7 Best Korean Vitamin C Serums with L-Ascorbic Acid in 2023

Unlike Western skincare culture, skin brightening is probably the highest-ranking concern in Korean and Japanese skincare. No matter what type of hyperpigmentation your skin has, such as acne scarring, sun damage, or melasma, a vitamin C serum is a must-have in your skincare routine if you’d like to brighten your skin.

But how does a vitamin C serum work, and what should you look for in a vitamin C serum? Where does a vitamin C serum fit into your skincare routine? And can you use it with other skincare products such as BHA, AHA, or niacinamide?

What Is Vitamin C?

We all know how vital vitamin C is nutritionally in our everyday diet, but did you know that it’s also a powerful ingredient with many benefits when it comes to skincare?

Vitamin C is simply a water-soluble nutrient that acts as an antioxidant in the body by protecting cells from the damage caused by free radicals, known as oxidative damage. This, of course, includes skin cells. Vitamin C can help fight free radicals and prevent damage caused by ultraviolet light, aka sun damage.

Not only is vitamin C good at fading hyperpigmentation and general skin brightening, but boosting the skin’s collagen production and decreasing trans-epidermal water loss can also help reduce fine lines and wrinkles. Making it the perfect anti-aging ingredient!

Who doesn’t want brighter, firmer, and plumper skin?

Vitamin C for Hyperpigmentation

Without going too much into biochemistry, what makes vitamin C such a sought-after ingredient when it comes to fading hyperpigmentation?

Vitamin C reduces the activity of tyrosinase, an enzyme involved in the formation of melanin in skin cells, by interacting with copper ions at the tyrosinase active site. Or, in other words, it inhibits the production of melanin, thereby preventing hyperpigmentation.

I want to point out something essential. Prevention. Vitamin C only prevents hyperpigmentation. It cannot fade existing hyperpigmentation. To prevent new hyperpigmentation from forming i is therefore important to wear a broadspectrum high SPF daily.

Use ingredients such as alpha-hydroxy acids (AHAs) or beta-hydroxy acids (BHAs) to increase the cell turnover rate of your skin to reveal newer and brighter skin. Without these additional steps, you would likely not see any effects when using a vitamin C serum and would be wasting your valuable money.

Related articles:

How To Fade Hyperpigmentation And Get Brighter Skin With Korean Skincare

Vitamin C Serum for Fading Post-inflammatory Hyperpigmentation

One of the most common skin concerns is acne marks, also known as post-inflammatory hyperpigmentation (PIH). Acne marks look darker than the rest of your skin—as opposed to acne scars, which are depressions left in the skin.

When a pimple heals, it can leave a mark or a scar on the skin. This happens because the skin’s normal healing process is interrupted by inflammation or infection. A mark is usually a dark or red spot that fades over time. A scar is usually permanent and requires dermatologist treatments (such as laser or dermal fillers) to minimize its appearance. Acne marks, however, can fade naturally over time (over about 3 to 6 months as your skin cells turnover).

Vitamin C can be used to speed up this process of fading PIH. This is due to its ability to stimulate collagen production, speeding up healing. Vitamin C also helps to fade PIH by inhibiting the production of melanin (which can darken spots, especially in the sun). Just don’t forget your sunscreen during the day!

What To Look For in a Vitamin C Serum

There are a few things to consider when choosing a vitamin C serum. This includes what form of vitamin C the product contains, what percentage of vitamin C the product contains (the concentration), what type of packaging the serum comes in, and what other beneficial skincare ingredients the product may be formulated with.

Sodium Ascorbyl Phosphate vs. L-Ascorbic Acid: A Guide

What Form of Vitamin C Is the Most Effective at Fading Hyperpigmentation?

There are many forms of vitamin C, including:

• ascorbic acid (also known as L-ascorbic acid or L-AA);
• sodium ascorbyl phosphate;
• ascorbyl palmitate;
• retinyl ascorbate;
• tetrahexyldecyl ascorbate;
• magnesium ascorbyl phosphate;
• ascorbyl glucoside;
• 3-O ethyl ascorbic acid (a relatively new form).

