Obagi Professional-C Serum 15% Versus Obagi Professional-C Serum 20%

Obagi Professional-C Serum 15% Versus Obagi Professional-C Serum 20% Detailed comparison of Obagi Professional-C Serum 15% versus Obagi Professional-C Serum 20%. This brightening serum is formulated around Ascorbic Acid and Ascorbyl Glucoside to brighten dull-looking skin and fade the look of dark spots. This brightening serum is formulated around Ascorbic Acid and Ascorbyl Glucoside to brighten dull-looking skin and soften the look of wrinkles. Propylene Glycol Water Ascorbic Acid Alcohol Ascorbyl Glucoside Parfum Propylene Glycol, Water, Ascorbic Acid, Alcohol, Ascorbyl Glucoside, Parfum Ethoxydiglycol Phenoxyethanol Sorbitol Sodium Hyaluronate Zinc Chloride Calcium Hydroxide Propylene Glycol, Water, Ascorbic Acid, Alcohol, Ascorbyl Glucoside, Ethoxydiglycol, Phenoxyethanol, Sorbitol, Sodium Hyaluronate, Zinc Chloride, Calcium Hydroxide, Parfum These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. This ingredient is also called ethanol or ethyl alcohol. It is denatured, meaning made undrinkable for cosmetic use. In formulas, it: Is it bad for your skin? The answer comes down to concentration. Patch and wash studies have found highly concentrated alcohol-based hand rubs (60-100%) cause less barrier disruption than washing with a basic detergent like SLS. The only measurable effect in these studies was a temporary dip in skin hydration. Concentrations below 12-15% in leave-on cosmetics is generally well-tolerated. Concentrations above start to see increased transepidermal water loss (TEWL) and reduced hydration. In concentrations about 58%, it creates temporary channels in your skin's lipid layers to become more permeable and allow other ingredients to slip through easily. This ingredient can be up to 80% of the formula in alcohol-based perfumes. Overall, this ingredient is probably harmless if found lower down an ingredients list but worth side-eyeing if it's high up (especially if your barrier is already struggling). Alcohol can worsen dry skin, eczema, and oily skin, especially at higher concentrations. This is because it can increase transepidermal water loss and decrease hydration to disrupt the skin barrier. According to the National Rosacea Society based in the US, you should be mindful of products with these alcohols in the top half of ingredients. True allergic contact dermatitis to ethanol is uncommon, but be sure to patch test if you have dry or sensitive skin. Ascorbic Acid is is pure Vitamin C and is the biologically active form used directly by skin. Not only is vitamin C great for your overall health and immune system, but it also has plenty of benefits for your skin. It is best supported by academic literature for: Topical vitamin C has been shown to help neutralize oxidative stress from UV and pollution, helping to improve photoaging and hyperpigmentation when used consistently. One clinical study found that using 5% topical vitamin C for six months improved signs of photodamaged skin, both on the surface and in the deeper structural layers of the skin. While vitamin C doesn’t replace sunscreen, studies show it can boost photoprotection when combined with Vitamin E and ferulic acid. These two ingredients help improve stability and protective effects. The big downside of this ingredient is formulation difficulty. Vitamin C is prone to oxidation and doesn't penetrate the skin unless formulated correctly. Research found that vitamin C absorbs into the skin best at a low pH (< 3.5) with about 20% being the upper limit for effective absorption. Skin levels can saturate after repeated application; this means your skin won’t keep absorbing more once it’s full of vitamin C. This is why more isn’t always better with vitamin C and why very high concentrations don’t necessarily give extra benefits. Ascorbi