Skin science article
Olaplex No.3 Hair Perfector Versus The Ordinary Multi-Peptide Serum for Hair Density
Olaplex No.3 Hair Perfector Versus The Ordinary Multi-Peptide Serum for Hair Density What's inside Key Ingredients Benefits Concerns Ingredients Side-by-side Water Bis-Aminopropyl Diglycol Dimaleate Propylene Glycol Cetearyl Alcohol Behentrimonium Methosulfate
Olaplex No.3 Hair Perfector Versus The Ordinary Multi-Peptide Serum for Hair Density
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Bis-Aminopropyl Diglycol Dimaleate
Propylene Glycol
Cetearyl Alcohol
Behentrimonium Methosulfate
Phenoxyethanol
Cetyl Alcohol
Glycerin
Hydroxyethyl Ethylcellulose
Stearamidopropyl Dimethylamine
Quaternium-91
Sodium Benzoate
Cetrimonium Methosulfate
Cetrimonium Chloride
Parfum
Tetrasodium EDTA
Polyquaternium-37
Benzyl Benzoate
Etidronic Acid
Ascorbic Acid
Phytantriol
Tocopheryl Acetate
Aloe Barbadensis Leaf Juice
Panthenol
Simmondsia Chinensis Seed Oil
Citric Acid
Potassium Sorbate
Water, Bis-Aminopropyl Diglycol Dimaleate, Propylene Glycol, Cetearyl Alcohol, Behentrimonium Methosulfate, Phenoxyethanol, Cetyl Alcohol, Glycerin, Hydroxyethyl Ethylcellulose, Stearamidopropyl Dimethylamine, Quaternium-91, Sodium Benzoate, Cetrimonium Methosulfate, Cetrimonium Chloride, Parfum, Tetrasodium EDTA, Polyquaternium-37, Benzyl Benzoate, Etidronic Acid, Ascorbic Acid, Phytantriol, Tocopheryl Acetate, Aloe Barbadensis Leaf Juice, Panthenol, Simmondsia Chinensis Seed Oil, Citric Acid, Potassium Sorbate
Propanediol
Butylene Glycol
Caffeine
Biotinoyl Tripeptide-1
Acetyl Tetrapeptide-3
Larix Europaea Wood Extract
Pisum Sativum Extract
Scutellaria Baicalensis Root Extract
Triticum Vulgare Germ Extract
Glycine Soja Germ Extract
Trifolium Pratense Flower Extract
Camellia Sinensis Leaf Extract
Apigenin
Oleanolic Acid
Arginine
Glycine
Calcium Gluconate
Zinc Chloride
Lactic Acid
Gluconolactone
Dextran
Maltodextrin
Hydroxyethylcellulose
Xanthan Gum
Pentylene Glycol
Dimethyl Isosorbide
Polysorbate 20
PPG-26-Buteth-26
PEG-40 Hydrogenated Castor Oil
Trisodium Ethylenediamine Disuccinate
Sodium Metabisulfite
Chlorphenesin
Water, Propanediol, Butylene Glycol, Glycerin, Caffeine, Biotinoyl Tripeptide-1, Acetyl Tetrapeptide-3, Larix Europaea Wood Extract, Pisum Sativum Extract, Scutellaria Baicalensis Root Extract, Triticum Vulgare Germ Extract, Glycine Soja Germ Extract, Trifolium Pratense Flower Extract, Camellia Sinensis Leaf Extract, Apigenin, Oleanolic Acid, Arginine, Glycine, Calcium Gluconate, Zinc Chloride, Lactic Acid, Gluconolactone, Dextran, Maltodextrin, Hydroxyethylcellulose, Xanthan Gum, Pentylene Glycol, Dimethyl Isosorbide, Polysorbate 20, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, Trisodium Ethylenediamine Disuccinate, Sodium Metabisulfite, Sodium Benzoate, Phenoxyethanol, Chlorphenesin
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.
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.
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.
Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.
Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.
Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.
It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.
Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.
We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.
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!