Skin science article
Medik8 Liquid Peptides Versus Medik8 Niacinamide Peptides
Medik8 Liquid Peptides Versus Medik8 Niacinamide Peptides This anti-aging serum is formulated around Carnosine and Palmitoyl Tripeptide-5 to soften the look of wrinkles and refine skin texture. This smoothing serum is formulated around Niacinamide and Zinc PCA
Medik8 Liquid Peptides Versus Medik8 Niacinamide Peptides
This anti-aging serum is formulated around Carnosine and Palmitoyl Tripeptide-5 to soften the look of wrinkles and refine skin texture.
This smoothing serum is formulated around Niacinamide and Zinc PCA to refine skin texture and balance excess oil.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Glycerin
Butylene Glycol
Inulin
Sodium Hyaluronate
Panthenol
Alpha-Glucan Oligosaccharide
Carnosine
Carbomer
Polysorbate 20
Caprylyl Glycol
Phenoxyethanol
Hydroxypropyl Cyclodextrin
Dunaliella Salina Extract
Ethylhexylglycerin
Citric Acid
Palmitoyl Tripeptide-5
Sodium Benzoate
Acetyl Hexapeptide-8
Tetrapeptide-21
Pentapeptide-18
Palmitoyl Tripeptide-1
Pantolactone
Palmitoyl Tripeptide-38
Palmitoyl Tetrapeptide-7
Glyceryl Caprylate
Lactic Acid/Glycolic Acid Copolymer
Polyvinyl Alcohol
Phenylpropanol
Copper Palmitoyl Heptapeptide-14
Heptapeptide-15 Palmitate
Potassium Sorbate
Xanthan Gum
Water, Glycerin, Butylene Glycol, Inulin, Sodium Hyaluronate, Panthenol, Alpha-Glucan Oligosaccharide, Carnosine, Carbomer, Polysorbate 20, Caprylyl Glycol, Phenoxyethanol, Hydroxypropyl Cyclodextrin, Dunaliella Salina Extract, Ethylhexylglycerin, Citric Acid, Palmitoyl Tripeptide-5, Sodium Benzoate, Acetyl Hexapeptide-8, Tetrapeptide-21, Pentapeptide-18, Palmitoyl Tripeptide-1, Pantolactone, Palmitoyl Tripeptide-38, Palmitoyl Tetrapeptide-7, Glyceryl Caprylate, Lactic Acid/Glycolic Acid Copolymer, Polyvinyl Alcohol, Phenylpropanol, Copper Palmitoyl Heptapeptide-14, Heptapeptide-15 Palmitate, Potassium Sorbate, Xanthan Gum
Niacinamide
Caprylic/Capric Triglyceride
Acetyl Glucosamine
Glyceryl Stearate Citrate
Dimethicone
Zinc PCA
Palmitoyl Tetrapeptide-10
Polyglyceryl-3 Stearate
Hydroxyacetophenone
Crambe Abyssinica Seed Oil
Hydrogenated Lecithin
Behenyl Alcohol
Cetearyl Alcohol
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Disodium EDTA
Cetyl Palmitate
Sorbitan Stearate
Polysorbate 80
Polysorbate 60
Sorbitan Isostearate
Tocopherol
Water, Niacinamide, Caprylic/Capric Triglyceride, Acetyl Glucosamine, Glyceryl Stearate Citrate, Glycerin, Dimethicone, Zinc PCA, Palmitoyl Tetrapeptide-10, Sodium Hyaluronate, Phenoxyethanol, Polyglyceryl-3 Stearate, Hydroxyacetophenone, Crambe Abyssinica Seed Oil, Hydrogenated Lecithin, Behenyl Alcohol, Cetearyl Alcohol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Disodium EDTA, Xanthan Gum, Cetyl Palmitate, Ethylhexylglycerin, Carnosine, Sorbitan Stearate, Polysorbate 80, Polysorbate 60, Sorbitan Isostearate, Sodium Benzoate, Citric Acid, Tocopherol
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.
Carnosine is a dipeptide made from two amino acids.
This ingredient helps:
Glycation is the process of sugars binding to and damaging proteins. Too much sugar in our skin can lead to damaged collagen, contributing to factors of aging.
Carnosine is water-soluble and is not able to travel deeper layers of skin. This leads to some doubt about whether it can boost collagen in skin, since collagen is located in the deeper layers of skin.
Fun fact: Carnosine can be naturally found in our muscles and brain.
Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.
Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.
However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.
Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.
In skincare formulas, citric acid can:
While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.
Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.
Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.
However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.
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.
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.
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!
Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.
Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.