One of the most common things I’m asked is, “Does it matter what order I apply my moisturisers in?” Another is, “Why do you say mineral oil is a good moisturiser when it doesn’t contain anything that’s good for your skin?” The answer to both these questions lies in the concept of layering.
|The best type of layering. (Picture credit: Elin B)|
First, a reminder about moisturising – it’s all about putting water back into your skin. There are three main types of moisturisers I’ve mentioned before in more detail – briefly, we have:
Occlusives – these are greasy oils that block water from evaporating. Common examples are petroleum jelly, mineral oil (both super effective), lanolin, silicones (e.g. dimethicone), olive oil, carnauba wax, and beeswax.
Humectants – these are water-attracting molecules which grab hold of water and slow down its evaporation. Examples are glycerin/glycerol, hyaluronic acid, propylene glycol, sorbitol, pathenol, and honey.
Emollients – these lighter oils sink into the skin and replace natural skin oils, helping to bind the skin cells back together into a nice solid layer, which feels soft and smooth to the touch. Examples include silicones, isopropyl palmitate, jojoba oil, propylene glycol, and vitamin E.
You can find more examples of each of these ingredients in the original article. As you can see, some ingredients can do more than one thing.
The main scientific concept that’s at play here is that oil repels water. You know how when you put oil and water together, the oil and water don’t mix, and when you put a greasy spoon into plain water, you can’t scrub the grease off without adding soap? This is exactly how layering works!
The other thing to remember is that water evaporates, but oils don’t.
So say you put an oil-only moisturiser (which would have emollient or occlusive actions) directly on dry, thirsty skin, then top it with a water-based moisturiser (which probably contains some humectants). What happens is that the oil stops the water from getting through to the skin, and even though some of the emollient oils may sink into the skin and make it softer, there’s minimal water reaching your skin before it evaporates. Your moisturiser is actually not doing much moisturising at all!
However, your body is full of water, so this will still prevent water from evaporating through your skin. But it does mean that it’ll take a lot longer for the water to rise through your skin and build up in the upper layers that need hydration. It’s not necessarily that bad, but also won’t give any immediate relief.
Now what happens when you do the reverse, and apply watery moisturiser first, then top with an oil-based moisturiser? This time, the water is right next to your skin, and the oil actually seals in the water so it has time to enter your skin. After the watery layer is mostly absorbed, the emollient oils will do their job and the occlusive oils keep the whole shebang in your soft, hydrated skin.
So even though mineral oil might not directly contain anything “good for your skin”, it’s excellent at trapping water next to your skin for absorption.
Does it really matter?
In reality, most moisturisers you buy will have water as a main ingredient, so you won’t fall into the trap of doing Option 1 and not-moisturising with your moisturiser (it’s not just there to make it cheaper to produce!). Most moisturisers will also have a blend of all three types of moisturiser, so you don’t have to think too much about layering, as all three will reach your skin. Additionally, the rubbing-in action will make the layers less distinct.
However, if you use any pure oils in your routine (e.g. rosehip, coconut, olive, mineral oil (aka baby oil or Bio-Oil)) or thick, water-free body butters, then keep in mind that to actually add moisture to your skin quickly, you’ll need to let water reach your skin somehow.
The most effective order of layering then, if you want maximum moisturisation, would be:
– Immediately after a shower (when your skin is still damp with water)
– Apply a humectant-rich moisturiser
– Add an emollient-based moisturiser
– Seal it all in with an occlusive oil.
Applying your moisturisers immediately after a shower (or even in the shower) will trap water next to your skin – think of it as a free moisture boost!
What about treatments?
As you might expect, it seems sensible to apply treatments and serums as close to your skin as possible, so they’re not diluted down by the time they reach your skin…but what if you have two treatments? What order do you apply those in?
Again, it’s down to water – the most effective option if you want to play it safe would be water-soluble ingredients first, oil-based ingredients second. An easy-to-remember rule of thumb is to apply the water-based serums first before the oily treatments, and to wait in between applying different treatments. Then after the treatments are on, you can slather on your plain-Jane moisturisers.
None of these are hard and fast rules – if you use a small amount of oil, it’s incredibly unlikely to interfere with absorption, and layers on your skin don’t stay intact for long, so most ingredients will eventually reach your skin. But these general rules of thumb should give your products the best chances of working as effectively as possible.