Medik8 Hydr8 B5 Intense Versus Paula's Choice Calm Repairing Serum

Medik8 Hydr8 B5 Intense Versus Paula's Choice Calm Repairing Serum

This hydrating serum is formulated around Panthenol and Sodium Hyaluronate to hydrate skin and strengthen the skin barrier.

This calming serum is formulated around Sodium Hyaluronate and Ceramide NP to calm redness and strengthen the skin barrier.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Panthenol

Glyceryl Glucoside

Propylene Glycol

Sodium Hyaluronate

Glycerin

Sodium PCA

Amelanchier Alnifolia Fruit Extract

Urea

Calcium Pantothenate

Trehalose

Taurine

Creatine

Diglycerin

Acetyl Glucosamine

Daucus Carota Sativa Juice

Glycine Soja Seed Extract

Lysine Hcl

Alanine

Arginine

Histidine Hcl

Biosaccharide Gum-1

Phenoxyethanol

Serine

Allantoin

Proline

Lactic Acid

Ethylhexylglycerin

Hydroxyacetophenone

Hydrolyzed Wheat Protein

Lysine

PCA

Sorbitol

Glutamic Acid

Threonine

Valine

Leucine

Glycine

Isoleucine

Phenylalanine

Potassium Sorbate

Sodium Benzoate

Citric Acid

Water, Panthenol, Glyceryl Glucoside, Propylene Glycol, Sodium Hyaluronate, Glycerin, Sodium PCA, Amelanchier Alnifolia Fruit Extract, Urea, Calcium Pantothenate, Trehalose, Taurine, Creatine, Diglycerin, Acetyl Glucosamine, Daucus Carota Sativa Juice, Glycine Soja Seed Extract, Lysine Hcl, Alanine, Arginine, Histidine Hcl, Biosaccharide Gum-1, Phenoxyethanol, Serine, Allantoin, Proline, Lactic Acid, Ethylhexylglycerin, Hydroxyacetophenone, Hydrolyzed Wheat Protein, Lysine, PCA, Sorbitol, Glutamic Acid, Threonine, Valine, Leucine, Glycine, Isoleucine, Phenylalanine, Potassium Sorbate, Sodium Benzoate, Citric Acid

Sodium Lauroyl Lactylate

Polysorbate 20

Caprylic/Capric Triglyceride

PEG/PPG-14/4 Dimethicone

Xanthan Gum

Disodium EDTA

Sodium Cocoyl Amino Acids

Ceramide NP

Epilobium Angustifolium Extract

Ceramide AP

Cholesterol

Phytosphingosine

Beta-Glucan

Sarcosine

Carbomer

Chrysanthemum Parthenium Flower Extract

Sea Whip Extract

Hyaluronic Acid

Glycyrrhiza Glabra Root Extract

Ceramide EOP

Magnesium Aspartate

Potassium Aspartate

Ubiquinone

1,2-Hexanediol

Caprylyl Glycol

Leuconostoc/Radish Root Ferment Filtrate

Calcium Chloride

Tocopherol

Sodium Metabisulfite

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

Water, Glycerin, Sodium Lauroyl Lactylate, Sodium Hyaluronate, Polysorbate 20, Caprylic/Capric Triglyceride, PEG/PPG-14/4 Dimethicone, Xanthan Gum, Disodium EDTA, Sodium Cocoyl Amino Acids, Ceramide NP, Ethylhexylglycerin, Epilobium Angustifolium Extract, Ceramide AP, Cholesterol, Phytosphingosine, Beta-Glucan, Sarcosine, Carbomer, Chrysanthemum Parthenium Flower Extract, Sea Whip Extract, Glycine Soja Seed Extract, Hyaluronic Acid, Glycyrrhiza Glabra Root Extract, Ceramide EOP, Magnesium Aspartate, Potassium Aspartate, Ubiquinone, Phenoxyethanol, 1,2-Hexanediol, Caprylyl Glycol, Leuconostoc/Radish Root Ferment Filtrate, Calcium Chloride, Propylene Glycol, Tocopherol, Sodium Metabisulfite, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Sodium Benzoate, Potassium Sorbate

Reviews

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:

The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.

Topically, glycerin does several things at once:

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.

Glycine Soja Seed Extract comes from the seed of the wild soybean plant. Wild soybean extract contains fatty acids (linoleic, oleic, linolenic), vitamin E, and antioxidants.

The wild soybean contains soyasaponins, a bioactive compound. Soyasaponins have inflammatory, antimutagenic, anticarcinogenic, antimicrobial properties. Soyasaponin has also been found to inhibit the melanin-creation process.

Two powerful components found in the wild soybean include genistein and diadzein. These two isoflavones are potent antioxidants with anti-inflammatory properties. Genistein in particular has been found to prevent redness caused by UV exposure.

One study from South Korea found wild soybean extract to help promote hair growth at the cellular level.

The wild soybean plant is a cousin to the famous soybean that gives us tofu, soy milk, and soy sauce.

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.

Potassium Sorbate is a preservative used to prevent yeast and mold in products. It is commonly found in both cosmetic and food products.

This ingredient comes from potassium salt derived from sorbic acid. Sorbic acid is a natural antibiotic and effective against fungus.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

Propylene Glycol is a synthetic, colorless, odorless liquid that has been a staple in cosmetics for decades. It is a skin conditioning agent, humectant, and solvent.

As a humectant, it draw water to the skin to reduce flaking and restore suppleness. It's also a solvent that helps dissolve other actives and keeps formulas stable across temperature changes.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

Sodium Hyaluronate is the salt form of hyaluronic acid. It is a long sugar chain that is naturally found in your skin, joints, and connective tissue that maintains hydration and elasticity.

In skincare, it works as a humectant. It pulls water from the environment and deeper layers of skin and binds it to the surface.

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.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

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!

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