Nature Republic The First Peptide Boosting Serum Versus Peach & Lily Copper Peptide Pro Firming Serum

Studies have found adenosine may also help with wound healing.

In skincare products, Adenosine is usually derived from yeast.

Arginine isn't fungal acne safe when used in the presence of other lipids (fats, fatty acids, oils, esters, etc). Oils and fats occur naturally within the skin, so take caution when using Arginine if you're prone to fungal acne.

Fun fact: Betaine is naturally created in the skin and body. The kind found within cosmetic products can be either plant-derived or synthetic.

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.

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:

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.

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:

Fun fact: Methionine can be found in meat, fish, and dairy. It cannot be naturally produce and requires dietary intake.

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:

Serine is a non-essential amino acid, meaning we don't need to obtain it from eating foods.

Sodium Hyaluronate is naturally occurring in our bodies and is mostly found in eye fluid and joints.

These are some other common types of Hyaluronic Acid:

Squalane comes from squalene, which occurs naturally within the sebum of our skin. It is one of the oils our skin produces to keep itself hydrated. Squalane is the hydrogenated version of squalene and has a longer shelf life.

Research shows that squalane is non-irritating (even at 100% concentration).

In general, it's a fantastic ingredient. It does a great job at hydrating the skin, and it's suitable for those with sensitive skin.

The source of squalane may impact malassezia / fungal acne. This is because olive oil derived squalane can contain impurities such as fatty acids and plant waxes. Sugarcane derived squalane is recommended for anyone with malassezia concerns.

Is squalane vegan?

This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.

Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.

Read more about squalene with an "e".

Is squalane an oil?

Squalane is often called an oil, but it’s technically not; it’s a hydrocarbon, meaning it’s only made of carbon and hydrogen, unlike true oils which are triglycerides made of fatty acids and glycerol.

The term “oil-free” isn’t regulated, so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.

While some people avoid oils thinking they cause breakouts, the right kind of oil (or oil-like ingredient like squalane) can actually help balance and hydrate your skin. It’s worth testing out simple oils or squalane to see what works best for your skin.

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!