Skin science article
Dr. Jart+ Peptidin™ Firming Serum With Energy Peptides Versus Paula's Choice Peptide Booster
Dr. Jart+ Peptidin™ Firming Serum With Energy Peptides Versus Paula's Choice Peptide Booster This anti-aging serum is formulated around Niacinamide and Acetyl Hexapeptide-8 to soften the look of wrinkles and refine skin texture. This anti-aging treatment is fo
Dr. Jart+ Peptidin™ Firming Serum With Energy Peptides Versus Paula's Choice Peptide Booster
This anti-aging serum is formulated around Niacinamide and Acetyl Hexapeptide-8 to soften the look of wrinkles and refine skin texture.
This anti-aging treatment is formulated around Tripeptide-1 and Palmitoyl Tripeptide-1 to soften the look of wrinkles and refine skin texture.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Methylpropanediol
Glycerin
1,2-Hexanediol
Caprylic/Capric Triglyceride
Niacinamide
Polyglycerin-3
Borago Officinalis Extract
Algae Extract
Eclipta Prostrata Leaf Extract
Cyclohexasiloxane
Centaurea Cyanus Flower Water
Melia Azadirachta Leaf Extract
Melia Azadirachta Flower Extract
Avena Sativa Kernel Extract
Cynara Scolymus Leaf Extract
Pteris Multifida Extract
Coccinia Indica Fruit Extract
Aloe Barbadensis Flower Extract
Solanum Melongena Fruit Extract
Ocimum Sanctum Leaf Extract
Nymphaea Alba Flower Extract
Corallina Officinalis Extract
Curcuma Longa Root Extract
Nymphaea Caerulea Flower Water
Ethylhexylglycerin
Adenosine
Fructooligosaccharides
Hydrogenated Lecithin
Citrus Aurantium Bergamia Fruit Oil
Beta-Glucan
Disodium EDTA
Polyquaternium-51
Sodium Hyaluronate
Butylene Glycol
Ammonium Acryloyldimethyltaurate/Vp Copolymer
Xanthan Gum
Carbomer
Tromethamine
Inositol
Propanediol
Hydrolyzed Hyaluronic Acid
Dipropylene Glycol
Sodium Palmitoyl Proline
Lavandula Angustifolia Oil
Cholesterol
Caprylyl Glycol
Cyanocobalamin
Glycine
Acetyl Glutamine
Dipalmitoyl Hydroxyproline
Sodium Cocoyl Alaninate
Serine
Glutamic Acid
Aspartic Acid
Leucine
Alanine
Lysine
Arginine
Tyrosine
Phenylalanine
Proline
Threonine
Valine
Isoleucine
Histidine
Cysteine
Methionine
Acetyl Hexapeptide-8
Copper Tripeptide-1
Hexapeptide-9
Nonapeptide-1
Palmitoyl Pentapeptide-4
Palmitoyl Tetrapeptide-7
Palmitoyl Tripeptide-1
Tripeptide-1
Water, Methylpropanediol, Glycerin, 1,2-Hexanediol, Caprylic/Capric Triglyceride, Niacinamide, Polyglycerin-3, Borago Officinalis Extract, Algae Extract, Eclipta Prostrata Leaf Extract, Cyclohexasiloxane, Centaurea Cyanus Flower Water, Melia Azadirachta Leaf Extract, Melia Azadirachta Flower Extract, Avena Sativa Kernel Extract, Cynara Scolymus Leaf Extract, Pteris Multifida Extract, Coccinia Indica Fruit Extract, Aloe Barbadensis Flower Extract, Solanum Melongena Fruit Extract, Ocimum Sanctum Leaf Extract, Nymphaea Alba Flower Extract, Corallina Officinalis Extract, Curcuma Longa