ZO Skin Health 10% Vitamin C Self-Activating Versus IMAGE skincare Vital C Hydrating Anti-Aging Serum

ZO Skin Health 10% Vitamin C Self-Activating Versus IMAGE skincare Vital C Hydrating Anti-Aging Serum

This brightening serum is formulated around Ascorbic Acid and Tetrahexyldecyl Ascorbate to brighten dull-looking skin and fade the look of dark spots.

This hydrating serum is formulated around Aloe Barbadensis Leaf Juice and Magnesium Ascorbyl Phosphate to hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Cyclopentasiloxane

Dimethicone Crosspolymer

Ascorbic Acid

Dimethicone

Citrus Aurantium Amara Peel Oil

Squalane

Tetrahexyldecyl Ascorbate

Tocopheryl Acetate

Ubiquinone

Limonene

Citral

Phenoxyethanol

Cyclopentasiloxane, Dimethicone Crosspolymer, Ascorbic Acid, Dimethicone, Citrus Aurantium Amara Peel Oil, Squalane, Tetrahexyldecyl Ascorbate, Tocopheryl Acetate, Ubiquinone, Limonene, Citral, Phenoxyethanol

Aloe Barbadensis Leaf Juice

Water

Glycerin

Citrus Aurantium Dulcis Oil

Caprylic/Capric Triglyceride

C12-15 Alkyl Benzoate

Cetearyl Olivate

Sorbitan Olivate

Imperata Cylindrica Root Extract

Magnesium Ascorbyl Phosphate

PPG-12/Smdi Copolymer

Glyceryl Stearate

PEG-100 Stearate

Cetyl Alcohol

Di-PPG-2 Myreth-10 Adipate

Stearic Acid

Ethylhexyl Methoxycinnamate

Panthenol

Prunus Amygdalus Dulcis Oil

Xanthan Gum

Caprylyl Glycol

Butylene Glycol

Glycine Soja Sterols

Linoleic Acid

Phospholipids

Simmondsia Chinensis Seed Oil

Squalene

Propylene Glycol

Ethylhexylglycerin

Glucosamine Hcl

Hexylene Glycol

Linoleamidopropyl Pg-Dimonium Chloride Phosphate

PEG-8

Pisum Sativum Extract

Citrus Nobilis Peel Oil

Dipotassium Glycyrrhizate

Phyllanthus Emblica Fruit Extract

Stearyl Glycyrrhetinate

Bambusa Vulgaris Leaf/Stem Extract

Tocopherol

Magnesium Aluminum Silicate

Olea Europaea Leaf Extract

Disodium EDTA

Eugenia Caryophyllus Leaf Oil

Yeast Polysaccharides

Sodium Hyaluronate

Glyceryl Polymethacrylate

Carbomer

Eugenol

Ascorbyl Palmitate

Citric Acid

Benzoic Acid

Camellia Sinensis Leaf Extract

Sodium Lactate

Polysorbate 20

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Spiraea Ulmaria Flower Extract

