Vitamin C is one of the most exciting, research-proven ingredients you can apply to skin. This water-soluble antioxidant is a natural component of healthy skin. When we’re young, vitamin C levels in skin’s outermost two layers (epidermis and dermis) are abundant, but as we age, these levels naturally deplete. Unprotected sun exposure (UV damage) and pollution can accelerate this decline, leading to skin looking and feeling dull, uneven, and less firm than it once was. Luckily, there are topical skin care solutions that can help mitigate this damage, so skin looks and feels healthier and younger longer.
Vitamin C’s benefits for skin are vast, including its ability to even out skin tone and diminish the appearance of fine lines and wrinkles. While this powerhouse ingredient is well-known for its skin-brightening benefits, research also shows it can shield skin from the visible impacts of environmental stressors, including free radical damage. This synergy of mitigating problems both before and after they occur makes vitamin C a force to be reckoned with.
There are many forms of vitamin C for skin, and while they all have antioxidant benefits, some types of vitamin C work better in skin care formulas than others. Ascorbic acid—also known as L-ascorbic acid—has the most skin-related research of any form of vitamin C. When properly formulated at a pH of less than 4 (2.6-3.2 is the ideal range), this form helps create younger-looking, firmer-feeling skin while fading signs of uneven skin tone and spots. Ascorbic acid also helps skin’s surface defend itself from free radicals and external stressors, lessening the effects of exposure to the elements.
Other beneficial forms that have notable research demonstrating their efficacy include sodium ascorbyl phosphate, ascorbyl palmitate, 3-O ethyl ascorbic acid, tetrahexyldecyl ascorbate, magnesium ascorbyl phosphate, and ascorbyl glucoside. Just keep in mind that vitamin C is extremely sensitive to air and light and will break down over time if routinely exposed to them. If you want to get the best possible results from your vitamin C serum or moisturiser it needs to be in an opaque, air-restrictive bottle or pump container to help ensure the ingredients remain stable. A vitamin C cream that comes in a jar, unfortunately, won’t remain effective for long.
Research shows that high strengths of vitamin C (10% and higher - typically found in targeted treatments or serums) are particularly effective and provide a host of benefits for skin. If your skin looks dull or its tone is uneven, regardless of your skin type, a lightweight liquid 15% vitamin C booster is ideal for layering. If stubborn dark spots are more of your concern, a richer-textured 25% vitamin C treatment works great for delivery into skin wherever discolorations and dullness are noticeable.
Lower concentrations of vitamin C are good for your skin as well, providing cumulative benefits in leave-on products such as moisturisers, eye creams, and serums. In fact, research has shown that concentrations as low as 0.6% provide antioxidant and anti-aging benefits to skin. Lower strengths of vitamin C also help enhance the benefits of other youth-preserving ingredients such as retinol and ceramides.
All forms of vitamin C mix well and layer with other skin care ingredients, including exfoliating acids and other vitamins and antioxidants, such as retinol and niacinamide. Vitamin C can be used twice daily, both morning and night. After cleansing, toning and exfoliating, apply the rest of your products in order from thinnest to thickest texture (commonly: serum, moisturiser, treatments). During the day, always finish with a moisturiser with broad-spectrum SPF 30 or greater.