However, some forms work better than others, so paying attention to this when buying a vitamin C serum is essential.

Choosing a product containing L-ascorbic acid is best for maximum anti-aging and skin-brightening properties, as it is the form of vitamin C with the most skin-related research behind it. It has also consistently been shown to be the most effective form of penetrating the skin barrier.

Sadly, L-ascorbic acid is a highly unstable ingredient. It oxidizes (breaks down) quickly when exposed to light and air and becomes ineffective. It’s, therefore, essential to verify that the L-ascorbic acid in your serum is stabilized (more on that below).

The other two forms of vitamin C that also work well for anti-aging are Tetrahexyldecyl ascorbate and magnesium ascorbyl phosphate.

Related article:

Vitamin C serum L-Ascorbic Acid (LAA)

The Importance of Vitamin C Concentration in Serums

The efficacy of a vitamin C serum is proportional to the concentration, meaning that the higher the concentration of vitamin C in a product, the more effective it is at brightening the skin.

Studies have shown that even a vitamin C concentration as low as 0.6% provides antioxidant and anti-aging benefits to the skin. However, a concentration of 20% has been shown to have the most significant effect on fading hyperpigmentation. Studies have also shown that concentrations above 20% don’t result in higher efficacy.

Serums containing a large amount of vitamin C usually do state the concentration. If the serum you are using or would like to purchase doesn’t say the concentration, it’s likely that it contains a small amount of vitamin C.

Preventing Vitamin C Oxidation: The Importance of Product Packaging and Storage

All antioxidants degrade very fast when they come in contact with the air (oxygen) or sunlight; vitamin C is no exception!

I highly recommend buying vitamin C serums in dark glass, opaque bottles, as this is the most stable way to store them. This is how you ensure you will get the best results from your skincare product. Since the glass bottles tend to come with a dropper and not a pump, contact with oxygen is inevitable, so I advise opening only one serum at a time. I also give my vitamin C serum a 3-month shelf life once opened, although I have heard people getting away with up to 6 months.

I store my vitamin C serum in the fridge to keep the shelf life as long as possible, as heat can also cause your product to degrade.

If you find that your vitamin C serum has changed to a tan or brown color, then it means it has oxidized. Never apply an oxidized product, as it will generate free radicals in your skin, causing damage instead of preventing it.

Other Beneficial Ingredients That Work Well With Vitamin C

What ingredients should your vitamin C serum contain? I’ve already talked about L-AA being the preferred form of vitamin C. Still, there are a few other beneficial ingredients that work well with vitamin C.

Yes, niacinamide is one of them.

The effectiveness of vitamin C is significantly increased when combined with other potent antioxidants such as vitamin E and ferulic acid. This is because they support each other’s antioxidant function when used together.

For example, vitamin E enhances the antioxidant effects of vitamin C when they are applied to the skin at the same time. Both vitamin C and vitamin E also play a role in protecting your skin cells from sun damage because they neutralize the free radicals generated during UV exposure. So, therefore, having both vitamins available in your serum helps prevent sun damage better than either vitamin on their own.

Vitamin C and E also work together to maintain healthy collagen, a protein important for skin strength. Vitamin C is needed to help synthesize collagen, and vitamin E is required to maintain proper cross-links between collagen fibers.

Ferulic acid is also a potent antioxidant, naturally occurring in the cell walls of plants. Skincare-related studies have shown it can enhance vitamin C and E’s effects. It is believed that ferulic acid increases the stability of vitamin C in water solution and almost doubles the effectiveness of vitamin C and vitamin E’s ability to protect the skin against UV damage.

So, when searching for a vitamin C serum, I highly recommend choosing one that also contains either vitamin E or ferulic acid, or even better, both!

When to Use Vitamin C in Your Skincare Routine?

You can apply your vitamin C serum in the morning or the evening. Due to its photo-protective effects, many prefer it during their morning routine. Remember, it only boosts your sunscreen’s protection. It doesn’t replace it!

