Cetaphil Daily Oil-Free Moisturizer SPF 35 Versus Supergoop! City Sunscreen Serum SPF 30

The ethylhexanol in this ingredient is a fatty alcohol and helps hydrate your skin, similar to oils. It is an emollient, which means it traps moisture into the skin.

According to manufacturers, Ethylhexyl Salicylate absorbs UV wavelength of 295-315 nm, with a peak absorption at 307-310 nm. UVA rays are linked to long term skin damage, such as hyperpigmentation. UVB rays emit more energy and are capable of damaging our DNA. UVB rays cause sunburn.

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

(Part of the reason that sunscreens need to be frequently re-applied is due to the photo instability of many chemical sunscreen filters)

Currently, homosalate is approved in concentrations up to 10% in the EU and 15% in the US. The FDA is currently doing further research on the effects of homosalate, and it is possible that these approved concentrations will change in the future.

Those who are using ketoprofen, a topical anti-inflammatory drug, may experience an allergic reaction when using octocrylene. It is best to speak with a healthcare professional about using sunscreens with octocrylene.

The EU allows a maximum of these concentrations:

D-panthenol is also known as dexpanthenol. Most cosmetics use dexpanthenol or a mixture of D and L-panthenol.

Panthenol is famous due to its ability to go deeper into the skin's layers. Using this ingredient has numerous pros (and no cons):

Like hyaluronic acid, panthenol is a humectant. Humectants are able to bind and hold large amounts of water to keep skin hydrated.

This ingredient works well for wound healing. It works by increasing tissue in the wound and helps close open wounds.

Once oxidized, panthenol converts to pantothenic acid. Panthothenic acid is found in all living cells.

This ingredient is also referred to as pro-vitamin B5.

The unique structure of silica enhances the spreadability and adds smoothness, making it a great texture enhancer.

It is also used as an active carrier, emulsifier, and mattifier due to its ability to absorb excess oil.

In some products, tiny microneedles called spicules are made from silica or hydrolyzed sponge. When you rub them in, they lightly polish away dead skin layers and enhance the penetration of active ingredients.

Another benefit is a bit of UV protection. Vitamin E helps reduce the damage caused by UVB rays. (It should not replace your sunscreen). Combining it with Vitamin C can decrease sunburned cells and hyperpigmentation after UV exposure.

You might have noticed Vitamin E + C often paired together. This is because it is great at stabilizing Vitamin C. Using the two together helps increase the effectiveness of both ingredients.

There are often claims that Vitamin E can reduce/prevent scarring, but these claims haven't been confirmed by scientific research.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!