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Skin science article

Medik8 Liquid Peptides Advanced MP Versus Peach & Lily Copper Peptide Pro Firming Serum

Medik8 Liquid Peptides Advanced MP Versus Peach & Lily Copper Peptide Pro Firming Serum This anti-aging serum is formulated around Palmitoyl Tripeptide-38 and Palmitoyl Tripeptide-5 to soften the look of wrinkles and refine skin texture. This anti-aging serum

Medik8 Liquid Peptides Advanced MP Versus Peach & Lily Copper Peptide Pro Firming Serum

This anti-aging serum is formulated around Palmitoyl Tripeptide-38 and Palmitoyl Tripeptide-5 to soften the look of wrinkles and refine skin texture.

This anti-aging serum is formulated around Copper Tripeptide-1 and Acetyl Hexapeptide-8 to soften the look of wrinkles.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Dimethicone

Dimethyl Isosorbide

Butylene Glycol

Undecane

Arginine

Inulin

Microcrystalline Cellulose

Ceteareth-20

Tridecane

Tocopherol

Hydroxyacetophenone

Sodium Hyaluronate

Palmitoyl Tripeptide-38

Panthenol

Caprylic/Capric Triglyceride

Palmitoyl Tripeptide-5

Polyacrylate Crosspolymer-6

Palmitoyl Tripeptide-1

Pullulan

Tetrapeptide-21

Palmitoyl Tetrapeptide-10

Palmitoyl Tetrapeptide-7

Ammonium Polyacryloyldimethyl Taurate

Glyceryl Linoleate

Acetyl Hexapeptide-8

Pentapeptide-18

Oligopeptide-1

Arginine/Lysine Polypeptide

Sucrose Palmitate

Cetyl Palmitate

Phenoxyethanol

Ethylhexylglycerin

Carbomer

Copper Palmitoyl Heptapeptide-14

Heptapeptide-15 Palmitate

Benzotriazolyl Dodecyl P-Cresol

Polysorbate 80

Sorbitan Stearate

Polysorbate 20

Carnosine

Sodium Metabisulfite

Dunaliella Salina Extract

Helianthus Annuus Seed Oil

Hydroxypropyl Cyclodextrin

Dimethicone/Vinyl Dimethicone Crosspolymer

Sodium Benzoate

Hydrogenated Lecithin

Caprylyl Glycol

Pantolactone

Xanthan Gum

Disodium EDTA

T-Butyl Alcohol

Potassium Sorbate

Citric Acid

Glyceryl Caprylate

Lactic Acid/Glycolic Acid Copolymer

Polyvinyl Alcohol

Phenylpropanol

Water, Glycerin, Dimethicone, Dimethyl Isosorbide, Butylene Glycol, Undecane, Arginine, Inulin, Microcrystalline Cellulose, Ceteareth-20, Tridecane, Tocopherol, Hydroxyacetophenone, Sodium Hyaluronate, Palmitoyl Tripeptide-38, Panthenol, Caprylic/Capric Triglyceride, Palmitoyl Tripeptide-5, Polyacrylate Crosspolymer-6, Palmitoyl Tripeptide-1, Pullulan, Tetrapeptide-21, Palmitoyl Tetrapeptide-10, Palmitoyl Tetrapeptide-7, Ammonium Polyacryloyldimethyl Taurate, Glyceryl Linoleate, Acetyl Hexapeptide-8, Pentapeptide-18, Oligopeptide-1, Arginine/Lysine Polypeptide, Sucrose Palmitate, Cetyl Palmitate, Phenoxyethanol, Ethylhexylglycerin, Carbomer, Copper Palmitoyl Heptapeptide-14, Heptapeptide-15 Palmitate, Benzotriazolyl Dodecyl P-Cresol, Polysorbate 80, Sorbitan Stearate, Polysorbate 20, Carnosine, Sodium Metabisulfite, Dunaliella Salina Extract, Helianthus Annuus Seed Oil, Hydroxypropyl Cyclodextrin, Dimethicone/Vinyl Dimethicone Crosspolymer, Sodium Benzoate, Hydrogenated Lecithin, Caprylyl Glycol, Pantolactone, Xanthan Gum, Disodium EDTA, T-Butyl Alcohol, Potassium Sorbate, Citric Acid, Glyceryl Caprylate, Lactic Acid/Glycolic Acid Copolymer, Polyvinyl Alcohol, Phenylpropanol

