The Left Brain’s lippy reply:

Hi John, thanks for your question. It’s always nice to hear from our male members. (That sounds strange but you know what I mean.)

Lickable lips

It’s true that microbes need water to grow and that the level of water activity is one of the factors that determines how hospitable an environment is for microbial growth. But if you’re presuming that preservatives are only needed in aqueous products then you’re sadly mistaken. Even for anhydrous formulas, you have to consider if the product is likely to be pick up moisture that could support bacterial growth. In the case of lip glosses, this is pretty likely because of the moist environment the lips provide.

Lip gloss ingredients

How can you find the preservative in a lip gloss? I’ll show you a typical product Neutrogena MoistureShine Gloss:

Bis Diglyceryl Polyacyladipate 2, Petrolatum, Lanolin Oil, Microcrystalline Wax, Maleated Soybean Oil, Isopropyl Palmitate, Quaternium 18 Hectorite, Beeswax, Ascorbyl Palmitate, Propylene Carbonate, Jojoba Seed Oil (Simmondsia Chinensis), Tocopherol, Evening Primrose Oil (Oenothera Biennis), Safflower Seed Oil (Carthamus Tinctorius), Aloe Barbadensis Leaf Extract, Rosa Canina Seed Extract, Tangerine Oil (Citrus Tangerine), Rose Flower Oil, Dipropylene Glycol, Flavor, Propylparaben, Mica, Iron Oxides, Titanium Dioxide, Red 7 Lake, Red 6, Blue 1 Lake, Yellow 6 Lake, Red 6 Lake, Yellow 5 Lake

As you can see, the formula is primarily composed of non-water, oily materials. And hidden toward the end of all those ingredients, you’ll find that “propylparaben.” This is a common oil soluble preservative. While it’s not really necessary to protect the formula during manufacture or while it sits on the shelf, it does provide protection from bacteria that the product might come in contact with once you start to use it.

By the way since I’m talking lip gloss ingredients, I should tell you that my all time favorite lip gloss is Almay Ideal Lipgloss because it contains the best sounding ingredient ever: “Synthetic Fluorphlogopite.” (Which should never be confused with natural Fluorphlogopite.)

The Beauty Brains bottom line

A good cosmetic scientists thinks about how to protect her product through its entire life cycle - which includes before and after the consumer buys it. And that means you might have to add a preservative you didn’t even know you needed.

What’s YOUR favorite lip gloss? Leave a comment for the rest of the Beauty Brains community.