Paula's Choice Skin Balancing Pore-Reducing Toner

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

Studies have found adenosine may also help with wound healing.

In skincare products, Adenosine is usually derived from yeast.

This ingredient has skin conditioning, anti-inflammatory, and humectant properties. Humectants help hydrate your skin by drawing moisture from the air. This helps keep your skin moisturized.

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.

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 ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.

A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.

Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.

Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.

Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.

The skin's ability to produce ceramides gets disrupted in skin conditions like eczema. This in turn weakens the skin barrier and applying ceramides topically has been shown to replenish what's been lost to restore barrier function.

Most of the studies with Ceramide AP test it as part of a multi-ceramide complex; studies reinforce ceramide AP's role in rebalancing ceramides in skin and improving skin hydration.

EOP stands for a linked Ester fatty acid, a linked Omega hydroxy fatty acid, and the Phytosphingosine base.

What makes Ceramide EOP special is its ultra-long fatty acid chain; this unique structure allows it to bridge the lipid layers in your skin barrier to prevent water loss (something no other ceramide can do).

Low levels of Ceramide EOP have been found in people with eczema and psoriasis.

Using it together with other ceramides, cholesterol, and linoleic acid have been shown to meaningfully improve hydration and reduce water loss.

In one clinical study, a regimen using Ceramide EOP, NP, and AP led to significant symptom improvements in patients with eczema, psoriasis, and dry skin in just 4 weeks.

You'll usually see concentrations between 0.1-0.5% in formulations. Overall, this is a well-tolerated and safe ingredient for cosmetic use.

Studies show products formulated with NMF ingredients help strengthen our skin's barrier. Having a healthy skin barrier reduces irritation and increases hydration. Our skin barrier is responsible for having plump and firm skin. It also helps protect our skin against infection, allergies, and inflammation.

Fun fact: Phytosphingosine is abundant in plants and fungi.

More ingredients that help boost collagen in skin:

This is a great ingredient for dry, compromised, or aging skin; our skin starts to produce less cholesterol with age.

Research shows cholesterol works best in combination with ceramides and fatty acids, the other two major components in your skin barrier.

Cholesterol is also a well-establish penetration enhancer and can help other actives absorb more effectively.

Cosmetic-grade cholesterol is usually derived from lanolin but plant and synthetic options also exist. We recommend reaching out to the brand if you have questions about their source of cholesterol.

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:

Emulsifiers help stabilize a product. They do this by preventing ingredients from separating, such as oils and water which do not mix naturally. Surfactants reduce surface tension, making it easier to rinse pollutants off skin.

Due to its relation to lauric acid, it may provide antimicrobial benefits.

Because it is not a free-fatty acid or alcohol, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

As a humectant, it pulls water into the skin. But it's a pretty minor moisturizing ingredient compared to other humectants, like glycerin.

Interestingly, it can act as a mild penetration enhancer. One in vitro study on human skin found a 12% concentration upped the absorption of mometasone furoate (a medicinal ingredient used to treat inflammatory skin conditions) up to 7%.

This ingredient is typically used at levels of 0.1-10% depending on the role it's playing.

A patch test study on eczema patients didn't find a significant increase in irritation versus the control group, but the potential for irritation rises at higher concentrations.

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.

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.

Its main job is chelation; this is a fancy word to say it grabs onto metal ions and neutralizes them. This is because even purified water in cosmetics contains trace amounts of metals that can cause big problems in a formula.

These trace metals can break down actives faster, cause discoloration, promote rancidity in oils, and make preservatives less effective. Trisodium EDTA binds to these metals and takes them out of the equation so your products can stay stable and effective for longer.

There's also an added bonus: by neutralizing the metals ions that bacteria need to thrive, this ingredient also acts as a preservative booster.

The Cosmetic Ingredient Review has concluded this ingredient to be safe as used in cosmetic formulations. It is not considered an irritant, sensitizer, and is barely absorbed through the skin.