Skin Aqua UV Acne Defense Milk SPF 35 Versus Skin Aqua UV Moisture Gel SPF 30 PA++

Some studies suggest betaine may support making skin tone more even.

Fun fact: Betaine naturally exists in the skin and the body. In cosmetic products, it can be either plant-derived (most commonly from sugar beets) or synthetically produced for consistency and stability.

Betaine is also known as trimethylglycine.

DHHB has been approved by the EU, Japan, Taiwan, and South America for use up to 10%. Unfortunately, it has not been approved for use in the US or Canada due to slow regulatory processes.

This ingredient is soluble in oils, fats, and lipids.

One component, glabridin, has extra potent antioxidant and soothing properties. It has also been found to block pigmentation from UVB rays in guinea pigs.

Licorice Root also contains a flavonoid. Flavonoids are a natural substance from in plants. Flavonoids also have antioxidant properties.

Another component, glycyrrhizin, has been found to have anti-inflammatory and antimicrobial benefits. This may make licorice root extract effective at treating acne. However, more research is needed to support this.

Liquiritin is one of the flavone compounds found in licorice. It has been found to help lighten skin by preventing tyrosinase from reacting with tyrosine. When the two react, protein is converted to melanin. Melanin is the substance in your body that gives your features pigmentation.

Licorice root is native to Southern Europe and Asia. It has been used in traditional Chinese medicine to help with respiratory issues.

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.

Formulators love it for its stability; its ability to filter UV stays practically unchanged even under intense radiation and it can also help boost the photostability of less stable filters like avobenzone.

It's also a great pick for water resistant products because it's insoluble in water and has a good affinity for keratin.

Because it's a big, heavy molecule, the European Scientific Committee has found to to have very low dermal penetration and negative results for allergenicity.

In vitro testing also showed a low absorption rate and clean results on irritation.

Typical use levels are 1-5% with 5% being the maximum in the EU, Japan, and other markets that allow it. However, this ingredient is not approved yet in the US or Canada.

This ingredient is an emollient, emulsifier, and penetration enhancer. As an emollient, it helps soften and hydrate skin by trapping moisture within. As an emulsifier, it prevents oil and water ingredients from separating.

Hydrogenated Lecithin can form tiny spherical structures made of phospholipid bilayers called liposomes. These liposomes are able to capture compounds inside their structure and deliver them through the skin barrier.

Because phospholipids are a natural component of our cell membranes, this ingredient is inherently compatible with skin.

A 2021 study found lecithin-based surfactants were less harsh and more tolerable comared to Sodium Lauryl Sulfate (SLS).

The small peptides and amino acids (including Natural Moisturizing Factor components like Hydroxyproline, Serine, and Aspartic Acid) help the surface of the skin hold onto water, feel softer, and look temporarily plumper.

This ingredient also has mild film-forming and antioxidant properties with research showing the antioxidant effect is stronger the lower the molecular weight of the peptides.

It's worth being realistic here:

Topically applied Hydrolyzed Collagen conditions the upper layers of skin rather than rebuilding the structural collagen deep in your dermis (the wrinkle-and-firmness benefits people associate with Collagen mostly come from oral supplements in studies, not topicals).

However, recent lab and skin-model work on Hydrolyzed Fish Collagen has shown promising effects on cell viability and wound healing when used as an active.

Typical concentrations range from 0.2-2%, but the percentage can go much higher in rinse-off or hair products (sometimes even above 50%).

Clinical studies on this ingredient showed no irritation, sensitization, or phototoxicity.

If you are looking for vegan collagen, it usually goes by a different INCI name like hydrolyzed soy protein. Vegan collagen is derived from yeast, bacteria, or plant sources.

The results are varied.

A study from 2021 found hydrolyzed collagen increased elasticity and improved wrinkles in 1,125 participants between age 20 and 70. Another study found increased skin thickness in participants between the ages of 45 to 59.

However, It is difficult to prove that oral collagen will end up working on your skin. Many of the studies using hydrolyzed collagen also add several vitamins and nutrients into the test mixture as well.

Further studies are needed at this time.

One of its best party tricks is photostability; it doesn't break down with repeated sun exposure and doesn't generate free radicals in the process either. You'll also see it paired with wobbly filters like avobenzone because it helps stabilize them.

The safety profile is assuring as well. Because it's a large molecule, it doesn't easily absorb into skin and rarely causes irritation.

It's approved in the EU, Asia, and Australia up to 10% and most formulas land somewhere in the 2-10% range.

You won't find it as a sunscreen active in the US, but it can make an appearance as a formula-protecting UV-absorber.

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.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

In this case, the 60 comes from reacting 60 units of ethylene oxide with sorbitan.

Polysorbates are commonly used in medicine and foods.

Read about common types of Hyaluronic Acid here:

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.

It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.

One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.

Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.

Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.

The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.

Most leave-on skincare keeps it at the lower end, often between 0.5-1%.

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!