Dipropylene Glycol

1,2-Hexanediol

Betaine

Copper Tripeptide-1

Tetrapeptide-30

Heptasodium Hexacarboxymethyl Dipeptide-12

Acetyl Tetrapeptide-5

Palmitoyl Pentapeptide-4

Dipeptide-2

Tripeptide-1

Hexapeptide-9

Nonapeptide-1

Collagen Extract

Serine

Methionine

Cysteine

Acmella Oleracea Extract

Alpha-Glucan Oligosaccharide

Sodium PCA

Ulmus Davidiana Root Extract

Cichorium Intybus Root Extract

Helianthus Tuberosus Root Extract

Tremella Fuciformis Extract

Fomes Officinalis Extract

Lentinus Edodes Extract

Pyrus Malus Fruit Extract

Lens Esculenta Fruit Extract

Citrullus Lanatus Fruit Extract

Sodium Acetylated Hyaluronate

Hydrolyzed Hyaluronic Acid

Hyaluronic Acid

Sodium Hyaluronate Crosspolymer

Potassium Hyaluronate

Squalane

Ficus Carica Fruit Extract

Cynanchum Atratum Extract

Hydroxypropyltrimonium Hyaluronate

Ocimum Sanctum Leaf Extract

Melia Azadirachta Leaf Extract

Curcuma Longa Root Extract

Corallina Officinalis Extract

Solanum Melongena Fruit Extract

Coccinia Indica Fruit Extract

Gellan Gum

Adenosine

Aloe Barbadensis Flower Extract

Melia Azadirachta Flower Extract

Polyglyceryl-10 Eicosanedioate/Tetradecanedioate

Polyquaternium-51

Sodium Polyacryloyldimethyl Taurate

Hydroxyethylcellulose

Water, Dipropylene Glycol, Glycerin, 1,2-Hexanediol, Betaine, Copper Tripeptide-1, Acetyl Hexapeptide-8, Palmitoyl Tripeptide-1, Tetrapeptide-21, Tetrapeptide-30, Heptasodium Hexacarboxymethyl Dipeptide-12, Acetyl Tetrapeptide-5, Palmitoyl Tripeptide-38, Palmitoyl Pentapeptide-4, Dipeptide-2, Tripeptide-1, Hexapeptide-9, Nonapeptide-1, Collagen Extract, Serine, Methionine, Cysteine, Arginine, Acmella Oleracea Extract, Alpha-Glucan Oligosaccharide, Sodium PCA, Ulmus Davidiana Root Extract, Cichorium Intybus Root Extract, Helianthus Tuberosus Root Extract, Tremella Fuciformis Extract, Fomes Officinalis Extract, Lentinus Edodes Extract, Pyrus Malus Fruit Extract, Lens Esculenta Fruit Extract, Citrullus Lanatus Fruit Extract, Sodium Acetylated Hyaluronate, Hydrolyzed Hyaluronic Acid, Hyaluronic Acid, Sodium Hyaluronate, Sodium Hyaluronate Crosspolymer, Potassium Hyaluronate, Squalane, Ficus Carica Fruit Extract, Cynanchum Atratum Extract, Hydroxypropyltrimonium Hyaluronate, Ocimum Sanctum Leaf Extract, Melia Azadirachta Leaf Extract, Curcuma Longa Root Extract, Corallina Officinalis Extract, Solanum Melongena Fruit Extract, Coccinia Indica Fruit Extract, Gellan Gum, Butylene Glycol, Adenosine, Aloe Barbadensis Flower Extract, Melia Azadirachta Flower Extract, Polyglyceryl-10 Eicosanedioate/Tetradecanedioate, Polyquaternium-51, Sodium Polyacryloyldimethyl Taurate, Hydroxypropyl Cyclodextrin, Ethylhexylglycerin, Hydroxyethylcellulose, Caprylyl Glycol

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.

Acetyl Hexapeptide-8 (also known as Argireline) is a synthetic hexapeptide that is often called a "topical Botox alternative".

It works by mimicking how Botox relaxes muscles; it interferes with the signaling process that tells your facial muscles to contract. This can help soften expression lines like forehead wrinkles or crow's feet over time.

