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.

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.

Collagen extract is derived from parts of animals. It has skin conditioning properties and is mostly comprised of glycine, proline, and hydroxypoline. These are amino acids.

While our skin does have collagen, this ingredient is not used by the skin for anti-aging. Applying collagen topically has not been linked to helping with collagen loss in skin. All the benefits of collagen are related to hydration.

Cysteine is an amino acid found in our bodies. It becomes an antioxidant when converted into gluthatione.

Once it becomes gluthatione, it prevents oxidative damage to parts of our cell. Gluthatione has also been shown to protect our skin from UV-B induced damage.

Dipropylene Glycol is a synthetically created humectant, stabilizer, and solvent.

This ingredient helps:

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.

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.

Hexapeptide-9 is a peptide.

Hyaluronic acid is naturally found in healthy skin. It is a humectant, meaning it draws moisture to your skin.

This ingredient helps hydrate, soothe, and protect the skin.

Hydrolyzed Hyaluronic Acid is a form of hyaluronic acid. It is created by the hydrolysis of hyaluronic acid with a high molecular weight. Once created, Hydrolyzed Hyaluronic Acid has a low molecular weight.

Low molecular weight HA has been shown to hydrate and increase elasticity of the skin. Increasing elasticity is also associated with reduction of wrinkle depth.

This form of hyaluronic acid is produced through fermentation.

According to a manufacturer, it has a positive charge by ionic binding to help moisturize and give hair a smooth feel. This is why you'll find this ingredient in shampoos and body washes.

Methionine is an essential amino acid. It is a conditioning agent and commonly found in both skin and hair products.

This amino acid is a precursor to glutathione, a powerful antioxidant.

Nonapeptide-1 is created from amino acids including arginine and lysine.

It has antioxidant and antimicrobial properties.

You might know this ingredients as Matrixyl, a famous peptide.

Peptides are building blocks for protein. Palmitoyl Pentapeptide-4 consists of five amino acids. These amino acids include: 2 lysines, 2 threonines, and serine

Palmitoyl Tripeptide-1 is also known as pal-GHK. It is made up of 3 amino acids and palmitic acid, a fatty acid that helps it absorb into skin more easily.

This peptide is as a signal peptide, meaning it tells the skin to produce more collagen. Collagen is the key protein that helps form the skin's structure and keep it plump, firm, and hydrated.

Potassium hyaluronate (PH) is a salt form of hyaluronic acid and has similar skin hydrating benefits.

Similar to hyaluronic acid, PH is able to draw and hold moisture to your skin. This helps keep skin soft and hydrated.

Serine is an amino acid naturally found in our body. Our bodies use amino acids to create protein.

Amino-acids help give keep our skin hydrated. They play an important role in the skin barrier, which keeps the skin plump and firm.

Sodium Acetylated Hyaluronate is a type of Hyaluronic Acid.

Hyaluronic Acids help moisturize, soothe, and protect the skin.

Sodium Hyaluronate is hyaluronic acid's salt form. It is commonly derived from the sodium salt of hyaluronic acid.

Like hyaluronic acid, it is great at holding water and acts as a humectant. This makes it a great skin hydrating ingredient.

Sodium Hyaluronate Crosspolymer is a type of hyaluronic acid. In fact, it is modified version of hyaluronic acid.

The structure of Sodium Hyaluronate Crosspolymer allows it to stay in the skin's top layer for a longer period of time. This allows for even more hydration and humectant action than hyaluronic acid.

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.