COSRX Advanced Snail Hydrogel Eye Patch Versus COSRX Advanced Snail Peptide Eye Cream

Some studies suggest betaine may support making skin tone more even.

Fun fact: Betaine naturally exists in the skin and the body. In cosmetic products, it can be either plant-derived (most commonly from sugar beets) or synthetically produced for consistency and stability.

Betaine is also known as trimethylglycine.

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.

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

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.

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.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!