Vitamin C can brighten the skin and help reduce the signs of ageing, but not all Vitamin C serums work for everyone. Although allergic reactions to Vitamin C in skincare are rare, they can happen.

Now, allergic reactions are different to irritation. Symptoms of irritation normally include redness or a mild burning sensation, and they tend to appear immediately. Irritation may also cause breakouts.

An allergic reaction, however, occurs after repeated exposure. The skin may be red, inflamed or scaly.

With Vitamin C serums, the most common cause of allergic reaction is an acidic formula. The most common form of Vitamin C is L-Ascorbic Acid, which needs to be formulated in an acidity level of pH 2.5-3. The skin’s natural pH level is 4.5 – 5.5. This difference in acidity can lead to an allergic reaction.

L-ascorbic acid is also highly prone to oxidisation. Most products come in lightproof containers to reduce the risk of oxidisation, but exposure to air can cause it to oxidise as well. When your serum is oxidised, it can irritate or even cause an allergic reaction in the skin.

To help prevent allergic reactions, we recommend using a serum with a more stable and less acidic form of Vitamin C, such as Superox-C or Magnesium Ascorbyl Phosphate. Both these forms tend to be more stable, less irritating and just as effective.

What should you do if you have an allergic reaction?

If you experience signs of irritation or allergic reaction to a Vitamin C product, stop using all your active skincare products to let the skin heal. You may want to use a gentle cleanser and a basic moisturiser to avoid aggravating your inflamed skin until it returns to normal.

In some cases, Phototherapy can also help reduce the inflammation and help your skin recover, but we recommend consulting a professional who can assess your skin’s condition ahead of time.

Can you avoid allergic reactions?

Allergic reactions tend to happen when your immune system mistakes something as a potential threat, so you don’t want to shock your skin by applying lots of Vitamin C all of a sudden.

When you start using any active ingredient, introduce it slowly. Apply a small amount every other day and gradually build up to daily use as your skin adapts.

As mentioned above, we recommend using a form of Vitamin C that is more stable and less irritating than L-Ascorbic Acid, such as Magnesium Acorbyl Phosphate or Superox-C.