Endocare C Proteoglycans

In a formula, it acts as a humectant and barrier-supporting soother and the research backs this up as well.

A 2025 systematic review of human clinical trials found that snail-derived ingredients improved signs of aging, increased skin hydration, decreased transepidermal water loss, and improved healing after radiation therapy/fractional laser treatment.

Lab studies have also shown the secretion promotes the proliferation, migration, and survival of the cells that rebuild skin (keratinocytes and dermal fibroblasts).

There's also a placebo-controlled study where a serum containing it helped with mask-related acne.

Overall, this is a gentle, water-based multitasker that works great for hydrating and supporting the skin barrier. However, please see the section below if you have dust mite or shellfish allergies.

You'll see snail filtrate listed at very different percentages depending on the product. Some Korean serums list it near the top of the ingredients at 90% or more while other products use just a few percent.

This doesn't mean the high-percentage ones are far stronger. Raw snail filtrate is mostly water to begin with so using a lot of it isn't the same thing as using a lot of the active ingredients.

Other products use a concentrated version so a small amount goes a long way. Either approach can work well. Just know the percentage on the label isn't a reliable way to judge how effective a snail product will be.

Being cruelty-free means a brand does not experiment on animals. If you're worried about the well-being of the snails, we recommend looking more into the company of the product. Many brands claim to have developed humane methods to collect snail mucin.

There is much debate on this subject. On one hand, this ingredient comes from an animal. On the other hand, many will argue the ingredient is naturally secreted (like a natural by-product) and therefore vegan. If you have reservations, you can look into Galactomyces Ferment Filtrate or Centella Asiatica Extract as alternatives.

This ingredient is fungal acne safe. Its core composition lacks the fatty acid/ester triggers that Malassezia depends on.

True allergy to Snail Secretion Filtrate is uncommon and most documented cases are linked to a dust mite allergy.

Snail proteins (including Tropomyosin) are similar enough to dust mite proteins that the immune system can confuse them.

In most documented cases, the dust mite was the original trigger and tropomyosin turned out to be only a minor player in some studies (so this has not been fully confirmed).

Another thing to know is that nearly all the evidence comes from eating snails or inhaling the protein and not from cosmetics.

However, the allergenic proteins can survive filtration into a finished product; a topical reaction is biologically plausible but there's little published evidence of it actually happening.

People who are allergic to dust mites (or sometimes shellfish) are the most likely to react.

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.

3-O-Ethyl Ascorbic Acid interferes with the process of skin darkening, helping to reduce hyperpigmentation. It also encourages the skin to produce more collagen.

Once applied, 3-O-Ethyl Ascorbic Acid is converted to Vitamin C deeper in the skin's layers. This process is slow but makes this ingredient more tolerable for skin.

The optimum pH range for this ingredient is 4 - 5.5

Topical vitamin C has been shown to help neutralize oxidative stress from UV and pollution, helping to improve photoaging and hyperpigmentation when used consistently.

One clinical study found that using 5% topical vitamin C for six months improved signs of photodamaged skin, both on the surface and in the deeper structural layers of the skin.

While vitamin C doesn’t replace sunscreen, studies show it can boost photoprotection when combined with Vitamin E and ferulic acid. These two ingredients help improve stability and protective effects.

The big downside of this ingredient is formulation difficulty. Vitamin C is prone to oxidation and doesn't penetrate the skin unless formulated correctly. Research found that vitamin C absorbs into the skin best at a low pH (< 3.5) with about 20% being the upper limit for effective absorption.

Skin levels can saturate after repeated application; this means your skin won’t keep absorbing more once it’s full of vitamin C. This is why more isn’t always better with vitamin C and why very high concentrations don’t necessarily give extra benefits.

Ascorbic acid generally works well with many skincare ingredients but can be irritating when combined with other active ingredients. Strong oxidizing acne treatments like benzoyl peroxide can reduce the effectiveness of vitamin C if they are used at the same time; they are often recommended for use at different times of day.

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.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

Tocopheryl Acetate is commonly found in both skincare and dietary supplements.

The way it works is worth understanding; benzoic acid works when the formula is acidic. It is able to sneak into a microbe's cell and mess up how it functions to stop it from growing in an acidic product.

However, the acid switches to an inactive form and stops working if a product isn't acidic enough (above ~5 pH). This is why you'll often see it in low pH products or teamed up with other preservatives to cover the gap.

Safety wise, it's one of the better studied preservatives out there.

The Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe for use in cosmetic formulations at concentrations up to 5%.

A large international review found this ingredient had no effects on the human body and had low irritation potential.

Just so you know, real world use is usually much lower than the 5% ceiling (usually 1% of less).

The EU caps it at 2.5% in rinse-off products, 1.7% in oral care, and 0.5% in leave-on products.

One thing worth mentioning (it's nothing to worry about): some people get a little stinging or flushing where they apply it. This isn't a true allergy; it's a temporary and harmless reaction. This is the same kind of mild tingle you might notice from sorbic acid.

It is effective at low concentrations (<0.6%). Clinical studies have found it to be non-irritating, non-sensitizing, and non-photosensitizing.

For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.

The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.

For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.

One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.

Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.

Parfum can also be used to mask or cover an unpleasant scent.

The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.