We all know that there are 2 ways to deliver Vitamin C to your skin. We can eat it via food or use a topical Vitamin C serum that delivers it directly to your skin. Both methods have their own benefits and by understanding how Vitamin C works in your skin via scientific data, you can make a more informed choice about how to maximise these benefits for yourself. In this blog: What is Vitamin C? Which is the best way to deliver Vitamin C to my skin? How do I use Vitamin C products? Vitamin C side effects Products and Recommendations What is Vitamin C? Vitamin C is an antioxidant and an essential nutrient involved in the repair and maintenance of your body’s connective tissues with several impressive benefits including: hydrating dry skin, reversing ageing, repairing sun damage, and speeding up wound repair. Meanwhile, It is a key cofactor for enzymes involved in making collagen (keeps your skin plump), carnitine (helps the body turn fat into energy),  catecholamine (neurotransmitters, or hormones that help deliver signals to your brain), and plays a vital role in several immune system functions. Topical application of Vitamin C has shown improvement in pigmentation and texture by reversing age and sun damage such as melasma and wrinkling. Vitamin C serums can help even out your skin tone, protect it from sun damage and pollution damage, help improve hydration in your skin. Paired with regular sunscreen use, Vitamin C can slow down ageing in the skin both by reversing existing damage as well as preventing future damage. Which is the best way to deliver Vitamin C to my skin? Studies show that eating Vitamin C rich foods and applying Vitamin C on your skin surface both have beneficial effects for the skin, both internally and on the visible surface. Ageing causes a decline in vitamin C content in both the epidermis and dermis. Excessive exposures to UV light or pollutants (eg, cigarette smoke and ozone) may also lower vitamin C content, primarily in the epidermis. So, which method of applicatio is the best? In two human studies, oral vitamin C supplementation alone did not significantly increase Minimal Erythemal Dose (MED), a measure of photo-protection from UV light in the skin. However, multiple studies have found that oral supplementation with a combination of vitamin C and vitamin E effectively increases MED and decreases erythema-induced blood flow to damaged areas of skin. Thus, interactions between the two antioxidant vitamins may be necessary to achieve UV protection by dietary means. Topical application of vitamin C, alone or in combination with other compounds, may result in greater photoprotection than oral supplementation because of the more direct route of administration. In one mouse study, topical application of ascorbic acid delayed the effects of chronic high-dose UVB exposure on the skin, including a reduction in skin wrinkling and the development of skin tumors. In pig models, topical application of vitamin C reduced the number of sunburned cells, decreased erythema response and reduced DNA damage induced by UVA exposure. Topically applied combinations of vitamin C and vitamin E are more effective in preventing photodamage than either vitamin alone. In particular, this combination of antioxidant vitamins decreased the immunosuppressive effects of UV exposure, increased MED, and decreased cell damage.  Summary Dietary Vitamin C does not offer the same photoprotection benefits. Eating both Vitamin C and Vitamin E seems to show similar results as a topical Vitamin C application. Topical formulations that contain both Vitamin C and Vitamin E are also more potent than Vitamin C alone. Consuming Vitamin C has a lot of other benefits aside from photoprotection, but if your goal is to increase protection from the sun and its UV light, then applying vitamin C to the skin is a more efficient and direct way to deliver it to your skin.  How do I use Vitamin C products? The general rule for skincare order of operations is to work thin too thick.  Apply formulas with a thinner consistency first so they have a chance to absorb into skin before applying thicker products. Step 1: Wash your face with a low pH and non-irritating cleanser. Step 2: Apply your product Step 3: Wait a couple of minutes to let your skin absorb the product. Step 4: Continue with your skincare routine and feel free to layer on more products like moisturiser or sunscreen. Here are some tips to help you get the most out of your vitamin C skincare formulas: Use regularly. If you only apply once in a while, you won’t see results. Be patient. Don’t give up just because you don’t see immediate changes. Store correctly and adhere to use by/expiration dates to ensure the potency hasn’t been compromised. With vitamin C serum, start with a lower concentration, see how your skin reacts and adjusts to this level before moving up to the higher concentrations. Do a patch test before using a new product. Apply a small amount to the inside of the wrist or behind the ear, and wait 24-48 hours to make sure you don’t have a skin reaction before applying it to larger areas. Vitamin C side effects Vitamin C is usually less irritating than acids like beta hydroxy acids (salicylic) or alpha hydroxy acids (lactic, glycolic) or Vitamin C (retinoids), but can still have some side effects. Some people can experience side effects such as redness, stinging, peeling, or even over-exfoliation after using a Vitamin C serum. Vitamin C is a very acidic active so these side effects are not surprising. To avoid these side effects, we recommend starting off with a lower concentration of Vitamin C and/or starting off a serum by only using it once/twice a week and building up after 2-3 weeks.