Skin’s hydration is not as simple as putting some water on it, as it will not penetrate. The surface of the skin is predominately hydrophobic, which means that to go through it, you need ingredients that can match the chemistry of the skin and still “carry” water along with.
In your opinion, what are some lesser-known hydrating ingredients in skin care?
I am a big fan of hyaluronic acid (HA), which is anything but lesser known. Despite being a wonder, attention must be paid to this ingredient as not all of its forms created equally.
HA is a naturally occurring substance in the connective tissue. Chemically it is made of a repeat unit (monomer) not too different from glucose, and it is part of the cartilage, helping keep collagen in its desired state of hydration (which also preserves it from degradation). The best formulations that incorporate HA should have a blend of different “sizes” (or molecular weights) of this molecule to ensure penetration through the skin as well as time release ability for those larger ones that diffuse through the skin slower.
Besides HA in multiple sizes, I am a huge fan of SYN®-HYCAN, a synthetic tripeptide that can boost production of your own HA and help fight skin sagging and improve collagen fibrillogenesis. (Our bodies tend to like best what they can produce naturally as opposed to what we put into them). When properly formulated, this ingredient can penetrate deep into the layers of the skin. It is believed to not only boost hydration but also collagen production.
- Urea is also a wonder ingredient. Loves water, is a small molecule and fairly compatible with skin, which translates into ability to drag hydration deep into the layers of the skin where it is not only very necessary but hard to get into.
- Clays are also amazing to boost hydration. They come “premoistened” in a formula (dissolved in water) and can redistribute hydration to ensure that is located where most needed.
- Cellulose derivatives can create a perfect hydration layer on the skin, protecting it and leaving a great feel behind. Great in water-based serums for very oily skin type that can be prone to clogging when using regular moisturizers.
- Vitamin B3 (niacinamide). Can penetrate skin and drag water too, also collagen production stimulant (therefore increasing elasticity). Best when formulated with HA for hydration purposes. It also helps with reducing inflammation, it helps with spot correction (reduces hyperpigmentation), and it is an antioxidant (antiaging).
- Sucrose and sodium chloride. So understated and underrated. Both great to “fix” water and avoid loss of hydration. Readily available, inexpensive and incredibly easy to incorporate into formulations. In that same note, honey must also be considered, which also has amazing antiseptic properties.
What are some good hydrators to look for if you have sensitive skin?
All the ones above are great for sensitive skin. When in doubt opt for more inert ingredients, which are those that are “larger molecules”, such as higher molecular weight HA and SYN-HYCAN. Stay away from products with large concentrations of vitamin B3, as it can irritate skin. Same applies to retinol and even vitamin C (this latter not so much for the actual active but because of the pH that it requires to exist, pretty acidic). Careful with those “all natural” promises that can contain naturally occurring ingredients that can cause allergic reactions.
What are some good hydrating ingredients with additional benefits?
As mentioned above, vitamin B3 is a great one. Not only helps boosting hydration and promoting collagen production but it is also anti-inflammatory and reduces hyperpigmentation. Probiotics can also help with the overall health of the skin through cell restoration, which promotes collagen production and in turn water retention, which increases hydration.
Honey promotes hydration and has incredible anti-bacterial properties, which makes it also a natural preservative. Same can be said (to a lesser extent) for common table salt (sodium chloride) and sucrose.