silicone-heavy products on me during a facial: that plasticky, smothered coating that makes my skin feel trapped. They create the illusion of moisturization without supporting barrier health.

And once they’re rinsed down the drain, certain silicone compounds persist in the environment and bioaccumulate, something documented in environmental monitoring studies.

Stabilizers & Thickeners

Stabilizers and thickeners are textural fillers and don’t offer anything meaningful to the skin itself. Their purpose is structural: to shape the feel of a formula, not to nourish or repair. In many products, these ingredients make up the bulk of the formula while the actual actives appear in very small amounts- just enough to make a marketing claim.

Why Brands Use Fillers (Even Though They Don’t Help Your Skin)

Brands rely on fillers for a few predictable reasons. Cost is the biggest. Stabilizers, polymers, silicones, dyes, and synthetic fragrances are far cheaper than high-quality botanicals or meaningful concentrations of actives.

Fillers also help manufacturers meet sensory expectations. People are conditioned to believe a face cream should smell a certain way, glide a certain way, and have a specific color or thickness, even if none of that improves skin health.

Finally, there’s marketing. Bright colors, silky slip, and a strong artificial scent often sell better than an unpadded formula that actually delivers results. The outcome is a product designed to please in the moment rather than support the skin long-term.

How to Spot Fillers on an Ingredient Label

The first 5–7 ingredients make up the majority of any formula, so that’s where you’ll see whether a product is built on meaningful ingredients or padded with cheap ones. If fragrance/parfum appears anywhere high on the list, that’s an immediate red flag. I personally avoid any product containing fragrance at all, even if it is low on the ingredient list, and advise my clients to do the same.

Color additives appear as CI numbers, FD&C dyes, lakes, and mica, none of which contribute to skin health.

Silicones are easy to identify by names ending in –cone or –siloxane, and polymers by endings like –acrylate, –polymer, or –copolymer. These ingredients aren’t inherently harmful, though there is plenty of documentation that certain polymers can trigger contact dermatitis. Their purpose is texture or aesthetics, not to nourish the skin.

What Formula Integrity Looks Like

True formula integrity means a product is built on high concentrations of whole-plant oils, extracts, and naturally aromatic compounds- ingredients that inherently carry nutrients, antioxidants, and barrier-supporting compounds.

Every component in the formula should serve a purpose, not just improve texture or scent. When there’s no added water, you remove the need for preservatives, emulsifiers, stabilizers, synthetic fragrances, or aesthetic fillers entirely.

The result is a short, intentionally constructed ingredient list where each line carries active value from top to bottom, rather than a long label padded with substances that do nothing for the skin.

The Bottom Line: Don’t Pay for Irritation

Fillers don’t strengthen the skin, they don’t support long-term results, and for many people, they can increase the likelihood of sensitivity or irritation. If a product is built on dyes, synthetic fragrance, polymers, or texture enhancers, you’re usually paying more for the feel and presentation than for meaningful function.

Take a moment to look at the labels on the products you already own. Notice what shows up at the top of the list, and whether those ingredients are actually doing anything for your skin. Once you start paying attention, the patterns become apparent.

And if you prefer formulas where every single ingredient has a purpose, that’s precisely the philosophy behind my own work. No fillers, no padding, no unnecessary additions. Just concentrated, functional plant compounds chosen because they actively benefit the skin.

Resources

https://pubmed.ncbi.nlm.nih.gov/14572300/

https://pmc.ncbi.nlm.nih.gov/articles/PMC10051690

https://www.mdpi.com/2673-4184/1/4/20

https://pmc.ncbi.nlm.nih.gov/articles/PMC7355424

https://pmc.ncbi.nlm.nih.gov/articles/PMC8501444