In terms of when to apply your vitamin C serum in your routine, you should:

1. First cleanse
2. Second cleanse
3. Cleansing toner
4. ph balancing toner
5. Vitamin C serum, wait 15 minutes.
6. BHA
7. AHA
8. Hydrating toners
9. Serum
10. Moisturizer
11. Sunscreen

In the AM, you don’t need three types of cleansers. Except for sunscreen, all products listed are optional. Unless your skin tolerates actives very well, I would recommend perhaps applying the vitamin C serum in the morning and your BHA and AHA in the evening, or even better, using them on alternate days.

Like most actives, vitamin C requires a 15-20 minute absorption window because it is pH-dependent (L-ascorbic acid). You must wait 15-20 minutes after applying your vitamin C serum before applying the following product in your routine.

Best Korean Vitamin C Serums

Let’s look at the current Korean vitamin C serums and which ones I think would be the most effective. Reasons for choosing these:

• It contains at least 20% pure vitamin C L-Ascorbic Acid;
• It contains vitamin E;
• It contains ferulic acid;
• It comes in a dark glass dropper bottle or pump bottle.

It’s important to note that these serums have high concentrations of L-Ascorbic Acid and may not be suitable for someone who is new to Vitamin C.

1. Innisfree Vitamin C 23 Ampoule

My top pick for a Korean vitamin C serum is the Innisfree Vitamin C 23 Ampoule, which checks all boxes. It is highly concentrated, containing 23% pure vitamin C (L-ascorbic acid), vitamin E, and Ferulic Acid, and comes in an opaque bottle.

It includes adenosine (antiaging), glycerin, butylene glycol (humectants for skin hydration), and two soothing herbal extracts. Panthenol is another excellent humectant that reaches into the deepest layers of the skin and has anti-inflammatory properties.

Constant use of this serum has given me glow-from-within skin. It’s my hero product for fading post-acne marks and dull skin.

The shelf life of this serum is about three months as it contains pure vitamin C. The shelf life can be extended if the serum is kept refrigerated.

Pros:

• Contains the golden trifecta: 23% LAA, Ferulic Acid and Vitamin E;
• Contains Hydrating & soothing ingredients;
• Minimal ingredients list;
• Opaque bottle prevents oxidation;
• Fragrance and essential oil free.

Cons:

• It contains alcohol and fragrance.

2. Tiam Vitamin C24 Surprise Serum

Tia’m Vitamin C24 Surprise Serum has a thick, clear, colorless liquid consistency, but spreads effortlessly. It is also excellent at hydrating the skin. I appreciate that it doesn’t have essential oils or fragrance added.
I notice some redness has faded, lightening of my acne scars and the general evenness of my face. With the outcomes I’ve seen so far, I have high expectations for this.

Tia’m Vitamin C24 Surprise Serum contains a whopping concentration of pure Vitamin C – 22% and 2% Vitamin C derivative. This powerful little bottle of vitamin C is a good dupe of the notoriously priced Skinceuticals Vitamin C + Vitamin E + Ferulic Acid Serum, which contains only 15% L-ascorbic acid.

Tia’m Vitamin C24 Surprise Serum is designed to maximize the benefits of Vitamin C while minimizing the risk of irritation. It contains vitamin E and Ferulic Acid.

It does not contain water. This helps prevent oxidation, which can cause Vitamin C to lose its potency and turn amber over time. Instead, high in the ingredients list is glycerin, which is one of the most effective humectants used in skincare products, and it’s naturally present in our skin as part of the natural moisturizing factor.

The serum’s thick consistency may make it difficult to spread evenly onto the skin, but this may also make it easier to target specific areas of concern, such as blemishes, dark spots, and dull skin. Overall, this brightening serum suits those looking to improve their skin’s appearance by targeting specific concerns with a high concentration of Vitamin C. This gentle, fast-absorbing serum leaves my skin hydrated and nourished with a glowing effect.