Taurine

Corallina Officinalis Extract

Vitis Vinifera Seed Extract

Centella Asiatica Flower/Leaf/Stem Extract

Centella Asiatica Extract

Potassium Sorbate

BHT

Acetyl Hexapeptide-8

Darutoside

Palmitoyl Pentapeptide-4

Arginine

Leucine

Lysine

Sodium Benzoate

Valine

Palmitoyl Tripeptide-1

Aloe Barbadensis Leaf Juice, Water, Glycerin, Citrus Aurantium Dulcis Oil, Caprylic/Capric Triglyceride, Limonene, C12-15 Alkyl Benzoate, Cetearyl Olivate, Sorbitan Olivate, Imperata Cylindrica Root Extract, Magnesium Ascorbyl Phosphate, PPG-12/Smdi Copolymer, Tetrahexyldecyl Ascorbate, Glyceryl Stearate, PEG-100 Stearate, Cetyl Alcohol, Dimethicone, Di-PPG-2 Myreth-10 Adipate, Stearic Acid, Phenoxyethanol, Ethylhexyl Methoxycinnamate, Panthenol, Prunus Amygdalus Dulcis Oil, Xanthan Gum, Caprylyl Glycol, Butylene Glycol, Tocopheryl Acetate, Glycine Soja Sterols, Linoleic Acid, Phospholipids, Simmondsia Chinensis Seed Oil, Squalene, Propylene Glycol, Ethylhexylglycerin, Glucosamine Hcl, Hexylene Glycol, Linoleamidopropyl Pg-Dimonium Chloride Phosphate, PEG-8, Pisum Sativum Extract, Citrus Nobilis Peel Oil, Dipotassium Glycyrrhizate, Phyllanthus Emblica Fruit Extract, Stearyl Glycyrrhetinate, Bambusa Vulgaris Leaf/Stem Extract, Tocopherol, Magnesium Aluminum Silicate, Olea Europaea Leaf Extract, Disodium EDTA, Eugenia Caryophyllus Leaf Oil, Yeast Polysaccharides, Sodium Hyaluronate, Glyceryl Polymethacrylate, Carbomer, Eugenol, Ascorbyl Palmitate, Citric Acid, Benzoic Acid, Camellia Sinensis Leaf Extract, Ascorbic Acid, Sodium Lactate, Polysorbate 20, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Spiraea Ulmaria Flower Extract, Taurine, Corallina Officinalis Extract, Vitis Vinifera Seed Extract, Centella Asiatica Flower/Leaf/Stem Extract, Centella Asiatica Extract, Potassium Sorbate, BHT, Acetyl Hexapeptide-8, Darutoside, Palmitoyl Pentapeptide-4, Arginine, Leucine, Lysine, Sodium Benzoate, Valine, Palmitoyl Tripeptide-1

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Ascorbic Acid is is pure Vitamin C and is the biologically active form used directly by skin.

Not only is vitamin C great for your overall health and immune system, but it also has plenty of benefits for your skin. It is best supported by academic literature for:

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.

Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.

What it does:

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

Limonene is a fragrance that adds scent and taste to a formulation.

It's found in the peel oil of citrus fruits and other plants such as lavender and eucalyptus. The scent of limonene is generally described as "sweet citrus".

Limonene acts as an antioxidant, meaning it helps neutralize free radicals.

When exposed to air, oxidized limonene may sensitize the skin. Because of this, limonene is often avoided by people with sensitive skin.

The term '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.

Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).

It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

Tetrahexyldecyl Ascorbate (THD) is a stable and oil-soluble form of Vitamin C.

THD is special in that it has the ability to travel deeper into skin than traditional ascorbic acid while maintaining the same skin benefits (double win!).

Because it’s oil-soluble, THD dives deep into your skin’s fatty layers (think ceramides and cholesterol) to fight off the kind of free radicals that mess with your skin barrier. This makes it a great pair with water-based vitamin C (ascorbic acid) that mainly works on the surface.

Even at just 0.1%, THD is already showing great antioxidant activity. When used up to 2%, it helps keep your skin happy and calm, especially when it’s stressed from pollution or sun.

Want to fade dark spots or tackle hyperpigmentation? You’ll want 5% or more. Pairing it with brightening buddies like niacinamide or licorice root gives even better results. One study even used 30% THD with other brighteners and saw real results on stubborn discoloration, even in melasma-prone skin.

A note on THD: It’s has a slightly silky, oily texture and usually shows up colorless or pale yellow (though the exact shade can vary by supplier).

While you can sneak it into water-based formulas, it really shines when paired with silicones or oils, which help your skin soak it up better.

THD is pretty stable, but it’s still vulnerable to degradation like ascorbic acid. Too much light or heat (above 113°F / 45°C) can break it down over time. Go for dark and opaque packaging that keeps it safe and shady!

Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.

Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.

It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.

One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.

Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.

Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.

The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.

Most leave-on skincare keeps it at the lower end, often between 0.5-1%.

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