The INKEY List SuperSolutions Acne Solution 5% Benzoyl Peroxide Cleanser

On top of that, BPO has keratolytic properties to help shed dead skin cells and keep pores from getting clogged.

One of the coolest things about BPO is that bacteria do not develop resistance to it the way they can with antibiotics. That's why dermatologists recommend pairing it with topical antibiotics to keep resistance at bay.

BPO is usually available in 2.5%, 5%, and 10% concentrations. Research has shown that 2.5% tends to be just as effective as the higher strengths while being more gentle on the skin.

The FDA has classified BPO as a safe and effective acne treatment. You'll be able to find this ingredient in over-the-counter products in many countries.

Just so you know, BPO is a known mild irritant. It's common to see dryness, peeling, and some redness when you first start using it. This usually goes away as your skin adjusts.

A very small number of people might develop allergic contact dermatitis from it as patch test studies show positive reactions in about 1-5% of patients.

Once BPO is absorbed into the skin, our bodies turn it into benzoic acid and quickly exits in urine. It's also worth noting that BPO will bleach fabrics and hair, so watch your towels and pillowcases!

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.

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.

It can also form a thin protective film on skin. One study found that a formula using this polymer helped slow down how quickly other ingredients (like DEET) were absorbed through skin.

A 2024 study of over 1,300 patients confirmed that sensitization to this ingredient is rare. It is also non-mutagenic and has a clean track record.

One manufacturer claims this ingredient to have a pH range of 2-8 and to be biodegradable.

This ingredient is also known as Sepimax Zen.

You might see people debate whether Sodium Chloride is comedogenic, but there actually haven't been any comedogenic tests done on it. Either way, the overall formulation of a product matters a lot more than any single ingredient.

You might see this ingredient used in scrubs as a primary exfoliating ingredient.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

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.

For haircare friends: this ingredient is not a silicone.

According to studies, low molecular-weight hyaluronic acid can:

One study from 2011 found ultra-low weight HA to show pro-inflammatory properties. Another study from 2022 found it to downregulate UV-B induced inflammation.

Hydrolysis is a process of changing a molecule using water or enzymes.

This ingredient is water-soluble.

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.

This ingredient is derived from isobutane. It is the simplest form of a tertiary alcohol. Due to its chemical structure, it is more resistant to oxidation.

Some sources online claim T-Butyl Alcohol is a fatty alcohol. However, it is not considered one due to its chemical structure.