Kiehl's Powerful-Strength Dark Circle Reducing Vitamin C Eye Serum

As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.

Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.

Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.

In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.

This ingredient is organic, colorless, odorless, and non-toxic.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

Vitamin C is best used for brightening skin. It improves dark spots, acne scars, and hyperpigmentation. This is because it blocks the process of skin darkening when exposed to UV.

Remember: Vitamin C should not replace sunscreen!

Your skin uses vitamin C to build collagen. Collagen is one key component in having a strong skin barrier and plump skin. Vitamin C also plays a role in regulating collagen, thus making it effective in improving wrinkles and fine lines.

Ascorbic acid shows potent antioxidant activity. As an antioxidant, it helps fight free-radicals. Free-radicals are molecules that may damage your skin cells. These antioxidants also protect skin against UV damage.

The best formulations include Vitamin E and/or ferulic acid. These two ingredients help stabilize and provide a boost in the benefits of ascorbic acid. This is because ascorbic acid becomes unstable when exposed to UV and air. In fact, you can tell your ascorbic acid has oxidized when it turns an orange-yellow color.

Ascorbic acid is generally compatible with other ingredients. However, using ascorbic acid with other active ingredients might cause irritation. Two ingredients: copper ions and benzoyl peroxide, will inactivate ascorbic acid completely.

Read more about other types of Vitamin C:

Foods rich with vitamin C include oranges, strawberries, broccoli, bell peppers, and more. When consuming Vitamin C, your skin receives a portion of the nutrients.

As an emollient, it can help the skin feel soft and hydrated. It is also used to reduce frizz in hair products.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Stay hydrated!

Lauroyl lysine is barely soluble in water.

This ingredient is considered a modified starch. Starch can also be found naturally in plants.

One study from 1991 found that 5% of this ingredient enhanced titanium dioxide SPF by as much as 40%. The study found 1% titanium dioxide had a 5.6 SPF and adding 5% of aluminum starch octenylsuccinate boosted it to an SPF of 8.1

Although “aluminum” in an ingredient name can raise red flags for some consumers, the form and usage context matter significantly. For typical topical applications, there is no substantial evidence of health risks - such as cancer, neurotoxicity, or systemic “aluminum overload.”

Ci 77891 is commonly found in sunscreens due to its ability to block UV rays.

Studies have found adenosine may also help with wound healing.

In skincare products, Adenosine is usually derived from yeast.

One study found topical low molecular weight hyaluronic acid may be considered for the treatment of rosacea in the adult population. However, we always recommend speaking with a professional about your skin concerns.

Hyaluronic acids are a humectant. This means they draw moisture from the air. Hyaluronic acids help moisturize, soothe, and protect the skin.

Read more about other common forms of hyaluronic acid:

The 20 stands for the number of ethylene oxide used to create this ingredient.

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.

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.

Palmitoyl Tripeptide-1 can help reduce wrinkles and make the skin look more youthful.

Read more about other common types of peptides here:

As an antioxidant, it helps fight free-radical molecules. Free-radical molecules are capable of damaging our cells and other genetic material. Thus, antioxidants may reduce the signs of aging.

This ingredient is oil-soluble.

This ingredient has many benefits. These benefits include boosting collagen production, fighting inflammation, and reversing UV damage.

By preventing our bodies from producing interleukins, Palmitoyl Tetrapeptide-7 helps fight inflammation. An interleukin is a chemical that signals to the body to produce an inflammatory response. Interleukin production is accelerated by UV radiation.

Palmitoyl Tetrapeptide-7 tells our body to create more collagen. Collagen is a protein that makes connective tissue. Boosting collagen production leads to a healthier skin barrier. Having a healthy skin barrier means having firm and hydrated skin.

Read more about other common types of peptides here:

If you spot Citric Acid near the end of an ingredient list, it's likely there as a pH adjuster rather than an active ingredient.

Read more about some other popular AHA's here:

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.