Spoiler - There's no such thing as 'filler ingredients' in formulations.

The age old marketing line: “Nasty cosmetics, full of fillers.” It’s a phrase we have all heard in marketing campaigns for years—but is there actually any truth to it?

Speaking from a formulator’s point of view: not really. The idea that cosmetic products are bulked out with unnecessary ingredients implies lazy chemistry. Ouch.

Let’s be real. Formulating a skincare product is a complex, highly intentional process. There are countless factors a formulator has to consider—from safety and stability to natural or organic certifications, product efficacy, texture, appearance, packaging considerations, and more. Oh, and let’s not forget the cost per unit. By the time we balance everything, it can feel a bit like conjuring rabbits out of hats.

The Basics of a Thoughtful Formulation

Every ingredient in a formulation is chosen for a reason—whether it’s structural, functional or supportive and often, all of the above.

Take a basic foaming facial cleanser, for example. Obviously, we need cleansing agents (functional). But those need a base, typically water (structural). Let’s clear something up here: water is not “diluting” your product—that’s one of the biggest myths in skincare marketing.

Now, because we’ve introduced water, we’ve created a risk for microbial growth. So, we need preservatives (supportive). But we’re still left with a watery, unstable product—not very consumer-friendly. So we add natural gums or polymers (structural) to provide thickness, texture, and shelf stability.

From there, we fine-tune the formula with ingredients that improve performance, feel, and benefits—like humectants for hydration, mildness enhancers, vitamins, minerals, antioxidants, and oils. These aren’t “fillers”—they’re active, supportive components with real purpose.

The Bottom Line

This is just a very basic overview of one type of formulation, and we haven’t even touched on all the regulatory and performance standards that need to be met. But the core truth stands: every ingredient serves a purpose. If something doesn’t belong, it doesn’t get added. It’s that simple and as I always say, context is everything!

So, the next time you hear a brand or skincare therapist slamming a product for being “full of fillers,” consider it a little red flag. A truly knowledgeable professional doesn’t need fear-based messaging to earn your trust—or your respect.

And if you’re unsure? You know who to ask.

— The Clinic’s Formulator