Pros:

• Contains the golden trifecta: 23% LAA, Ferulic Acid and Vitamin E;
• It includes another Vitamin C derivative plus hydrating and soothing ingredients;
• Short ingredients list;
• The dark dropper bottle helps prevent oxidation;
• Fragrance and essential oil free;
• Cruelty-free;

Cons:

• It leaves my skin feeling tacky.

3. Anua Green Lemon Vitamin C Blemish Serum

Anua Green Lemon Vitamin C Blemish Serum contains 20% pure vitamin C, E, and Ferulic Acid. I also like that this serum contains four types of hyaluronic acid and many other humectants. The power-duo adenosine & niacinamide help reduce fine lines and hyperpigmentation.

Anua Green Lemon Vitamin C Blemish Serum is a lightweight oil-like consistency but absorbs well into the skin. The finish is very smooth and not sticky at all. I noticed that my skin looked more radiant the next morning. This serum needs to be stored in the fridge after opening.

Pros:

• Contains optimal percentage of 20% pure LAA Vitaminc C, plus Vitamin E and Ferulic Acid;
• It contains SAP, another Vitamin C derivative, plus hydrating and soothing ingredients;
• Four types of hyaluronic acid
• Opaque dropper bottle helps prevent oxidation.

Cons:

• The downside of this serum is that it contains some essential oils;
• Has a strong lemon-lime scent.

4. ELMT Pure Vitamin C 20% Element

Pure Vitamin C 20% Element uses vitamin C in its purest form of ascorbic acid. It’s very helpful in increasing elasticity and balance as uneven skin tone.

This is the only Korean vitamin C I found with a pump bottle. This type of packaging is optimal because it helps the product avoid oxidation and prolong its lifespan.
It has a lightweight, creamy texture and doesn’t feel sticky or heavy on my skin, which I like. It hydrates by adding propanediol, butylene glycol, glycerin, and panthenol.
Although it has a creamy texture, it gives good glowing and dewy skin.

Pros:

• Contains optimal percentage of 20% pure LAA Vitaminc C and Ferulic Acid;
• It contains glycerin high in the ingredients list, which is an excellent humectant;
• Opaque pump bottle ideal for preventing oxidation.

Cons:

• It doesn’t contain vitamin E;
• It is not widely available.

5. CosRx The Vitamin C 23 Serum

Another great pick for a Korean vitamin C serum is CosRx The Vitamin C 23 Serum, which contains 23% pure vitamin C (L-ascorbic acid) and two types of vitamin E: Tocotrienols and Tocopherol. Tocotrienol is a super vitamin E. It has 50 times higher antioxidant activities than tocopherol and stimulates collagen production.

Other beneficial ingredients include licorice root extract (skin brightening and soothing), butylene glycol, allantoin, and sodium hyaluronate (humectants for skin hydration), and two types of Beta Carotene with anti-inflammatory, antioxidant, and skin-regenerative abilities. Another notable addition to the serum is niacinamide, aka vitamin B3, for skin brightening and decreasing the appearance of large pores, fine lines, and wrinkles.

Arginine is an amino acid that helps to strengthen and repair the skin’s barrier.

The shelf life of this serum is about three months as it contains pure vitamin C. The shelf life can be extended if the serum is kept refrigerated.

Pros:

• Contains 23% pure LAA Vitaminc C and two types of Vitamin E;
• It contains effective humectants and soothing ingredients;
• Opaque dropper bottle to help prevent it from oxidizing.
• It is fragrance, essential oil-free

Cons:

• It doesn’t contain ferulic acid;

6. Isntree Hyper Vitamin C 23 Serum

As the name says, Isntree Hyper Vitamin C 23 Serum contains 23% L-Ascorbic Acid, a high percent of pure Vitamin C. The Isntree serum also contains vitamin E (Tocopherol in the ingredients list), which enhances the antioxidant effects of vitamin C. As mentioned, vitamins C and E protect the skin cells from sun damage by neutralizing the free radicals generated during UV exposure. Therefore Isntree Hyper Vitamin C 23 Serum helps prevent sun damage.

