Paula's Choice C15 Super Booster Versus Paula's Choice 10% Azelaic Acid Booster

Paula's Choice C15 Super Booster Versus Paula's Choice 10% Azelaic Acid Booster Detailed comparison of Paula's Choice C15 Super Booster versus Paula's Choice 10% Azelaic Acid Booster. This brightening serum is formulated around Ascorbic Acid and Ferulic Acid to brighten dull-looking skin and soften the look of wrinkles. This calming treatment is formulated around Azelaic Acid and Salicylic Acid to calm redness and fade the look of dark spots. Water Ascorbic Acid Dipropylene Glycol Propanediol Glycerin Ethoxydiglycol Sodium Hydroxide PPG-26-Buteth-26 PEG-40 Hydrogenated Castor Oil Bisabolol Ferulic Acid Sodium Phytate Decylene Glycol Tocopherol 1,2-Hexanediol Sphingomonas Ferment Extract Phenoxyethanol Water, Ascorbic Acid, Dipropylene Glycol, Propanediol, Glycerin, Ethoxydiglycol, Sodium Hydroxide, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, Bisabolol, Ferulic Acid, Sodium Phytate, Decylene Glycol, Tocopherol, 1,2-Hexanediol, Sphingomonas Ferment Extract, Phenoxyethanol Azelaic Acid C12-15 Alkyl Benzoate Caprylic/Capric Triglyceride Methyl Glucose Sesquistearate Cetearyl Alcohol Glyceryl Stearate Dimethicone Salicylic Acid Adenosine Glycyrrhiza Glabra Root Extract Boerhavia Diffusa Root Extract Allantoin Cyclopentasiloxane Xanthan Gum Sclerotium Gum Butylene Glycol Water, Azelaic Acid, C12-15 Alkyl Benzoate, Caprylic/Capric Triglyceride, Methyl Glucose Sesquistearate, Glycerin, Cetearyl Alcohol, Glyceryl Stearate, Dimethicone, Salicylic Acid, Adenosine, Glycyrrhiza Glabra Root Extract, Boerhavia Diffusa Root Extract, Allantoin, Bisabolol, Cyclopentasiloxane, Xanthan Gum, Sclerotium Gum, Propanediol, Butylene Glycol, Phenoxyethanol These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. Bisabolol is a gentle skin conditioner, antioxidant, and soothing ingredient. It's primary claim to fame is soothing and research shows topically applied bisabolol can quiet the chemical messengers that cause your skin to become inflamed, helping to sooth any irritation. A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin. In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum. You'll likely see use concentrations quite low, usually 0.1-0.2%. Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure 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. 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 t