Root Extract, Nymphaea Caerulea Flower Water, Ethylhexylglycerin, Adenosine, Fructooligosaccharides, Hydrogenated Lecithin, Citrus Aurantium Bergamia Fruit Oil, Beta-Glucan, Disodium EDTA, Polyquaternium-51, Sodium Hyaluronate, Butylene Glycol, Ammonium Acryloyldimethyltaurate/Vp Copolymer, Xanthan Gum, Carbomer, Tromethamine, Inositol, Propanediol, Hydrolyzed Hyaluronic Acid, Dipropylene Glycol, Sodium Palmitoyl Proline, Lavandula Angustifolia Oil, Cholesterol, Caprylyl Glycol, Cyanocobalamin, Glycine, Acetyl Glutamine, Dipalmitoyl Hydroxyproline, Sodium Cocoyl Alaninate, Serine, Glutamic Acid, Aspartic Acid, Leucine, Alanine, Lysine, Arginine, Tyrosine, Phenylalanine, Proline, Threonine, Valine, Isoleucine, Histidine, Cysteine, Methionine, Acetyl Hexapeptide-8, Copper Tripeptide-1, Hexapeptide-9, Nonapeptide-1, Palmitoyl Pentapeptide-4, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1, Tripeptide-1
PEG-8 Dimethicone
Palmitoyl Hexapeptide-12
Myristoyl Hexapeptide-16
Myristoyl Pentapeptide-17
Hexanoyl Dipeptide-3 Norleucine Acetate
Azelaoyl Bis-Dipeptide-10
Glycoproteins
Phospholipids
Dipotassium Glycyrrhizate
Yeast Extract
PCA
Phytic Acid
Panax Ginseng Root Extract
Sodium PCA
Psidium Guajava Fruit Extract
Euterpe Oleracea Fruit Extract
Ahnfeltiopsis Concinna Extract
Dextran
Hydrolyzed Silk
Lecithin
Glyceryl Polymethacrylate
C12-16 Pareth-9
Trideceth-12
Sodium Lactate
Polysorbate 20
PEG-8
C11-15 Pareth-7
Guar Hydroxypropyltrimonium Chloride
Phytosteryl/Octyldodecyl Lauroyl Glutamate
Ectoin
Citrate Buffer
Trimethylsiloxyamodimethicone
Phenoxyethanol
Sodium Hydroxide
Water, Glycerin, PEG-8 Dimethicone, Tripeptide-1, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, Palmitoyl Hexapeptide-12, Myristoyl Hexapeptide-16, Myristoyl Pentapeptide-17, Hexanoyl Dipeptide-3 Norleucine Acetate, Azelaoyl Bis-Dipeptide-10, Glycoproteins, Phospholipids, Adenosine, Dipotassium Glycyrrhizate, Arginine, Valine, Glycine, Alanine, Glutamic Acid, Serine, Threonine, Yeast Extract, Isoleucine, Proline, Histidine, Phenylalanine, PCA, Phytic Acid, Panax Ginseng Root Extract, Sodium PCA, Psidium Guajava Fruit Extract, Euterpe Oleracea Fruit Extract, Ahnfeltiopsis Concinna Extract, Dextran, Hydrolyzed Silk, Lecithin, Glyceryl Polymethacrylate, C12-16 Pareth-9, Trideceth-12, Sodium Lactate, Carbomer, Aspartic Acid, Polysorbate 20, Butylene Glycol, Caprylyl Glycol, PEG-8, C11-15 Pareth-7, Guar Hydroxypropyltrimonium Chloride, Phytosteryl/Octyldodecyl Lauroyl Glutamate, Ectoin, Citrate Buffer, Trimethylsiloxyamodimethicone, Phenoxyethanol, Sodium Hydroxide, Ethylhexylglycerin
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Adenosine is a purine nucleoside that your body already makes in every cell. In skincare, it acts mainly as a skin conditioning and anti-aging agent.
