Kiehl's Retinol Fast-Release Wrinkle Reducing Night Serum

Retinol is a gold-standard ingredient for anti-aging. It is a form of Vitamin A and belongs to the class of retinoids that also includes tretinoin.

Why is retinol famous?

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate (long name, huh?) is a synthetic antioxidant.

It is used to help stabilize other antioxidants or prevent the color from changing in a product.

Silica Silylate is a siloxane polymer, meaning it is made up of silicon and oxygen atoms. It is not soluble in water.

This ingredient is a white powder with oil-absorbing, emollient, and anticaking properties.

Silica is a mineral naturally found in our skin. It helps to thicken and smooth the texture of a product. It also acts as an agent for other ingredients by increasing the absorption of other ingredients into the skin.

Silica is often used for absorption and can help reduce shine when products are applied. Silica occurs in naturally in materials like clay and sandstone, and it can also be produced synthetically.

Magnesium Stearate is a salt that is 2 parts stearic acid and 1 part magnesium.

It is a white powder that can be used to add bulk and color to products by binding to oil ingredients.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

Glycerin is already naturally found in your skin. It helps moisturize and protect your skin.

A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin. 

It’s often used to:

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Glycereth-26 is a synthetic ingredient and polyethylene glycol ether of Glycerin. Glycerin is already naturally found in your skin and helps keep your skin moisturized.

It is a humectant and helps add texture to products. It can make your product thicker.

Panthenol is a common ingredient that helps hydrate and soothe the skin. It is found naturally in our skin and hair.

There are two forms of panthenol: D and L.

1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse. 

It is a:

• Humectant, drawing moisture into the skin
• Emollient, helping to soften skin
• Solvent, dispersing and stabilizing formulas
• Preservative booster, enhancing the antimicrobial activity of other preservatives 

Polyglycerin-3 is a 3-unit glycerin polymer.

Like glycerin, this ingredient is a humectant. Humectants help hydrate your skin by drawing water to it.

C12-14 Pareth-12 is created from a mixture of synthetic C12-14 alcohols that have about 12 moles of ethylene oxide.

It is an emulsifying and cleansing ingredient. Emulsifier help prevent ingredients from separating, such as oils and waters.

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Caprylyl Glycol is a humectant and emollient, meaning it attracts and preserves moisture.

It is a common ingredient in many products, especially those designed to hydrate skin. The primary benefits are retaining moisture, skin softening, and promoting a healthy skin barrier.

Ammonium Acryloyldimethyltaurate/Vp Copolymer (let's call it AAVC for short) is a synthetically created polymer. It's used as a film-forming agent and used to thicken the consistency of products.

AAVC is able to increase the consistency and viscosity of products due to its large molecule size. It also prevents ingredients from separating.

Betaine is a common humectant (a substance that promotes retention of moisture). It's known to be gentle on the skin and can help balance hydration.

This ingredient is best for improving hydration and soothing irritated skin. Studies also show it helps even out skin tone.

Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.

On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.

Ethylhexylglycerin (we can't pronounce this either) is commonly used as a preservative and skin softener. It is derived from glyceryl.

You might see Ethylhexylglycerin often paired with other preservatives such as phenoxyethanol. Ethylhexylglycerin has been found to increase the effectiveness of these other preservatives.

Adenosine is in every living organism. It is one of four components in nucleic acids that helps store our DNA.

Adenosine has many benefits when used. These benefits include hydrating the skin, smoothing skin, and reducing wrinkles. Once applied, adenosine increases collagen production. It also helps with improving firmness and tissue repair.

Carbomer is a polymer of acrylic acid. Its main role is to create a gel consistency.

A high amount of carbomer can cause pilling or balling up of products. Don't worry, most products contain 1% or less of carbomer.

Glyceryl Acrylate/Acrylic Acid Copolymer is made up of glycerin and polyacrylic acid. It helps hydrate your skin as a humectant.

This ingredient forms a hydrogel that delivers moisturizing, water-based ingredients to the skin. It is also used to thicken a product and to give it a smooth texture.

Tromethamine helps balance the pH and improve the texture of a product. It is synthetically created.

As an emulsifier, Tromethamine prevents oil and water ingredients from separating. This helps stabilize the product and elongate a product's shelf life. Tromethamine also makes a product thicker.

Glycereth-25 PCA Isostearate isn't fungal acne safe.

T-Butyl Alcohol it is most commonly used as a solvent.

At room temperature, T-Butyl Alcohol melts and has a similar smell to camphor.

Tocopherol (also known as Vitamin E) is a common antioxidant used to help protect the skin from free-radicals and strengthen the skin barrier. It's also fat soluble - this means our skin is great at absorbing it.

Vitamin E also helps keep your natural skin lipids healthy. Your lipid skin barrier naturally consists of lipids, ceramides, and fatty acids. Vitamin E offers extra protection for your skin’s lipid barrier, keeping your skin healthy and nourished.