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.

Though Caprylyl Glycol is an alcohol derived from fatty acids, it is not the kind that can dry out skin.

This ingredient is also used as a preservative to extend the life of products. It has slight antimicrobial properties.

While studying wound healing, researchers noticed GHK-Cu stimulated hair follicle enlargement and growth by keeping hair in its active growth phase longer. This has made it a promising ingredient for hair regrowth treatments.

Some people have reported increased facial hair. While GHK-Cu can make your hair follicles bigger, it usually doesn’t turn soft, barely-visible facial hairs into thick, dark ones.

Anecdotal reports suggest that overusing copper peptides might lead to premature aging due to excess free copper or enzyme imbalances. This claim isn’t backed by large-scale studies.

Unfortunately, there are limited human studies for this ingredient. While early results are promising, many studies are either small, in-vitro, or not rigorously controlled.

For example, there is a 1998 study that explored the effects of copper tripeptide, vitamin C, tretinoin, and melatonin on skin repair and collagen synthesis.

After one month, increased procollagen production was seen in 7 out of 10 participants using copper tripeptide (more than those using vitamin C, melatonin, or tretinoin.

While the study was exploratory, it offers early evidence that copper tripeptide may support collagen production. Larger, well-designed trials are still needed to confirm its potential and understand individual responses.

Read more about other common types of peptides here:

Dipropylene glycol is technically an alcohol, but it belongs to the glycol family (often considered part of the ‘good’ alcohols). This means it is hydrating and gentle on skin unlike drying solvent alcohols like denatured alcohol.

As a masking agent, Dipropylene Glycol can be used to cover the smell of other ingredients. However, it does not have a scent.

Studies show Dipropylene Glycol is considered safe to use in skincare.

Disodium EDTA is a salt of edetic acid and is found to be safe in cosmetic ingredients.

Glucose is hydrating due to its humectant property. As a humectant, glucose draws moisture from the air and from deeper levels in the skin.

Our skin contains many sugars that act as prebiotics and help strengthen our natural microbiome. Having a healthy microbiome helps protect our skin from harmful bacteria and other contaminants.

Studies show glucose may help with fading discoloration and pigmentation. This is because our skin metabolizes glucose into lactic acid. Lactic acid is an AHA that helps exfoliate the top layer of skin.

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.

What makes hyaluronic acid so hydrating? It has the capacity to bind or hold large amounts of water.

Fun fact: It is already naturally found in our bodies, such as the fluids of our eyes and our joints.

Studies find this ingredient to have anti-inflammatory and anti-microbial properties. This can help speed up wound-healing.

Hyaluronic acid can be irritating if the molecule has a low-molecular weight, or if the molecules are small.

One study found low-molecular weight hyaluronic acid to be pro-inflammatory, meaning some people may experience irritation. This is because our bodies use hyaluronic acid in the wound-healing process to signal to our bodies, via irritation, that something needs healing.

The same study found high-molecular weight hyaluronic acid to be anti-inflammatory.

These are some other common types of Hyaluronic Acid:

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:

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.

This ingredients 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.

Thus, Matrixyl may help improve the look of wrinkles.

Read more about other common types of peptides here:

By boosting collagen production, this ingredient supports a stronger skin barrier and helps reduce the appearance of wrinkles.

You'll most likely see this ingredient paired with Palmitoyl Tetrapeptide-7 in the well-known Matrixyl 3000 complex. While results from in-house testing should be viewed cautiously, this peptide duo is among the most studied and widely used in modern skincare.

Due to its palmitic acid base, this ingredient may not be safe for Malassezia folliculitis.

Read more about other common types of peptides here:

Due to its palmitic acid base, this peptide may not be fungal-acne safe.

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.

Polyglyceryl-10 Laurate may not be fungal acne safe.

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

These are some other common types of Hyaluronic Acid:

GHK is also unique because is also acts as a carrier peptide. It binds to and transports copper ions (forming the complex GHK-Cu). This form has been studied for decades and is known to stimulate wound healing, boost antioxidant defenses, and promote collagen/elastin synthesis.

In-vitro studies show both GHK and GHK-CU increase fibroblast activity that enhances the production of collagen, elastin, fibronectin, and other extracellular matrix components.

Both of these compounds also help balance enzymes that control collagen breakdown.

Human studies (in-vivo) using GHK-Cu creams have reported visible improvements to skin density, elasticity, and wrinkle depth after several weeks of use.

A small clinical study also found topical collagen tripeptide improved wrinkle appearance and skin elasticity in women after four weeks.

While these results are promising, most research is based on GHK-Cu or its derivatives rather than Tripeptide-1 alone (Palmitoyl Tripeptide-1 is a famous derivative of GHK). However, the consensus still supports GHK as a potent skin-signaling molecule that can encourage regeneration and maintain youthful looking skin.

Fun fact: GHK is a naturally occurring fragment of type 1 collagen that can be found in human plasma, saliva, and urine.

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!

The prebiotic property of xylitol may also help reinforce our skin's natural microbiome. Having a healthy microbiome prevents infection by bad bacteria and helps with hydration.

As a humectant, Xylitol helps draw moisture from both the air and from deeper skin layers. This helps keep skin hydrated.

Xylitol is a sugar alcohol and commonly used as a sugar substitute. It is naturally occurring in plants such as strawberries and pumpkin.

This ingredient is most commonly found in a popular trio called Aquaxyl. Aquaxyl is made up of anhydroxylitol(24 - 34%), xylitylglucoside (35 - 50%), and xylitol (5 - 15%).

According to a manufacturer, Aquaxyl is known for a 3-D hydration concept and an anti-dehydration shield to reinforce the outer layer of skin.