The way it works is fairly well mapped out:
Your skin has cells called fibroblasts that build collagen (the stuff that keeps skin firm and smooth). Adenosine basically flips a switch on these cells that tells them to get to work making more collagen and other proteins. These cells slow down on their own as skin ages, so Adenosine helps give them a little nudge to keep going.
The clinical backing is pretty solid too.
A blind, randomized, placebo-controlled trial of 126 women aged 45-65 tested a 0.1% cream twice daily and found real improvements in crow's feet and frown lines using a precise 3D skin-mapping technique; these changes showed up by week 3 and held at 2 months.
A later study using Adenosine-loaded dissolving microneedle patches reported gains in wrinkle depth, dermal density, elasticity, and hydration.
On concentrations, South Korea's Ministry of Food and Drug Safety has set 0.04% as the approved functional anti-wrinkle level. You'll typically see this ingredient used somewhere in the 0.04-0.1% range since it works at low doses.
This ingredient has been found safe for cosmetics with the data showing no irritation or sensitization.
Overall, this is a great ingredient for any anti-aging routine and has no photosensitizing effect, so it suits both AM and PM use.
Alanine is an amino acid and is already found in the human body. Our skin uses alanine to build collagen, elastin, and keratin.
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.
Aspartic Acid is an amino acid that our bodies produce naturally. It is an antioxidant.
Our body uses Aspartic Acid to help build collagen and elastin. It also plays a role in hydrating skin.
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).
Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.
Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.
It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.
Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.
A 2024 UK study patch-tested 1,302 patients and found true allergy to the parent group of carbomer to be rare with no confirmed relevant reactions.
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.
Glutamic Acid is an amino acid that is found in all living organisms. Our bodies use this to help nerve cells in the brain communicate with other cells.
In cosmetics, glutamic acid is a famous humectant. It draws water from the air to your skin, keeping your skin hydrated (like hyaluronic acid).
An in-vitro study from 2024 found glutamic acid to play a role in inhibiting inflammation and thus a potential skin-soothing ingredient.
Other studies show it to be have potential wound healing, skin barrier repair, and hair growth properties.
Glutamic acid has poor solubility in water and other solvents.
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 is the smallest amino acid and a key building block of collagen. It's part if 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.
A study from 2022 found that an amino acid complex featuring taurine, arginine, and glycine significantly reduced skin irritation, improved redness, and accelerated the skin repair process.
Histidine is a semi-essential amino acid used by our bodies to create protein. It has humectant and skin conditioning properties.
Our bodies use histidine to create filaggrin - filaggrin is a structural protein that the skin uses in maintaining skin barrier.
One study found histidine and carnosine to be a dynamic duo for your skin:
Oral histidine has also been found to help with filaggrin-deficit skin disorders such as atopic dermatitis.
Why is it considered a semi-essential amino acid? This is because adults are able to create it but children must get it from their diet.
Isoleucine is an amino acid that helps reinforce our skin barrier. This amino acid plays a role in creating protein for the body.
Fun fact: Isoleucine is found in meat, fish, dairy, legumes, and nuts.
Palmitoyl Tetrapeptide-7 (formerly Palmitoyl Tetrapeptide-3) is a synthetic peptide. Its main job is to fight what researchers call "inflammaging".
"Inflammaging" is the slow, low-grade chronic inflammation that quietly breaks down collagen as we age.
This ingredient calms down a specific inflammation signal in your skin cells (called IL-6). When left unchecked, this signal triggers enzymes that break down collagen and elastin.
Clinical testing showed statistically significant improvements in:
Studies also found the more of this ingredient used, the more your skin produces Collagen I, fibronectin, and hyaluronic acid.
You'll likely see this ingredient paired with Palmitoyl Tripeptide-1 in the well-known Matrixyl 3000 complex for enhanced anti-aging effects.
A 3% concentration applied twice daily for two months showed meaningful skin rejuvenation results in clinical panels.
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-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.
