The only skincare guide you'll ever need for using vitamin C

If all the world’s a stage and we’re merely players, then vitamin C is the MVP. Second only perhaps to retinoids/retinol when it comes to being both a fan favourite as well as beloved by experts and backed by research and studies. But you know what they say about great power. That amount of responsibility can make anyone crack. Vitamin C in its purest form of ascorbic acid (AA) or L-ascorbic acid (L-AA) is like that one know-it-all high school overachiever we’ve all had in our class. They have the talent and skill to back up why they’re the teacher’s favourite, and everyone wants to them on group projects, but they come with a risk of cracking under the pressure of high expectations. Unstable, difficult to work with and quick to degrade into a hot mess.

Like a beginner chef’s free use of garam masala in every dish, you’ll see vitamin C sprinkled into every third product hitting the shelves. In our burgeoning billion-dollar beauty market, vitamin C is not just a trend but a staple. Especially in a culture obsessed with lightening and brightening our skin to strip the melanin away.

But given the sheer variety of options available in the market, talks of derivatives and product recommendations strewn across social media and even DIYs videos proclaiming wondrous effects, it can get a bit overwhelming to find what will work best for your skin.

Not all forms of vitamin C are the same when it comes to skincare and with the help of experts, we’ve created a handy guide for all you need to know about the MVP of skincare. Including its benefits and the most effective ways to use it without irritating your skin.

The vitamin C skincare resume

Collagen production

Dr Karen Burke, dermatologist and research scientist, says that vitamin c is essential for collagen synthesis. The internet’s favourite cosmetic chemist Michelle Wong AKA Lab Muffin Beauty Science explains the science of it all. She says, “It’s involved in making collagen and crosslinking it so that it makes a nice, firm solid network. Some of the enzymes involved in this, lysyl hydroxylase and prolyl hydroxylase, need vitamin C to work. Vitamin C may also be able to block the action of matrix metalloproteinase-1 (MMP-1), an enzyme that breaks down collagen in the skin.”

As our collagen production slow and elastin breaks down with age, adding vitamin C to our routine can be beneficial as a preventative product for aggravated signs of skin ageing.

Reduction in Hyperpigmentation

You would have seen advertisements for vitamin C products where dark spots on a woman’s face magically disappear. Ascorbic acid disrupts the working of the enzyme tyrosinase which is responsible for melanin production, the pigment that gives us the beautiful colour of our skin. Overproduction of melanin causes hyperpigmentation, which doesn’t match our skin tone.

So whether you’re struggling with marks left over from acne, sun spots and UV damage or melasma, “the sooner you add a vitamin C product to your routine, the quicker the pigmentation can be reversed before it gets graver,” says dermatologist Dr Jayesh Shashtri.

Added sun protection

A vitamin C product is by no means a replacement for proper sun protection – sunscreen, wide-brimmed hats and UV protective sunglasses. However, as Wong says, it “acts like an antioxidant that mops up the damage that UV does inside your skin.”

“One of the big reasons that UV is bad for skin is that it produces free radicals. They’re basically really reactive substances that smash into lots of different parts of your skin causing generalised damage, sort of like a bull in a china shop.” Antioxidants like the potent ascorbic acid can absorb this damage and reduce its impact on the skin.

The best way to use it in a routine

Vitamin C comes in many forms, but the most studied is ascorbic acid. It also happens to be the most irritating because of the low pH balance that it needs to be able to work its way into our skin. That is to say, the acidic environment it creates can make the skin feel sensitive, irritated and cause other products to sting when you apply them.

It also oxidises quickly when exposed to air or sunlight. You’ll notice the smell starting to get a bit funky and the serum’s colour shifting from clear to yellowish, orange and then, brown.

Ascorbic acid breaks down into dehydroascorbic acid, becoming inactive. There’s nothing wrong with using the serum when it starts changing colour but it is going to become more ineffective and has a higher chance of staining your skin the darker it gets, that is, the more it oxidises.

That is why it is best to use ascorbic acid products that come in darker bottles instead of clear glass and have a pump rather than a dropper. This reduces its exposure to sunlight and oxygen.

When it comes to reaping its benefits, you want to be between 10% and 20% concentration of ascorbic acid.

“A lower percentage at 8% or 5% will also give you the brightness or glow you’re looking for and if your skin is not used to active ingredients, this is a better place to start before working your way up,” says Shashtri. “Having a higher percentage doesn’t necessarily mean that it’ll work better or faster. That’s a myth. In fact, a high percentage can also irritate your skin and cause damage.”

The debate as to when in the day you should use it is ongoing. Some experts recommend starting your day with vitamin C so it can tag-team with your sunscreen and support its work against UV damage. Others believe it has a slow release and can last on the skin for more than 24 hours, so even if you apply it at night, it’s doing the heavy lifting in your skin through the next day.

Shashtri suggests that people using a high concentration of ascorbic acid apply it at night, where you’ll get the anti-ageing benefits and let your skin rest through the night when it may be irritated and raw.

Making it work with other products in your routine

Vitamin C became notorious for being a no-go to use with another skincare gem, niacinamide. You may have seen videos and posts waving red flags, but turns out, it’s not such a toxic couple after all.

