Skin science article
Alastin Restorative Skin Complex Versus Medik8 Liquid Peptides
Alastin Restorative Skin Complex Versus Medik8 Liquid Peptides This anti-aging treatment is formulated around Niacinamide and Palmitoyl Hexapeptide-12 to soften the look of wrinkles and strengthen the skin barrier. This anti-aging serum is formulated around Ca
Alastin Restorative Skin Complex Versus Medik8 Liquid Peptides
This anti-aging treatment is formulated around Niacinamide and Palmitoyl Hexapeptide-12 to soften the look of wrinkles and strengthen the skin barrier.
This anti-aging serum is formulated around Carnosine and Palmitoyl Tripeptide-5 to soften the look of wrinkles and refine skin texture.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Glycerin
Niacinamide
Isopropyl Palmitate
Polyacrylate-13
Butylene Glycol
Palmitoyl Hexapeptide-12
Palmitoyl Tripeptide-1
Palmitoyl Tripeptide-5
Palmitoyl Dipeptide-5 Diaminobutyroyl Hydroxythreonine
Palmitoyl Dipeptide-5 Diaminohydroxybutyrate
Acetyl Hexapeptide-38
Octapeptide-45
Swertia Chirata Extract
Magnolol
Ornithine
Ceramide AP
Ceramide NP
Ergothioneine
Dunaliella Salina Extract
Phytosterols
Phospholipids
Glycolipids
Tremella Fuciformis Sporocarp Extract
Caprylic/Capric Triglyceride
Sodium Stearoyl Glutamate
Stearic Acid
Betaine
Squalane
Lecithin
Caprylyl Methicone
Disodium EDTA
Polysorbate 20
Tocopherol
Caprylyl Glycol
Glyceryl Caprylate
Pentylene Glycol
Oleic Acid
Palmitic Acid
Hexylene Glycol
Propanediol
Polyisobutene
Potassium Sorbate
Levulinic Acid
Sodium Hydroxide
Helianthus Annuus Seed Oil
P-Anisic Acid
Sorbitan Isostearate
Ethylhexylglycerin
Phenoxyethanol
Water, Glycerin, Niacinamide, Isopropyl Palmitate, Polyacrylate-13, Butylene Glycol, Palmitoyl Hexapeptide-12, Palmitoyl Tripeptide-1, Palmitoyl Tripeptide-5, Palmitoyl Dipeptide-5 Diaminobutyroyl Hydroxythreonine, Palmitoyl Dipeptide-5 Diaminohydroxybutyrate, Acetyl Hexapeptide-38, Octapeptide-45, Swertia Chirata Extract, Magnolol, Ornithine, Ceramide AP, Ceramide NP, Ergothioneine, Dunaliella Salina Extract, Phytosterols, Phospholipids, Glycolipids, Tremella Fuciformis Sporocarp Extract, Caprylic/Capric Triglyceride, Sodium Stearoyl Glutamate, Stearic Acid, Betaine, Squalane, Lecithin, Caprylyl Methicone, Disodium EDTA, Polysorbate 20, Tocopherol, Caprylyl Glycol, Glyceryl Caprylate, Pentylene Glycol, Oleic Acid, Palmitic Acid, Hexylene Glycol, Propanediol, Polyisobutene, Potassium Sorbate, Levulinic Acid, Sodium Hydroxide, Helianthus Annuus Seed Oil, P-Anisic Acid, Sorbitan Isostearate, Ethylhexylglycerin, Phenoxyethanol
Inulin
Sodium Hyaluronate
Panthenol
Alpha-Glucan Oligosaccharide
Carnosine
Carbomer
Hydroxypropyl Cyclodextrin
Citric Acid
Sodium Benzoate
Acetyl Hexapeptide-8
Tetrapeptide-21
Pentapeptide-18
Pantolactone
Palmitoyl Tripeptide-38
Palmitoyl Tetrapeptide-7
Lactic Acid/Glycolic Acid Copolymer
Polyvinyl Alcohol
Phenylpropanol
Copper Palmitoyl Heptapeptide-14
Heptapeptide-15 Palmitate
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
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Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
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.
Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
We don't have a description for Dunaliella Salina Extract yet.
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.
Glyceryl Caprylate comes from glycerin and caprylic acid. It is an emollient, co-emulsifier, and preservative booster.
Its short C8 fatty acid chain makes it behave differently from its longer-chain emollient cousins like Glyceryl Stearate. It feels more lightweight, fast-absorbing, and silky instead of rich and waxy.
As a co-emulsifier, its "head" and "tail" sit at the oil-water interface. But overall, the short C8 tail and not being water soluble means it doesn't really have the muscle to emulsify a formula on its own. That's why you'll often see it paired with a primary emulsifier like Cetearyl Glucoside.
Interestingly, Glyceryl Caprylate acts as a preservative booster. This is because its fatty-acid backbone disrupts microbial lipid membranes. It shows excellent activity against bacteria and yeast but is weaker against mold.
Typical concentrations range from 0.5-1% and this ingredient is generally non-irritating.
Because this ingredient has a C8 fatty acid chain, it is outside the range that the Malassezia yeast metabolizes (making it fungal acne safe).
Palmitoyl Tripeptide-1 (aka Pal-GHK) is a synthetic signal peptide made of three amino acids attached to palmitic acid.
That fatty acid attachment is the key: it boosts the peptide's ability to penetrate the skin barrier. This puts it closer to the dermal cells where it can actually make a difference.
Once there, it acts as a matrikine, a signaling peptide that prompts fibroblasts to produce more collagen, fibronectin, and hyaluronic acid.
In vitro studies show it can boost collagen production in skin cells even when UV-damaged skin samples were treated with it at a tiny concentration (it almost fully restored dermal collagen at 5ppm). It achieved this at 100x lower concentration than retinoic acid, which needed 500 ppm to do the same thing.
Human clinical data is promising, but modest:
A study of 23 female volunteers found a small but statistically significant increase (~4%) in skin thickness after treatment at 4 ppm.
A separate small trial of 15 women showed statistically significant reductions in wrinkle length, depth, and skin roughness after applying it twice daily for four weeks.
You'll likely see Pal-GHK paired with Palmitoyl Tetrapeptide-7 as part of the Matrixyl 3000 complex.
Fungal acne note: Usually a palmitic acid component can feed Malassezia in unbound form, but here is is covalently bonded to the peptide. This means it is very difficult for Malassezia to access, and therefore very unlikely to cause fungal acne.
Palmitoyl Tripeptide-5 is a synthetic signal lipopeptide. This just means it is a three amino acid chain bolted onto a palmitic acid tail so it can slip through the skin's lipid barrier.
This peptide has a "build more, lose less" approach.
It's designed to mimic the collagen-stimulating activity in your skin by copying a snippet of one of your skin's own matrix proteins. This nudges fibroblasts into making more collagen while inhibiting the enzyme that breaks down skin protein.
The manufacturer's in vivo study of 45 volunteers found 1% and 2.5% reduced the appearance of wrinkles by 7% and 12% respectively, after using it twice daily for 84 days.
This is in the expected range for peptides; they're slow and cumulative actives and not overnight fixers.
Typical use levels range from 1-3% and this ingredient gets along with pretty much everything.
On the fungal acne front: Although palmitic acid sits in the chain length that Malassezia can feed on, this ingredient has it locked in an amine bond. This makes it hard for Malassezia to access as a source of food, and therefore fungal acne safe.
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.
Polysorbate 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.
It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.
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.
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.
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!