Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

K18 Hair PEPTIDE PREP™ Clarifying Detox Shampoo Versus Paul Mitchell Shampoo Two

K18 Hair PEPTIDE PREP™ Clarifying Detox Shampoo Versus Paul Mitchell Shampoo Two Detailed comparison of K18 Hair PEPTIDE PREP™ Clarifying Detox Shampoo versus Paul Mitchell Shampoo Two. No key ingredients Water Sodium C14-16 Olefin Sulfonate Cocamidopropyl Hyd

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K18 Hair PEPTIDE PREP™ Clarifying Detox Shampoo Versus Paul Mitchell Shampoo Two Detailed comparison of K18 Hair PEPTIDE PREP™ Clarifying Detox Shampoo versus Paul Mitchell Shampoo Two. No key ingredients Water Sodium C14-16 Olefin Sulfonate Cocamidopropyl Hydroxysultaine Salicylic Acid Charcoal Powder Sh-Oligopeptide-78 Panthenol Glycerin Sodium Phytate Guar Hydroxypropyltrimonium Chloride Caprylyl Glycol Caprylhydroxamic Acid Citric Acid Potassium Hydroxide Sodium Hydroxide Parfum Benzyl Salicylate Limonene Water, Sodium C14-16 Olefin Sulfonate, Cocamidopropyl Hydroxysultaine, Salicylic Acid, Charcoal Powder, Sh-Oligopeptide-78, Panthenol, Glycerin, Sodium Phytate, Guar Hydroxypropyltrimonium Chloride, Caprylyl Glycol, Caprylhydroxamic Acid, Citric Acid, Potassium Hydroxide, Sodium Hydroxide, Parfum, Benzyl Salicylate, Limonene Sodium Lauryl Sulfate Cocamidopropyl Betaine Sodium Chloride Hydroxypropyl Methylcellulose Polyquaternium-44 Ethylhexylglycerin Magnesium Nitrate Magnesium Chloride Tetrasodium EDTA Phenoxyethanol Methylchloroisothiazolinone Methylisothiazolinone Benzyl Benzoate Citral Citrus Aurantium Peel Oil Pinene Water, Sodium Lauryl Sulfate, Cocamidopropyl Betaine, Sodium Chloride, Panthenol, Hydroxypropyl Methylcellulose, Glycerin, Polyquaternium-44, Ethylhexylglycerin, Magnesium Nitrate, Magnesium Chloride, Tetrasodium EDTA, Citric Acid, Phenoxyethanol, Methylchloroisothiazolinone, Methylisothiazolinone, Parfum, Benzyl Benzoate, Citral, Citrus Aurantium Peel Oil, Limonene, Pinene These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. 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. 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. Limonene is a fragrance that adds scent and taste to a formulation. It's found in the peel oil of citrus fruits and other plants such as lavender and eucalyptus. The scent of limonene is generally described as "sweet citrus". Limonene acts as an antioxidant, meaning it helps neutralize free radicals. When exposed to air, oxidized limonene may sensitize the skin. Because of this, limonene is often avoided by people with sensitive skin. The term 'fragrance' is not re