Supergoop! Glowscreen Hydrating And Glowing Sunscreen Primer SPF 30 Versus NARS Cosmetics Radiance Face Primer SPF 35

It's actually so reliable that formulators often pair it with shakier ingredients like oxybenzone and avobenzone. Formulators also use it to help dissolve the other UV filters into the oil phase.

One thing to keep in mind: "stable" isn't the same as "strong". On its own, homosalate is actually a pretty weak UV filter so it's better off as a helpful team player that helps boost overall SPF protection.

The safety picture is a bit nuanced but not scary.

This ingredient has a long track record of being gentle and regulators agree it isn't an irritant; EU's Scientific Committee on Consumer Safety found that homosalate is not considered a skin irritant and doesn't raise eye-irritation flags either.

There's talk about homosalate because your skin absorbs a little bit of it into your bloodstream. A 2020 FDA-backed study found homosalate showed up in people's blood levels at the level where the FDA decides to double check.

The EU's Scientific Committee on Consumer Safety (SCCS) also found small amounts in blood and breast milk. They estimated that about 5% of what you apply gets absorbed through the skin.

Due to the debate about whether it might mess with hormones, the SCCS recommended a maximum limit of 0.5% in most products of 7.3% in face creams/pump sprays.

One important thing to keep in mind: in the US, Homosalate is currently labeled "non-GRASE" by the FDA. This sounds alarming but really just means the FDA wants more data to confirm it's safe. It's not confidently saying this ingredient is harmful.

As of now, homosalate is still completely legal and widely used while that research gets done.

The current maximum limits are:

Isododecane's role as a solvent makes it a great texture enhancer. It spreads smoothly on skin and does not leave a sticky feeling behind. Isododecane also helps prevent color transfer in makeup products.

Isododecane is not absorbed into skin.

The chemical name for this ingredient is 2,2,4,6,6-PENTAMETHYLHEPTANE.

This ingredient is often coated with metal oxides like titanium dioxide. Trace amounts of heavy metals may be found in mica, but these metals are not harmful in our personal products.

Mica has been used since prehistoric times throughout the world. Ancient Egyptian, Indian, Greek, Roman, Aztec, and Chinese civilizations have used mica.

This ingredient is commonly used to enhance both UVB and UVA protection due to its unique property in stabilizing avobenzone. It also pulls double duty by boosting water resistance and giving formulas a smooth, spreadable feel.

The EU's Scientific Committee on Consumer Safety (SCCS) has deemed octocrylene to be safe as a UV-filter at concentrations up to 10% (capped at 9% in propellant sprays). The US also permits it up to 10%.

Two things worth knowing:

You'll usually see this ingredient used in concentrations between 2-10% (higher amounts when used as a stabilizer for avobenzone).

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

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!