Emollient
An ingredient that makes skin feel smooth and softened.
Emollients act as spackle to fill in cracks between flaking cells. They also help smooth down the edges of cells that are in the process of shedding, thus eliminating roughness. The smoother your skin, the easier it is for light to reflect + give the impression of a glow; emollients can help make this happen.
Typically, the effect is only temporary + disappears when the emollient is washed off.
That said, certain emollients can apparently help repair skin barrier function. Improving or supporting your skin barrier enables your skin to better keep itself moisturized all on its ownsome.
It’s possible for an emollient ingredient to also act as an occlusive (traps in water) and/or humectant (water attractor).
Exfoliant
Our skin naturally has a process of shedding old skin cells to make way for fresh ones every 28 days or so.
So why would we try doing it ourselves?
Sometimes, we might want to freshen dull-looking skin by loosening up + washing away skin cells that are about to go. We might also want to preventatively remove dead skin cells to reduce the possibility of it clogging pores while shedding, which can result in acne.
Exfoliants can be physical like a scrubbing tool or granular substance, chemical such as AHA’s (Alpha Hydroxy Acids), or an enzyme.
Though they can be helpful at times, it’s best not to overdo it with these. Too much can mean mucking with the integrity (think strength) of our skin barrier.
Humectant
An ingredient that attracts moisture to itself.
When applied to skin, it will draw moisture to the visible top layer of skin (aka, our bella, the stratum corneum) as that is where the humectant is sitting. Simply, it attracts water to your skin surface.
There’s some discussion about where humectants typically draw that moisture from.
In theory, a humectant will draw from whatever moisture is nearby. If air is humid, that’s available to draw from. If air is dry, it will draw mostly from deeper layers of skin.
If humectants draw from deeper skin layers too frequently, it can apparently cause a borrowed-time effect. Meaning, leading to increased skin dryness down the line.
This isn’t a given. Or a “humectants are bad” concept. They can be useful. But worth being aware that if there’s an overleaning disbalance (you live in a dry climate or maybe heavily use them in high amounts), they could possibly be why you’re experiencing dry skin a bunch.
Occlusive
An ingredient that helps prevent the evaporation of water from our skin surface into the air by creating a seal or barrier atop our skin.
It doesn’t add moisture, only prevents or reduces the loss. The effect is temporary + ends when washed off.
When the air around us is dry, our skin can lose more moisture into the air than normal. When air is humid, this moisture loss is reduced and it’s easier to keep our skin looking moisturized.
The general effect of losing moisture from our skin into the air is called Transepidermal water loss (TEWL or TWL). It’s normal. The healthier our skin barrier is, the less moisture tends to escape.
Our skin oils atop our skin + lipids between our cells exist as natural occlusives that help trap in moisture. When our natural barrier is compromised, has been stripped off, or isn’t functioning at its best, this moisture loss can be more rapid than would normally be.