You don't need to be a total skincare buff to have heard about vitamin C for skin. You probably already know that this stuff is good for you—whether you're looking to protect the skin, ward off signs of aging, even out your skin tone, or simply get your glow on.

This potent antioxidant is one of the few ingredients that a board-certified dermatologist will always endorse. If you want to learn exactly why, then you're in the right place. Let's take a look at this much-loved ingredient, its benefits, and how to slot it into your skincare routine.

What is vitamin C?

Vitamin C is a water-soluble vitamin. It's also one of the most common vitamins found in popular fruits and vegetables, including citrus fruit and leafy greens. It's really important that we incorporate vitamin C into our diets, because the human body can't synthesize it on its own. One of vitamin C's key functions in the body pertains to our skin—to put it simply, this vitamin is the most commonly found antioxidant found there.

So, can I just eat my way to better skin? Why bother with vitamin C products?

Sadly, reaping the skincare benefits of vitamin C is not just about reshuffling your diet. When you consume vitamin C in the form of food or a supplement, the nutrients travel to many places in your body, and only a small portion reaches your skin.

If you're focused on improving the vitamin C concentration of your skin in particular, you'll want to start applying vitamin C products directly to it. But a balanced diet will, of course, complement any skincare products you use to improve your skin's health—so keep up your fruit and veg intake, too!

The different types of vitamin C

Now this is where things get a little bit more complicated. The deeper you dive into the skincare market, the more names you'll find written on the packaging of vitamin C serums and creams. The reason for this is that vitamin C is available in different forms.

But before we discuss those forms, we should also point out that this vitamin is available in two categories: active and inactive. The active form of vitamin C is highly bioavailable, meaning that it gets to work immediately after coming into contact with your skin. There is only one active form of vitamin C: L-ascorbic acid. All other forms of vitamin C are inactive, so your body needs to convert them into L-ascorbic acid (which all vitamin C is a modified version of, rather than completely separate to) before their skin benefits kick in.

You might be wondering, why bother with these inactive forms if you can just use L-ascorbic acid? It's a valid question, especially as this vitamin C form is the one with the most research behind it. One study published by the Journal of Drugs in Dermatology found it effective in reducing the "dyspigmentation, surface roughness, and fine lines" caused by skin aging, for example, while another (along with many others!) touted its ability to boost anti-aging collagen production. Simply put, it's widely known that l-ascorbic acid is a good choice if you're looking to reduce fine lines and wrinkles, fade dark spots and reverse free radical damage.

So what about the other types of vitamin C? These aren't lesser forms, by the way, and they'll still do all the good things for your skin's appearance. As we mentioned above, they have the same foundations as vitamin C's most potent type, but their molecules have been adapted. Why? It's often to make the vitamin C more tolerable for sensitive skin types, or to target specific skin concerns.

Some common forms of vitamin C for skin

Sodium Ascorbyl Phosphate (or SAP)

This is a water-soluble form of vitamin C that is notable for its high stability and potency, and its quick conversion in the skin. If you're breakout-prone, you might be interested in this vitamin C form in particular, as some research has shown that its antimicrobial properties can help to ward off any acne-causing bacteria lurking on the skin.

Magnesium Ascorbyl Phosphate (or MAP)

MAP is very similar to SAP in that it needs to convert to ascorbic acid in the skin before it can treat you to its benefits—so if you're looking for fast results, it might not be your top pick. However, it's known to be gentler than more potent options, so it's a good choice of topical vitamin C if your skin tends to get dry and irritated when you try something new on it. 

Look out for serums containing this ingredient along with other antioxidants, and they'll help to heighten its efficacy.

Ascorbyl Methylsilanol Pectinate

Just from reading the name of this ingredient, you can immediately tell there's a lot going on! Made up of many different compounds, ascorbyl methylsilanol pectinate is like vitamin C's complicated little sister. But that's not a bad thing (we all have our quirks, right?). 

One of the additional components thrown into the mix in this case is silanol, which helps this type of vitamin C penetrate the skin more effectively and deliver speedier results. It also provides added defense against free radicals, which cause visible signs of aging.