Phenylalanine is an amino acid. It is a skin soothing and hydrating ingredient. Amino acids play a crucial role in wound healing and skin hydration.
This ingredient is also used to help even out skin tone due to its ability to disrupt the melanin production process.
Two structures of phenylalanine exist: L-phenylalanine and D-phenylalanine. L-phenylalanine is essential, this means our bodies cannot produce it naturally and we must get it from foods. Our bodies convert D-phenylalanine to neurotransmitters, and D-phenylalanine is found in our bodies naturally.
Some foods that contain L-phenylalanine include eggs, soybeans, beef, milk.
Proline is a non-essential amino acid, meaning your body can make it on its own. In skincare, it is a skin conditioning ingredient that keeps skin soft and hydrated.
It makes up about 23% of the collagen molecule (collagen is the protein responsible for keeping your skin firm) and is involved in your skin's natural hyaluronic acid production. When applied topically, proline can penetrate the skin fairly well due to its small molecular size.
Reviews of this ingredient have found it to be neither a dermal irritant nor a sensitizer.
Fun fact: Proline can be found in protein-rich foods like meat, fish, eggs, and dairy.
Serine is a non-essential amino acid (your body makes it on its own!). It is a major player in 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.
Serine is one of your NMF's most abundant components that works as a skin-identical humectant. Its hydroxyl group grabs onto water molecules to boost hydration without any heaviness or occlusion.
Research on a hydrogel with serine confirmed this serine got delivered to your stratum corneum and demonstrated enhanced skin moisturization.
Interestingly serine also helps your skin produce filaggrin, a protein that keeps your skin barrier strong and used to create collagen.
Threonine is an amino-acid. It helps hydrate the skin and has antioxidant benefits.
Our skin uses threonine for creating collagen and elastin. Humans are not able to create threonine and must get it through eating foods such as fish, lentils, poultry, sesame seeds, and more.
Tripeptide-1, also known as GHK), is a small, three-amino-acid peptide made up of glycine, histidine, and lysine.
This ingredient is a signal peptide and tell your skin to start producing fresh collagen, elastin, and other key structural proteins. This helps maintain firmness and reduces the look of fine-lines/wrinkles.
GHK is also unique because is also acts as a carrier peptide. It binds to and transports copper ions (forming the complex GHK-Cu). This form has been studied for decades and is known to stimulate wound healing, boost antioxidant defenses, and promote collagen/elastin synthesis.
In-vitro studies show both GHK and GHK-CU increase fibroblast activity that enhances the production of collagen, elastin, fibronectin, and other extracellular matrix components.
Both of these compounds also help balance enzymes that control collagen breakdown.
Human studies (in-vivo) using GHK-Cu creams have reported visible improvements to skin density, elasticity, and wrinkle depth after several weeks of use.
A small clinical study also found topical collagen tripeptide improved wrinkle appearance and skin elasticity in women after four weeks.
While these results are promising, most research is based on GHK-Cu or its derivatives rather than Tripeptide-1 alone (Palmitoyl Tripeptide-1 is a famous derivative of GHK). However, the consensus still supports GHK as a potent skin-signaling molecule that can encourage regeneration and maintain youthful looking skin.
Fun fact: GHK is a naturally occurring fragment of type 1 collagen that can be found in human plasma, saliva, and urine.
Valine is one of the essential amino acids (meaning your body can't make it on its own and has to get it from food).
In skincare, it's usually synthetically-made or pulled from plant proteins like soy.
It's one of the small building blocks that make up your skin's natural moisturizing factor (NMF), or the built-in system that helps skin hold onto water. So its main job in a formula is to give the skin gentle hydration and help it feel more comfortable.
Typical amounts are very tiny: roughly 0.00004%-0.5% in leave on products and up to 1% in rinse-off ones.
The Cosmetic Ingredient Review panel has looked at this ingredient and found no evidence of it being a skin irritant or allergen at cosmetic levels.
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!