This is a question that rarely has an answer.
Think about food—let’s say a big pot of chili. What’s the star ingredient? Is it the meat? The beans? The tomatoes? The chipotle peppers? If you removed any of those ingredients they’d certainly be missed, but I’m not confident I’d call any of them the “star”. The chipotles might be your favourite thing to put in chili for their wonderful smoky spice, so you might call them your signature ingredient, but if you took out the tomatoes you’d end up with a drastically different end product. They are both important.
Something similar is true in cosmetic formulation. The distilled water or preservative in a lotion certainly aren’t going to be the most exciting ingredients in the formulation, but without either of them, the formulation will fail.
Here are a few things to think through/consider:
- The more of an ingredient that is present in a formulation, the more likely it is to be important
- If an ingredient is key to the stability of the formulation (emulsifier, solubilizer, preservative), it’s important
- If an ingredient is part of the core function of the product (a surfactant in a cleanser, for example), it’s important
- If an ingredient is present below 1% it is less likely to be important, but that really depends on the ingredient. Some ingredients are very effective at low levels (preservatives, essential oils, some actives), while others might just be included for marketing purposes (carrier oils & butters used below 1% are usually just for show). For this category it’s really important you know your ingredients and understand usage rates.
- Fragrance and/or essential oils are usually not the lynchpin of a formulation, though this can vary with the formulation, so make sure you understand why those ingredients are present. If it’s a perfume, for instance, those ingredients would really matter!
- If you’re looking at re-creating a commercial product, the ingredient that’s being bragged about on the label is rarely all that important; it was chosen for the label because it sounds nice, not necessarily because it’s a key part of the formulation. An example would be an “argan oil hair serum” that is mostly cyclomethicone. If you start your re-creation with argan oil you’re starting miles away from the original—there’s likely less than 5% argan oil in the commercial product because the slip and lightweight feel you’re familiar with comes entirely from the cyclomethicone.
Posted in: Ingredients