Tetrahexyldecyl Ascorbate

Here's another one that's a little bit different. Although it's inactive, tetrahexyldecyl ascorbate works harder than some other vitamin C forms because it's extra stable. As it’s oil-soluble, it won't kick-start its conversion process until it has contact with your skin's own oils, meaning that it's less likely to go to waste.

It's important to note that the list above is not exhaustive. There are many vitamin C derivates out there, but those we've mentioned are most likely to appear on a vitamin C serum in your local drugstore.

Benefits of vitamin C for the skin

Now we've covered what vitamin C is and the many forms it takes, it's now time for the good stuff: all those benefits. They include brightening your complexion (hello, glow), reducing dark spots, increasing collagen production, and protecting skin overall. Read on for three of our favorite vitamin C skincare benefits.

It's an anti-aging superhero

The more your skin's exposed to stressors like UV exposure and pollution, the more your skin accumulates free radicals. As free radicals build up, your skin's collagen and elastin production levels are affected. That, in a nutshell, is what causes aging.

As an antioxidant, vitamin C can neutralize free radicals and prevent signs of oxidative stress from showing up on your face. This does wonders for your skin's appearance, as it discourages fine lines and wrinkles from forming. Plus, by keeping collagen production amped up, your complexion will look more radiant, plump, and generally in better health.

It gives you that glow

Once you've added a good vitamin C serum to your skincare routine, you might find yourself skipping highlighter when doing your makeup. Yep, we're talking about one of the most popular benefits of vitamin C: its glow-giving abilities. 

Alongside being a powerhouse antioxidant, this vitamin is also great at increasing the nourishment and hydration of skin. It even helps to prevent transepidermal water loss (TEWL for short), so you can put dull, dry skin in the past.

It balances out your skin tone (including dark under-eye circles)

Melanin production slows down as you age, which is what causes age spots. Dark spots can occur at any age, however, due to UV damage and exposure to free radicals. Thankfully, using vitamin C helps to reduce the appearance of dark marks and discoloration. This includes under-eye circles—even though the skin around the eyes is thin and delicate, the best vitamin C serums are gentle enough to treat it with care and fade any darkness and sun damage.

Finding the best vitamin C serum

Aside from picking out the perfect variety of vitamin C for your skin (scroll up for our breakdown of the most popular types), you should also consider stability and concentration when shopping for a vitamin C serum.

On the stability front, look out for technologies like encapsulation—wherein active vitamin C is sealed in a nano- or microencapsulated casing to preserve its potency and ensure it's delivered effectively—as well as protective packaging that won't disturb the formulation within.

Concentration is also important. If you have more sensitive skin, look for a lower concentration of around 8-10%. For faster results on other skin types, look for concentrations of 10-20%.

If you're new to vitamin C serums (or just don't know where to start), we recommend the bestselling Éclat Vitamin C Serum. It's formulated with sodium ascorbic phosphate—a pure and potent form of vitamin C, suitable for sensitive skin types—at an optimal concentration of 20% to deliver fast brightening benefits. This encapsulated formula is protected by FrostProtect technology, which prolongs the serum's lifespan by shielding it from UV light, oxygen, and heat. This vitamin C serum also contains aloe vera to prevent skin irritation, along with vitamin E for added protection against fine lines and wrinkles.

How to use vitamin C in your routine

Apply vitamin C serum or cream once a day. We recommend using it as part of your morning routine, always followed by sunscreen.

Our number one tip for using topical vitamin C is to start slowly, especially if you're considering using it alongside other powerful products. This ingredient is generally suitable for all skin types but, as it's potent and active, you should take care when introducing it to your skincare regimen. Build up your tolerance slowly by applying it only 2-3 times a week, slowly working your way up to daily use over a period of 5-6 weeks.

Finally, don't expect immediate results. It takes a month (or a little more) of continuously using vitamin C until the benefits begin to show up. Trust us on this: your patience will pay off.

Good luck!