Propanediol, Betaine, Polyglycerin-3, Hydroxyethyl Urea, Betula Platyphylla Japonica Juice, Panthenol, and Dextrin hydrate the skin. A special mention goes to Hydroxyethyl Urea, one of the most effective humectants in skincare but not often found in Korean cosmetics.

Pros:

• 23% LAA;
• Contains effective humectants;
• Minimal ingredients list;
• Dark bottle;
• Fragrance and essential oil free.

Cons:

• It doesn’t contain ferulic acid.

7. Mizon Real Vitamin C Ampoule

Mizon Real Vitamin C Ampoule doubles up its brightening powers with Arbutin. This serum comes in a dark brown glass dropper bottle. The bottle comes sealed with a screw-top lid, and the dropper is packaged separately to prevent any oxidation from occurring before the product reaches you.

Pros:

• It contains 19% pure LAA Vitaminc C, which is almost ideal;
• only ten ingredients;
• Opaque dropper bottle helps prevent oxidation.

Cons:

• It contains essential oils which can be sensitizing for some people;
• It does not contain vitamin E or ferulic acid.

Can I Use Vitamin C and Niacinamide Together?

So, I’ve already told you about the benefits of vitamin C. Well, niacinamide is another ingredient with loads of skin benefits. It is a skin-restoring ingredient that can visibly improve the appearance of enlarged pores, fine lines, and dull skin.

Therefore, it’s a common question: Can you use vitamin C and niacinamide in your skincare routine? There are two myths floating around on the internet that these two ingredients should not be mixed:

• Using vitamin C and niacinamide together neutralizes the effectiveness of both ingredients.
• You might create nicotinic acid that leads to skin redness when used together.

Long story short: some old research from the 1960’s was misinterpreted. You can use vitamin C and niacinamide together. Research has shown that it won’t lead to skin problems, and combining the two ingredients produces many benefits.

Can I Use Vitamin C and Retinol (Vitamin A) Together?

Retinol (a form of vitamin A) is an ingredient that provides many skincare benefits, including promoting skin renewal and enhancing collagen production). It is also a powerhouse ingredient for fading sun damage. You can read more about retinol in my hyperpigmentation post.

The above benefits make it a trendy anti-aging ingredient for women over 30. But can you combine retinol with your vitamin C serum? Again, a lot of misinformation is floating around the internet, which says that the two ingredients should not be combined mainly due to their differing pH levels.

However, research has again busted this myth. We know now that acidity doesn’t deactivate retinol. Therefore, vitamin C and retinol can be used together. Researchers found that a combination of antioxidants provides optimal results as they work to boost each other’s effectiveness. Vitamin C was found to help retinol work better by stabilizing it, and, in turn, extending its effectiveness.

If you have very sensitive skin and are still concerned about combining these two ingredients, you could include a waiting time in your routine. In this case, you would apply your vitamin C serum first, wait 30 minutes until your skin returns to its normal acidity (pH of approximately 5.5), and then follow up with a retinoid.

Another way to play it extra safe would be to use a serum containing a vitamin C derivative instead of ascorbic acid.

Due to its photo-protective effects, I prefer using vitamin C serum in the AM. Also, retinol is unstable in light, so I like using it in the PM.

Bottom Line

Vitamin C is a powerful ingredient to include in your skincare routine if you want to fade sun damage or post-inflammatory hyperpigmentation following acne breakouts.

There are a lot of vitamin C serums on the market, but my tips are to look for a serum packaged in a dark glass bottle to prevent the product from oxidizing too soon. The higher the concentration of vitamin C in the serum, the better, too (20% is the optimal amount).

Also, look for serums that include other beneficial ingredients, such as vitamin E and ferulic acid, which optimize the effectiveness of vitamin C. Research has also shown that using niacinamide and retinol with vitamin C is okay, although myths say otherwise.

Lastly, don’t waste those valuable drops of your vitamin C serum by forgetting to apply sunscreen daily.