Niacinamide is a fantastic anti-inflammatory ingredient that, like vitamin C, is effective at reducing hyperpigmentation. It was believed that they would cancel each other out when used at the same time or in the same product. But more current research has debunked the claim, citing that the possible irritation people have experienced using them together is more likely caused by the acidic vitamin C product itself.

Stephen Alain Ko, a cosmetic and skincare formulator, has written about this extensively and says, “Mixing niacinamide and ascorbic acid turns the two clear solutions into a yellow colour, but this isn’t the same yellow colour that appears when ascorbic acid is oxidised into dehydroascorbic acid.”

The experts concur that vitamin C can work well with most ingredients. They advise you to apply it early in your routine so it’s close to your skin without having to work through the barriers of other products. However, two ingredients they say you should avoid using in the same routine is benzoyl peroxide and products with copper ions (blue copper products).

“For beginners, I would suggest making vitamin C the one active in your routine. So if you are using exfoliating ingredients like glycolic acid, lactic acid and salicylic acid as well, then divide it between day and night or on different days so your skin doesn’t get overloaded,” adds Shashtri.

The real deal with vitamin C derivatives

When it comes to vitamin C, the gold standard has been set in the formula of vitamin C combined with vitamin E and ferulic acid. The Destiny’s Child of antioxidants was intensively studied by Dr Sheldon Pinnel for its effect on the skin. He patented the trio’s formulation, which his son later bottled and shared with consumers through his company Skinceuticals. The now-iconic SkinCeuticals C E Ferulic serum is as good as it gets but getting it in India can be pricey. 

Vitamin C is most effective in the form of ascorbic acid, but it’s at its most volatile as well.

Given the instability of vitamin C, there are several vitamin C derivatives that cosmetics formulators started to work with. The derivatives are more stable while retaining some of the efficacy of ascorbic acid, depending on its formulation. Studies haven’t been conclusive regarding the benefits of derivatives on human skin. As dermatologist Dr Jenny Liu writes, “One study may show benefit of a derivative, while another demonstrates no efficacy. This inherently speaks to the challenges of manufacturing L-ascorbic acid, as the formulation is everything.”

Dr Jennifer Herrmann says, “These derivatives are not pure vitamin C, rather they are combined with other ingredients, which might help to keep the vitamin C stable. So when these derivatives come in contact with the skin, they release the pure vitamin C onto the skin.” 

If a product using vitamin C derivative cites a value of 15%, the actual amount of vitamin C being delivered to the skin may only be 10%. The product has to work extra hard to convert to ascorbic acid on the skin.

Dermatologist and hair transplant surgeon Dr Ratisha Kumar says that while ascorbic acid gives us all these benefits, the derivatives may not be able to live up to all of them at the same time or as fast. However, with a little patience, you can still get the benefits of ascorbic acid, without the irritation or product turning brown every three months. You need to pick and choose which derivative to opt for based on your skin type. 

She breaks down some of the most commonly used derivatives:

Sodium and/or magnesium ascorbyl phosphate (SAP and MAP) – Better suited for acne-prone skin as it’s proven in some studies to help in the treatment of acne. It also provides overall brightening and is gentle on the skin while being effective, a good place for beginners to start.

Tetrahexyldecyl ascorbate (THD) – More fatty in nature, you’ll find it in creamy or oil-based formulations so it’s better for people with dry skin. It can be hydrating and moisturising, and has been found to be beneficial at targeting hyperpigmentation spot treatment.

Ascorbyl glucoside – It hasn’t shown great results in brightening but has a similar collagen-boosting ability that ascorbic acid does. It’s a good addition to a routine for mature skin.

Ethyl Ascorbic Acid (EAA) – This type of vitamin C is both stable in water and oil and is most commonly used nowadays because it’s non-irritating. Compared to other derivatives, this has shown the most promise when it comes to penetrating the skin. If you want brightening and anti-inflammatory benefits, this is one to opt for.

Tweak recommends: Minimalist Ethyl Ascorbic Acid 10% + Acetyl Glucosamine 1% serum, ₹695, Plum Vitamin C Face Serum with Mandarin (15% EAA), ₹467 on sale, and Sesderma C-Vit Liposomal Serum, ₹2,850

It’s not all topical

When it comes to overall collagen production, nutrition is more important than what we apply to our skin, according to Shastri. A diet rich in citrus fruits like oranges and limes, antioxidant-rich berries like amla and veggies like tomatoes, cantaloupes and bell peppers bumps up your vitamin C levels. Bollywood’s favourite health expert, Dr Jewel Gamadia says that vitamin C deficiency can cause bleeding gums, weaker immunity, scurvy or low iron absorption from food. 

Low vitamin C can aggravate skin conditions like atopic dermatitis, cause you to develop keratosis pilaris and cause dull skin and skin damage by oxidative stress.

While science is working hard to make products that offset the repercussions of our poor lifestyle choices, we need to keep our intrinsic vitamin levels up to ensure that all the heavy lifting isn’t left to our skincare.