onTop Light Touch Sunscreen Lotion SPF50+ PA++++

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.

Two of its biggest selling points are efficiency and stability:

Most of the other chemical filters are considered "photostable" if they can last for two hours.

Because this ingredient is oil-loving, it can sit neatly into the oil phase of emulsions and shines in water-repellent/water-resistant formulations.

The EU and Canada allow it to be used up to 10% and Japan allows it up to 5%.

Unfortunately, it's not yet an FDA approved sunscreen agent so you won't be able to find it in sunscreens in the US.

Safety-wise, it has a pretty solid record: the EU's Scientific Committee on Consumer Safety (SCCS) has reviewed it and found low skin absorption, no capacity to produce skin irritation or photo-irritation.

In vitro testing has found less than 0.1% of the applied dose is absorbed by the skin over 24 hours (mostly due to its large molecule size).

Fun fact: This ingredient even has anti-inflammatory properties similar to those of ketoprofe, an anti-inflammatory medication.

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.

On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.

Typical use levels in a formula run about 1-5%.

Another pro?

It's exceptionally photostable, barely degrades in sunlight, and acts as a "bodyguard" for less stable filters.

That's why you'll see it paired with avobenzone or octinoxate; this team up ensures they keep working through sun exposure.

Safety reviews have been reassuring across the board. This ingredient shows low absorption through the skin, rarely irritates, and lab studies found it doesn't act like a hormone in the body (a concern that's been raised about some older sunscreen filters).

On maximum concentrations:

In 2026, the US F.D.A finally added it as an OTC sunscreen ingredient at concentrations up to 6% for adults / children 6 months and older

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

Safety-wise, the CIR Expert Panel has concluded it to be safe in cosmetics when formulated to be non-irritating and non-sensitizing.

Free stearic acid is a C18 fatty acid that the Malassezia yeast can substrate, so this ingredient may not be fungal acne safe.

Because it has a neutral charge, it is compatible with a wide range of ingredients and stays stable across a broad pH range/water hardiness conditions.

Patch testing has shown it to have the lowest irritation potential among common cleansing surfactants (like SLS).

Typical use levels range from 5-20% in rinse-off cleansers.

One thing worth knowing: The American Contact Dermatitis Society named the parent family, alkyl glucosides, "Allergen of the Year" in 2017. The prevalence of allergy is pretty low but be sure to patch test if you've reacted to "gentle" or sulfate-free cleansers before.

This ingredient is fungal acne safe because the fatty alcohol portion of this ingredient is not within the C11-24 chain length that Malassezia can metabolize.

This ingredient is biodegradable and commonly available in natural/COSMOS-certified grades.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

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.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin.

In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum.

You'll likely see use concentrations quite low, usually 0.1-0.2%.

Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure skin.

It is non-ionic and forms a triple helix in solution. This is just a fancy way of saying it builds a smooth, cushiony, and non-sticky gel that feels silkier than many other gums.

Another perk of this ingredient is that it is very sturdy and holds up across a wide pH range (~2-11). It's also good at resisting heat and hydrolysis.

Since it holds water at the skin surface, it can provide some light hydration as well.

Typical use levels are around 0.25-2%; formulators usually use 0.2-0.5% to thicken lotions and up to 2% for a firmer gel base.

This ingredient has been found safe in cosmetics with no meaningful evidence of skin sensitization.

Because it’s oil-soluble, THD dives deep into your skin’s fatty layers (think ceramides and cholesterol) to fight off the kind of free radicals that mess with your skin barrier. This makes it a great pair with water-based vitamin C (ascorbic acid) that mainly works on the surface.

Even at just 0.1%, THD is already showing great antioxidant activity. When used up to 2%, it helps keep your skin happy and calm, especially when it’s stressed from pollution or sun.

Want to fade dark spots or tackle hyperpigmentation? You’ll want 5% or more. Pairing it with brightening buddies like niacinamide or licorice root gives even better results. One study even used 30% THD with other brighteners and saw real results on stubborn discoloration, even in melasma-prone skin.

A note on THD: It’s has a slightly silky, oily texture and usually shows up colorless or pale yellow (though the exact shade can vary by supplier).

While you can sneak it into water-based formulas, it really shines when paired with silicones or oils, which help your skin soak it up better.

THD is pretty stable, but it’s still vulnerable to degradation like ascorbic acid. Too much light or heat (above 113°F / 45°C) can break it down over time. Go for dark and opaque packaging that keeps it safe and shady!

Read more about other types of Vitamin C:

Beyond anti-aging, resveratrol is also valued for its skin-brightening and soothing properties.

Some forms of resveratrol appear to be more effective than others. Resveratrol isobutyrate and resveratrol butyrate are often cited as more stable derivatives.

Research also suggests these two forms have stronger effects on Type I collagen stimulation and inflammation reduction compared to basic resveratrol.

Resveratrol is naturally unstable and can degrade when exposed to light and oxygen. Well-designed products often use stabilized derivatives, airless or opaque packaging, and supporting antioxidants to help maintain effectiveness on skin.

A note on resveratrol as a retinoid alternative:
While resveratrol offers antioxidant protection, inflammation control, and some collagen-supporting benefits, it does not replace retinoids in terms of cell turnover or acne treatment.

However, it can be a useful option for people with retinoid sensitivity or intolerance, or for those looking to support skin health without irritation.

Fun fact: Resveratrol is naturally found in grapes, peanuts, and berries, which is why it’s frequently associated with wine and grape-derived skincare ingredients.

In real-world studies, products containing this extract were associated with fewer clogged pores and fewer acne lesions.

Lab studies show milk thistle has been shown to:

Research on this ingredient also found a sustained and significant decrease in acne lesion counts (a ~45% improvement after 6 months and ~59% at 12 months).

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 CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

Read more about some other popular AHA's here: