Skin science article
Charlotte Tilbury Charlotte's Magic Serum Crystal Elixir Versus Youth To The People Triple Peptide + Cactus Oasis Serum
Charlotte Tilbury Charlotte's Magic Serum Crystal Elixir Versus Youth To The People Triple Peptide + Cactus Oasis Serum This anti-aging serum is formulated around Niacinamide and Polyglutamic Acid to soften the look of wrinkles and brighten dull-looking skin.
Charlotte Tilbury Charlotte's Magic Serum Crystal Elixir Versus Youth To The People Triple Peptide + Cactus Oasis Serum
This anti-aging serum is formulated around Niacinamide and Polyglutamic Acid to soften the look of wrinkles and brighten dull-looking skin.
This anti-aging serum is formulated around Opuntia Ficus-Indica Stem Extract and Palmitoyl Tripeptide-1 to soften the look of wrinkles.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Niacinamide
Glycereth-26
Triheptanoin
Glycerin
Methyl Gluceth-20
Silica
Camellia Oleifera Seed Oil
Quartz Powder
Amethyst Powder
Ruby Powder
Gold
Butyrospermum Parkii Oil
Phenoxyethanol
Dimethyl Isosorbide
Polysorbate 20
Glyceryl Stearate
Butylene Glycol
Octyldodecyl Oleate
Benzyl Alcohol
Myrothamnus Flabellifolia Leaf Extract
PEG-100 Stearate
Octyldodecyl Stearoyl Stearate
Schisandra Chinensis Fruit Extract
Carbomer
Sodium Gluconate
Sodium Hyaluronate
Chondrus Crispus Extract
Sodium Hydroxide
Saussurea Involucrata Callus Extract
Tocopheryl Acetate
Aloe Barbadensis Leaf Juice
Polyglutamic Acid
Pentylene Glycol
Sorbitol
Magnesium Aspartate
Zinc Gluconate
Rosa Canina Fruit Extract
Polyhydroxystearic Acid
Octyldodecanol
Sodium Benzoate
Propanediol
Biosaccharide Gum-4
Xanthan Gum
Parfum
Plumeria Alba Flower Extract
Plumeria Rubra Flower Extract
Lithothamnion Calcareum Extract
Lactic Acid
Potassium Sorbate
Caprylyl Glycol
Copper Gluconate
Hydrated Silica
1,2-Hexanediol
Citric Acid
Solanum Tuberosum Pulp Extract
Acetyl Tetrapeptide-11
Acetyl Tetrapeptide-9
Dehydroacetic Acid
Ascorbic Acid
Glutathione
Limonene
Geraniol
Citronellol
Linalool
Citral
Water, Niacinamide, Glycereth-26, Triheptanoin, Glycerin, Methyl Gluceth-20, Silica, Camellia Oleifera Seed Oil, Quartz Powder, Amethyst Powder, Ruby Powder, Gold, Butyrospermum Parkii Oil, Phenoxyethanol, Dimethyl Isosorbide, Polysorbate 20, Glyceryl Stearate, Butylene Glycol, Octyldodecyl Oleate, Benzyl Alcohol, Myrothamnus Flabellifolia Leaf Extract, PEG-100 Stearate, Octyldodecyl Stearoyl Stearate, Schisandra Chinensis Fruit Extract, Carbomer, Sodium Gluconate, Sodium Hyaluronate, Chondrus Crispus Extract, Sodium Hydroxide, Saussurea Involucrata Callus Extract, Tocopheryl Acetate, Aloe Barbadensis Leaf Juice, Polyglutamic Acid, Pentylene Glycol, Sorbitol, Magnesium Aspartate, Zinc Gluconate, Rosa Canina Fruit Extract, Polyhydroxystearic Acid, Octyldodecanol, Sodium Benzoate, Propanediol, Biosaccharide Gum-4, Xanthan Gum, Parfum, Plumeria Alba Flower Extract, Plumeria Rubra Flower Extract, Lithothamnion Calcareum Extract, Lactic Acid, Potassium Sorbate, Caprylyl Glycol, Copper Gluconate, Hydrated Silica, 1,2-Hexanediol, Citric Acid, Solanum Tuberosum Pulp Extract, Acetyl Tetrapeptide-11, Acetyl Tetrapeptide-9, Dehydroacetic Acid, Ascorbic Acid, Glutathione, Limonene, Geraniol, Citronellol, Linalool, Citral
Opuntia Ficus-Indica Stem Extract
Palmitoyl Tripeptide-1
Palmitoyl Tetrapeptide-7
Palmitoyl Tripeptide-28
Hydrolyzed Sodium Hyaluronate
Sodium Hyaluronate Crosspolymer
Sodium Acetylated Hyaluronate
Synthetic Sapphire
Citrullus Lanatus Fruit Extract
Lens Esculenta Fruit Extract
Pyrus Malus Fruit Extract
Nephelium Lappaceum Peel Extract
Sodium PCA
Malachite Extract
Hydroxypropyl Methylcellulose
Tetrasodium Glutamate Diacetate
Sodium Lactate
Hydroxyethylcellulose
Ethylhexylglycerin
Water, Butylene Glycol, Glycerin, Pentylene Glycol, Opuntia Ficus-Indica Stem Extract, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-28, Sodium Hyaluronate, Hydrolyzed Sodium Hyaluronate, Sodium Hyaluronate Crosspolymer, Sodium Acetylated Hyaluronate, Synthetic Sapphire, Citrullus Lanatus Fruit Extract, Lens Esculenta Fruit Extract, Pyrus Malus Fruit Extract, Nephelium Lappaceum Peel Extract, Sodium PCA, Glutathione, Malachite Extract, Citric Acid, Hydroxypropyl Methylcellulose, Tetrasodium Glutamate Diacetate, Polyglutamic Acid, 1,2-Hexanediol, Caprylyl Glycol, Sodium Lactate, Carbomer, Propanediol, Polysorbate 20, Hydroxyethylcellulose, Xanthan Gum, Phenoxyethanol, Ethylhexylglycerin
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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.
1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.
It is a:
Humectant, drawing moisture into the skin
Emollient, helping to soften skin
Solvent, dispersing and stabilizing formulas
Preservative booster, enhancing the antimicrobial activity of other preservatives
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.
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.
Glutathione is a tiny protein-like molecule (a "tripeptide" build from 3 amino acids: glycine, cysteine, and glutamic acid) that your body already makes on its own.
Inside your body, it acts as one of the skin's main antioxidants that help fight against free radicals.
In skincare, it's best known as a brightening ingredient that slows down tyrosinase, the key enzyme that makes skin pigment. It also nudges the skin toward making a lighter type of pigment instead of a darker one.
This is why you'll see it in products aimed at dark spots and uneven tone.
A small number of real human trials have found a topical glutathione lotion:
The honest caveat is that the current evidence is still thin (few studies, small groups, short timelines). Glutathione also doesn't absorb into skin very easily so results tend to be modest and fade if you stop using it.
One thing worth clearing up:
The scary side effects you may have heard about come from glutathione injected intravenously, which has real safety concerns. Applying it topically is a completely different thing and has a clean track record.
Most human studies used it around 2% (as Glutathione or Glutathione Disulfide) and a 2% oxidized glutathione lotion and a 2% S-acyl glutathione cream are the concentrations with actual clinical data behind them.
There's no established "ideal" percentage yet but 1-2% is the evidence-backed range.
Allergy-wise, there is very low risk for this ingredient; it was well-tolerated across the topical trials. Only one participant had mild temporary redness that cleared up on its own and another study reported no adverse reactions at all.
One trial had ~10% of users drop out for irritation was using a combination cream that also had 10% azelaic acid so the irritation likely wasn't from the glutathione. There's no notable contact-allergy signal for topical glutathione in the literature but patch-testing before first use is still sensible for those with sensitive skin.
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.
Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:
Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.
On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.
Typical use levels in a formula run about 1-5%.
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.
Polyglutamic Acid is made up many glutamic acids chained together. It is created from bacterial fermentation.
This ingredient is an effective skin hydrator and may help speed up wound healing. As a humectant, it draws and holds water to the skin. This ingredient is often compared to hyaluronic acid or glycerin. Similarly to hyaluronic acid, it can vary in molecular weights. This means polyglutamic acid is capable of bringing hydration to lower levels of the skin.
Fun fact: Polyglutamic Acid is found in the Japanese food, natto. It is also being used in cancer treatment studies.
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.
Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
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.