Vitamin C Serum Side Effects — COUI Skincare

Vitamin C Serum Side Effects

While growing up, vitamin C equated to a glistening glass of orange juice for many of us, and that was it – an end to a long list of worries put to rest. But as I reached the age when I have to worry about various skin issues such as acne scars, dullness etc., vitamin C has turned into an important skincare ingredient. Many skincare brands these days are incorporating at least one product with Vitamin C in their line, to keep up with the growing popularity and demand.

Vitamin C serums generally consist of L-Ascorbic Acid or LAA. In most serums, the Vitamin C will be in around 10-20% concentration. For beginners, it is better to start with a lower concentration to let the skin get adjusted to the formula. With prolonged use, you can upgrade to stronger versions, as Vitamin C serum side effects can be harmful to some.

Vitamin C Serum Side Effects

Even though the Vitamin C serum is a super-heroic element that can turn into your savior, there are unfortunately, some side effects to its use. When they say it is ‘Too good to be true’, they are right to an extent. Still, precaution is better than cure. Here are some possible side effects you should prepare for, that might or might not occur once you start using a Vitamin C serum:


One of the most common side effects of using a Vitamin C serum is irritation, which then leads to redness. This is typically common for those with sensitive skin. Or if you are allergic to the L-Ascorbic acid, which is the primary base of many Vitamin C serums.

woman face irritation

If you have dry and/or sensitive skin, it is better to skip the L-Ascorbic acid and instead choose the Magnesium Ascorbyl Phosphate as the base. The latter is much gentler for those with dry and/or sensitive skin.

Also, choose a Vitamin C serum with a low pH level, but not too low as it would cause irritation. A pH on the level of 5-6 with Magnesium Ascorbyl Phosphate is the right combination for the sensitive skin. The skin’s natural pH balance is around this so you will be fine with this type of Vitamin C serum.

If you are unsure about the ingredients and don’t want to take any chances for fear of getting irritation, consider getting the COUI Super C Serum. It has been formulated to specifically cater to the people with acne prone, dry and sensitive skin. It’s an all-rounder Vitamin C serum with a Magnesium Ascorbyl Phosphate base.

The best way to avoid this Vitamin C serum side effect is to stop using it. Also, if you are using it for the first time, make sure to always do a patch test first. If irritation happens, quickly wash it off with normal water.

Irritation may occur due to many reasons. If you are still determined to use the Vitamin C serum despite this side effect, consider using it in smaller dosage. Start really small, perhaps once every 2-3 days, and build up from there.

Another source of irritation can root from using other active ingredients at the same time. Don’t mix products with retinol, Salicylic, lactic and glycolic acid, Vitamin B3 etc. when you are using a Vitamin C serum. Mixing these ingredients together will result in irritation so go easy on using the acids.


Breakouts are yet another common Vitamin C serum side effect. Many people will have breakouts from using a Vitamin C serum, which can be disheartening. Many will ask, is Vitamin C serum good for acne, the answer to which is, well, it depends.

The breakouts can happen due to the base of the Vitamin C serum. Some Vitamin C serums contain ingredients such as Ferulic acid to keep the Vitamin C stable for a longer period. This can cause problems for acne prone and sensitive skin.

To avoid getting breakouts from Vitamin C serums, make sure to thoroughly read out the ingredients list. Reading reviews can be beneficial as well. And most importantly, start slow if you are using it for the first time.

To answer the question, yes, Vitamin C serum CAN be good for acne. These serums can help protect the skin from UV damage and pollution, which will naturally result in lesser breakouts.

Flaky Skin

Flaky skin is something that might happen if you use too much of the Vitamin C serum, too soon. One of the Vitamin C serum side effects is the exfoliation. Due to this, you might get flaky skin during the first few days of usage.

baby flaky skin

Flaky skin is not entirely bad for your skin as it is only dead skin in most cases. Just don’t pick them off as it can lead to pulling off live skin, causing bleeding and even scarring in the process. Just let them be.

The flaky skin problem will stop occurring once your skin gets adjusted to the Vitamin C serum. Still it is better to use a moisturizer after using the serum. This will help in keeping the flaky skin at bay.

Sun Damage

Vitamin C serum will protect you from harmful UV, but at the same time, it can cause sun damage. Yes it sounds contradictory, but it all depends on your behavior.

Sun damage will occur as one of the Vitamin C serum side effects, but only if you don’t use a sun protection in the daytime. It is absolutely a must to use a sunscreen of at least SPF 50 while using a Vitamin C serum. If you can’t follow this rule, it is better to not use the Vitamin C serum.

You see, not using sun protection while you are using Vitamin C serum should be considered a crime. If you want to improve your overall skin with the Vitamin C serum, you must use a sunscreen every single day, without a miss.

Some Good Vitamin C Serums

There are many Vitamin C serums available in the market due to its growing popularity. Because of this, it might be a little overwhelming to choose. I will talk about two Vitamin C serums that I have used and liked.

COUI Super C Serum

I know I have already mentioned it once because of its mild ingredients list, compared to many other brands of Vitamin C serums. The COUI Super C serum is formulated with gentler ingredients which help to diminish the side effects, especially for newbies and those with sensitive skin.

COUI Super C serum is more geared towards fighting signs of aging. Not only that, but people with other skin problems such as dullness, acne scars, dehydration etc. will also be benefitted. It also has a slight lifting effect, which mainly results in adding plumpness to the skin.

The uniqueness lies on the Epidermal Growth Factor (EGF) for the Super C serum. The EGF helps in synthesizing new collagens, which makes sure that you get the most anti-aging benefit along with the other ingredients.

COUI Natural Vitamin C Serum

Here is another C serum I really like and would absolutely recommend to anyone especially because of its anti-aging properties. The Natural Vitamin C serum, however, is suitable for the veterans, as the Vitamin C is in 20% concentration. This makes the COUI Natural Vitamin C Serum a very strong serum with superior anti-aging properties.

The Natural Vitamin C serum will create new collagens to restore the structure and elasticity of your skin caused by years of damage. The exfoliating effect will help in getting glowing skin once again. The anti-oxidants of the COUI Natural Vitamin C serum will protect your skin from sun damage and harsh environment.

If you are looking for something to shade the years of aging from your face, go with this serum. But of course, you need to make sure your skin is going to be able to handle the high concentration. If you have sensitive skin or are still a Vitamin C newbie, stay away.

Final Words…

Does Vitamin C serum really work? Of course it does! The benefits are endless and it is possible to get positive results with continuous use, given that you use sunscreen regularly.

You might be curious, how long does Vitamin C serum take to work? My answer will be at least a month, or even two. And you have to keep at it as using only once in a while will not give you any results.

But one needs to know how to use Vitamin C serum to get those benefits. Using it without considering one’s skin condition and other things mentioned earlier can cause more damage than good. Be very cautious to not take the side effects of Vitamin C serum lightly.

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