Wade wonders…I am questioning the efficacy of using a raw material versus a product with a specific formula that might contain these ingredients. For the sake of relevancy, lets use an example—a battle between two of the most highly regarded moisturizers in the cosmetic industry: VASELINE v. AQUAPHOR! So, in one corner, we have the best occlusive money can buy, and in the other, we have a cosmetic chemist’s concoction containing a mixture of moisturizers, including petrolatum. So, does Aquaphor work better than Vaseline simply because it has been formulated to be semi-occlusive (Claim made by Aquaphor’s website)? Which is truly more effective as a moisturizer, and why?
The Beauty Brains respond:
Wade’s question is paraphrased from her (his?) discussion thread in our Forum. The answer has to do with the fact that the best moisturizers work three ways while single ingredients, like petrolatum, only work one way. (And like Sarah Bellum says “I’m always up for a good three way!”) Here are the three modes of action that you want your moisturizer to have along with a brief description of the best ingredients to get the job done.
3 methods of moisturization.
Purpose: To reduce how much water evaporates through your skin. (Cosmetic scientists refer to this as TransEpidermal Moisture Loss or TEWL.) Occlusive agents form a hydrophobic barrier on your skin that keeps the water on the inside. The most effective examples include petrolatum, mineral oil, and dimethicone. Some plant oils help occlude the skin but typically they are included more for their emolliency.
Purpose: In this context I’m talking about adding water to skin and the only ingredient that can really do that is…water. For some product types (like shampoo) water is just a carrier or solvent for other ingredients. But in the case of moisturizing lotions the water contained in the product is also hydrating your skin. (Neither of the examples raised by Wade include this category.)
Purpose: To bind (or even attract) moisture to your skin.
Ingredients known as “polyols” have the ability to hold on to large amounts of water and keep it close to your skin. In some cases they can even absorb moisture from the atmosphere. These ingredients have two drawbacks: they can make your skin feel sticky and when the air is REALLY dry they can actually pull water out of your skin instead of the atmosphere. Examples include glycerin, sorbitol, and hyaluronic acid. Glycerin and sorbitol work pretty well and they’re cheap. Hyaluronic acid can hold hundreds of times its weight in water but it’s really expensive.
Vaseline vs Aquaphor
As Wade noted in the Forum, Vaseline Petroleum Jelly consists solely of petrolatum which is the best occlusive agent. Aquaphor also contains a good slug of petrolatum (41%) but in addition it contains mineral oil, ceresin, lanolin alcohol, panthenol, glycerin, and bisabolol. Based on its placement on the ingredient list, I doubt the product contains very much glycerin but at least theoretically Aquaphor could bind moisture to the skin through humectancy where as Vaseline can not. Mineral oil is also a good occlusive agent (not as good as petrolatum) and the other ingredients don’t really do much. (Note: if the formula contains a high percentage of panthenol, it could contribute to moisturization too.)
Aquaphor may have another advantage which is user compliance. Pure petrolatum is tough to spread across skin and it can be very greasy. A formulated lotion like Aquaphor is much easier to apply and will be more aesthetically pleasing on skin. Therefore, people will be more likely to reapply it which will make it work better in the long run.
Neither one of these products contain water so it would probably best to apply them to freshly showered skin which will be well hydrated.
Which is the better moisturizer? It’s tough to beat pure petrolatum for occlusion but a formula such as Aquaphor is probably the better choice in the long run.