Neutrogena Hydro Boost Ultra Hydrating Serum Versus Medik8 Hydr8 B5 Intense

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.

This ingredient is an amino acid that helps build proteins and moisturizes skin. It is already present in our skin as our bodies produce them naturally.

Glycine already plays a role in helping keep our skin moisturized as amino acids transport moisture throughout our skin.

Alanine is an amino acid and is already found in the human body. Our skin uses alanine to build collagen, elastin, and keratin.

Threonine is an amino-acid. It helps hydrate the skin and has antioxidant benefits.

Our skin uses threonine for creating collagen and elastin. Humans are not able to create threonine and must get it through eating foods such as fish, lentils, poultry, sesame seeds, and more.

Arginine is an amino acid that is important for human development. Your body uses is it to produce hair keratin and skin collagen.

As a cosmetic ingredient, Arginine has antioxidant properties and can also help repair damaged skin. This ingredient is derived either synthetically or from animals.

Proline is an amino-acid. It helps moisturize the skin and plays an important role in creating proteins.

Our skin uses proline as one of the building blocks for producing collagen.

Lysine HCl is an alpha amino acid salt.

Our skin uses amino acids as a precursor for building protein, and therefore keratins, collagen and elastin.

Glutamic Acid is an amino acid that is found in all living organisms. Our bodies use this to help nerve cells in the brain communicate with other cells.

In cosmetics, glutamic acid is a famous humectant. It draws water from the air to your skin, keeping your skin hydrated (like hyaluronic acid).

Sodium PCA is the sodium salt of pyroglutamic acid. It is naturally occurring in our skin's natural moisturizing factors where it works to maintain hydration.

The PCA stands for pyrrolidone carboxylic acid, a natural amino acid derivative.

PCA is derived from amino acids and is naturally found in our skin's barrier.

As a humectant, PCA helps draw and hold moisture to the skin. Studies show it is effective at helping the skin stay hydrated long-term.

Urea is also called carbamide and is the diamide of carbonic acid. In cosmetics, urea is used to hydrate the skin. It also provides exfoliation in higher concentrations.

As a humectant, urea helps draw moisture from the air and from deep within the skin. This helps hydrate your skin. Studies show urea is an effective moisturizer for dry skin conditions. 40% urea is typical in medications for treating eczema and other skin conditions.

Citric Acid is an AHA derived from citrus fruits (think oranges, lemons, and limes!).

As an AHA, Citric Acid removes the top layer of skin cells from the newer layer of skin underneath. This helps skin to remove dark spots and even out skin tone.

Allantoin plays a role in soothing and moisturizing the skin. Because of this, it is often added to products with strong active ingredients.

Some studies have shown this ingredient can promote wound healing with higher concentrations.

Trehalose is a disaccharide made of two glucose molecules (glucose is sugar!). Trehalose is used to help moisturize skin. It also has antioxidant properties.

As a humectant, trehalose helps draw moisture from the air to your skin. This helps keep your skin hydrated.

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.