Benefit Cosmetics Hubba Brow Enhancing Serum

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%.

The Cosmetic Ingredient Review (CIR) Expert Panel evaluated it (along with 22 other acryloyldimethyltaurate polymers) and concluded it's:

Due to its large molecular size, it sits on the surface of skin rather than penetrating it.

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.

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.

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.

Chlorphenesin is soluble in both water and glycerin.

Studies show Chlorphenesin is easily absorbed by our skin. You should speak with a skincare professional if you have concerns about using Chlorphenesin.

Though it can't kill microbes on its own, it works as a good supporting agent when combined with other preservatives like Phenoxyethanol or 1,2-Hexanediol.

This ingredient naturally occurs as piceol in Norwegian spruce needles (~0.4-1.1% dry weight and in cloudberries). Though the cosmetic-grade material is synthesized for purity and consistency.

You'll usually see it used at low levels and suppliers recommend up to 1% added to a water phase.

Safety testing was done at concentrations like 0.05% in SPF products and 0.5% in a Human Repeated Insult Patch Test. The safety evidence is assuring; this ingredient is safe for cosmetics in current use and also holds safety status as a food flavoring as well.

An honest caveat: the "soothing" and "anti-inflammatory" claims come mostly from supplier marketing rather than published clinical trials. The Cosmetic Ingredient Review's own literature search found no useful efficacy studies on this ingredient.

So the antioxidant and preservative-boosting roles are the well supported ones while the calming benefit is plausible but thinly evidenced.

Overall, this is a well-tolerated, low-irritation multitasker that quietly helps a formula stay fresh and stable.

Safety-wise, this ingredient is pretty solid; it's even recognized as a food additive. Both animal and clinical studies found no adverse effects at the levels used in cosmetics.

Industry data shows this ingredient is used up to 45.7% in spray products and up to 33% in powder products.

More research is needed on applying biotin topically. However, taking biotin orally has been shown to help nourish the skin, hair, and nails. They play a role in forming skin-hydrating fatty acids.

Biotin is water-soluble. It can be found in foods such as fish, eggs, dairy, nuts, and meat. Vitamin H stands for "haar" and "haut". These are the German words for hair and skin.

You'll usually find this in concentrations between 0.2-5%.

First, it turns down inflammation so it helps with things like redness and general upset skin.

Second, it acts as an antioxidant which means it helps protect skin from daily stress and damage.

And third, it nudges the skin to make more collagen and rebuild its support structure.

That combination is why the whole Centella family is known for calming skin, strengthening the barrier, fading redness, and giving anti-aging benefits.

It's worth being honest about the evidence here; a lot of the strongest data is on the full extract or a Madecassoside/Asiaticoside rather than Madecassic Acid alone. Reviewers also note more long-term clinical trials are needed to confirm the full potential.

Concentration-wise, this ingredient is rarely used pure and usually shows up as part of a standardized centella extract where reported content ranges from 0.02-3.06%.

Finished products typically run somewhere in the 0.1-10% range depending on the format.

In real-world tolerance tests, a repeat-insult patch test on an eye lotion with 0.2% Centella extract showed no irritation or allergic contact dermatitis in 54 subjects. And a mascara with 0.5% Madecassoside caused neither irritation nor sensitization in 109 subjects.

Allergy risk is very low, but not zero. Centella and its constituents are classified as weak contact sensitizers and some rare cases of allergic contact dermatitis exist.

The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).

Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

It also calms inflammation and acts as an antioxidant so it can help skin heal faster, rebuild itself, and repair a damaged barrier.

And on naming, even though "acid" is in the name, it's nothing like an AHA or BHA exfoliant. It's a gentle firming and soothing ingredient that supports your skin barrier.

Concentration-wise, Asiatic Acid is potent at very low doses and usually shows up as a small fraction of a broader centella extract.

Analyses of centella material put Asiatic Acid reported in the range of 0.2-3% of the extract.

This ingredient is non-sensitizing and guinea pig sensitization testing also found it to be a weak sensitizer. That means the risk of acquiring contact sensitivty is quite low.

Allergic contact dermatitis does exist but is also very rare; documented cases tend to involve prolonged use on broken skin plus co-sensitization to fragrance ingredients.

However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.

Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.

In skincare formulas, citric acid can:

While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.

Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.

Read more about some other popular AHA's here:

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.