The comparison to Botox does have limits because the molecule is water-loving and relatively large.

Acetyl Hexapeptide-8 has a hard time absorbing deeply enough through the skin's outer barrier to actually reach the muscles.

So whether it truly works the way Botox does at a biological level is still up for debate, but early clinical outcomes are fairly encouraging.

A 12 week human study of a multi-ingredient regimen containing this ingredient saw:

While some studies have observed improvements in wrinkle appearance, it is important to note that more consistent results are seen in multi-ingredient formulations (vs just Acetyl Hexapeptide-8 alone).

Some research studies also used higher concentrations (up to 10%) while this ingredient is usually found in concentrations up to 0.005% in leave-on formulations.

Arginine is a semi-essential amino acid. This just means our bodies can product a bit on its own, but sometimes needs a little boost from food sources.

It is a part of your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.

Here's an interesting thing about Arginine: your skin converts it into urea through the Krebs-Henseleit urea cycle. Urea is one of the most effective humectants your skin naturally produces.

A clinical study showed applying 2.5% arginine hydrochloride to atopic dermatitis skin showed significant urea levels in the stratum corneum and improved moisture in just four weeks.

Arginine is also a precursor to nitric oxide; nitric oxide improves microcirculation and supports wound healing and collagen synthesis.

One study found that an amino acid complex containing Arginine reduced skin irritation, improved hydration, and accelerated skin repair in clinical / in-vivo studies.

Arginine itself is an amino acid and not a fatty acid, oil, or ester. On its own, it's not a direct food source for Malassezia, or the yeast that causes fungal acne.

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).

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.

This ingredient is used in skincare as a delivery system.

It works by "encapsulating" active ingredients with its unique ring shape that is water-loving on the outside and oil-loving on the inside. This improves the stability and absorption of the product into the skin.

According to a manufacturer, it also offer some moisturizing effects.

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.

This synthetic, signal peptide has unique skin conditioning properties in that is a matrikine-mimetic compound.

First of all, Palmitoyl Tripeptide-38 is a signal peptide; signal peptides tell the body to create more collagen.

What is a matrikine-mimetic compound?

This peptide has the ability to mimic matrikines in skin. Our skin created matrikines by breaking down matrix proteins into peptides.

Matrikines play a role in:

Though further research is needed, this ingredient seems pretty promising. In one study, women over the age of 40 with visible photoaging used a vitamin C serum with this ingredient for 56 days (15% ascorbid acid, 5 ppm palmitoyl tripeptide‐38). The results found improvement in skin roughness and skin tone.

This peptide is also part of the famous Matrixyl synthe’6, a blend of ingredients that also includes glycerin, water, and hydroxypropyl cyclodextrin.

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.

Tetrapeptide-21 is a signal peptide. It helps boost collagen, hyaluronic acid, and fibronectin.

Fibronectin is a protein found in our skin's extracellular matrix that plays a role in cell adhesion, tissue repair, and wound healing.

Tetrapeptide-21 works by mimicking skin-protein breakdown signals, telling the skin to produce new structural proteins like collagen.

Preliminary studies show it works better than matrixyl and produced twice the amount of collagen in lab tests.

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!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

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Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 03Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
  4. 04Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
  5. 05Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
  6. 06Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.
  7. 07Like 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.
  8. 08However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.
  9. 09Due 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.
  10. 10In skincare formulas, citric acid can:
  11. 11While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.
  12. 12Most 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.
  13. 13Rosacea 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.
  14. 14However, 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…
  15. 15This peptide is the copper salt and formed by reacting palmitic acid and heptapeptide-14.
  16. 16This uses a high-tech delivery system called The Cosmetic Drone, where the peptide is enclosed in a shell made from Lactic Acid/Glycolic Acid Copolymer and Polyvinyl Alcohol. Another peptide on the outside guides the capsule to fibroblast cells, the…
  17. 17Once it reaches the fibroblasts, Copper Palmitoyl Heptapeptide-14 boosts the production of collagen and elastin.
  18. 18This advanced system works at an incredibly low concentration of just 0.001%.
  19. 19Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  20. 20Topically, glycerin does several things at once:
Source · skinsort.com
02

Product index

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Comparison edit

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