LEITIN Skincare LS5 Copper Peptide Serum Versus Peter Thomas Roth Peptide Skinjection Amplified Wrinkle-Fix Serum
This anti-aging serum is formulated around Copper Tripeptide-1 and Palmitoyl Tripeptide-38 to soften the look of wrinkles and refine skin texture.
This anti-aging serum is formulated around Acetyl Hexapeptide-8 and Pentapeptide-18 to soften the look of wrinkles.
What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningGlycerin
HumectantHydroxyethyl Urea
HumectantPropanediol
SolventDimethyl Isosorbide
SolventEthoxydiglycol
HumectantIsostearyl Isostearate
EmollientPropylene Glycol Caprylate
Skin ConditioningCyclohexasiloxane
EmollientCyclopentasiloxane
EmollientCopper Tripeptide-1
Skin ConditioningAcetyl Tetrapeptide-9
Skin ConditioningPalmitoyl Tripeptide-38
Skin ConditioningPalmitoyl Tetrapeptide-7
Skin ConditioningPalmitoyl Tripeptide-5
Skin ConditioningTripeptide-10 Citrulline
Skin ConditioningLecithin
EmollientPEG-20 Methyl Glucose Sesquistearate
EmulsifyingMethyl Glucose Sesquistearate
EmollientGluconolactone
Skin ConditioningEthylhexylglycerin
Skin ConditioningPhenoxyethanol
PreservativeMicrocrystalline Cellulose
AbsorbentSphingomonas Ferment Extract
Skin ConditioningCaprylic/Capric Triglyceride
MaskingCellulose Gum
Emulsion StabilisingHelianthus Annuus Seed Oil
EmollientTocopherol
AntioxidantWater, Glycerin, Hydroxyethyl Urea, Propanediol, Dimethyl Isosorbide, Ethoxydiglycol, Isostearyl Isostearate, Propylene Glycol Caprylate, Cyclohexasiloxane, Cyclopentasiloxane, Copper Tripeptide-1, Acetyl Tetrapeptide-9, Palmitoyl Tripeptide-38, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-5, Tripeptide-10 Citrulline, Lecithin, PEG-20 Methyl Glucose Sesquistearate, Methyl Glucose Sesquistearate, Gluconolactone, Ethylhexylglycerin, Phenoxyethanol, Microcrystalline Cellulose, Sphingomonas Ferment Extract, Caprylic/Capric Triglyceride, Cellulose Gum, Helianthus Annuus Seed Oil, Tocopherol
Water
Skin ConditioningDimethicone
EmollientSqualane
EmollientButylene Glycol
HumectantGlycerin
HumectantSaccharomyces Lysate
Skin ConditioningPolysilicone-11
Acetyl Hexapeptide-8
HumectantPentapeptide-18
Skin ConditioningN-Prolyl Palmitoyl Tripeptide-56 Acetate
Skin ConditioningPalmitoyl Tripeptide-38
Skin ConditioningCollagen
MoisturisingSodium Hyaluronate
HumectantTocopherol
AntioxidantPhytosterols
Skin ConditioningHydrogenated Lecithin
EmulsifyingLeuconostoc/Radish Root Ferment Filtrate
AntimicrobialCitric Acid
BufferingCaprylic/Capric Triglyceride
MaskingPolyglyceryl-10 Myristate
Skin ConditioningPentylene Glycol
Skin ConditioningCaprylyl Glycol
EmollientSodium Benzoate
MaskingSodium Phytate
Sodium Hydroxide
BufferingPotassium Sorbate
PreservativeEthylhexyl Palmitate
EmollientHydroxypropyl Cyclodextrin
MaskingTrihydroxystearin
Skin ConditioningLauroyl Lysine
Skin ConditioningGlucomannan
Skin ConditioningEthylhexylglycerin
Skin ConditioningAmmonium Acryloyldimethyltaurate/Vp Copolymer
Carbomer
Emulsion StabilisingGlyceryl Stearate
EmollientStearyl Alcohol
EmollientBehenyl Alcohol
EmollientMica
Cosmetic ColorantPhenoxyethanol
PreservativeWater, Dimethicone, Squalane, Butylene Glycol, Glycerin, Saccharomyces Lysate, Polysilicone-11, Acetyl Hexapeptide-8, Pentapeptide-18, N-Prolyl Palmitoyl Tripeptide-56 Acetate, Palmitoyl Tripeptide-38, Collagen, Sodium Hyaluronate, Tocopherol, Phytosterols, Hydrogenated Lecithin, Leuconostoc/Radish Root Ferment Filtrate, Citric Acid, Caprylic/Capric Triglyceride, Polyglyceryl-10 Myristate, Pentylene Glycol, Caprylyl Glycol, Sodium Benzoate, Sodium Phytate, Sodium Hydroxide, Potassium Sorbate, Ethylhexyl Palmitate, Hydroxypropyl Cyclodextrin, Trihydroxystearin, Lauroyl Lysine, Glucomannan, Ethylhexylglycerin, Ammonium Acryloyldimethyltaurate/Vp Copolymer, Carbomer, Glyceryl Stearate, Stearyl Alcohol, Behenyl Alcohol, Mica, Phenoxyethanol
Reviews
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
In practice, that translates to a long shelf life and a consistently elegant skin feel.
While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.
Learn more about Caprylic/Capric TriglycerideEthylhexylglycerin 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.
Learn more about EthylhexylglycerinGlycerin (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.
Learn more about GlycerinThis 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.
Learn more about Palmitoyl Tripeptide-38Phenoxyethanol 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.
Learn more about PhenoxyethanolTocopherol is a fat-soluble antioxidant known as Vitamin E.
You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.
Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.
It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.
This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.
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.
In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.
Concentrations usually range from 0.1-1% in most leave-on products.
Learn more about TocopherolWater. 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!
Learn more about Water