Getting Nerdie With The Skin Nerd: Which Type of Vitamin C is Best for Skin?

The Skin NerdVitamin C, both when ingested and applied topically, is a powerhouse skingredient.

It can improve the appearance of redness by helping to strengthen capillary walls, it is a potent antioxidant, it aids with different processes in the formation of pigment in the skin and it is integral to the production of collagen within the skin (read more on vitamin C here).

Surely it can do all that regardless of putting extra on us or in us? Newsflash: as human beings, we don’t even make vitamin C… Guinea pigs don’t either, just FYI.

I was very confident in my knowledge of all things vitamin C. I’ve been trained for years in thinking that some forms are better than others.

However, I’ve had this tested in the last while as I see forms of vitamin C that I would’ve never even looked at twice on the street being used in fabulous formulations.

Newsflash: as human beings, we don’t even make vitamin C… Guinea pigs don’t either, just FYI.

I figured it was about time to break down some of the forms of vitamin C that you might not even be recognising on the back of bottles…

L-Ascorbic Acid or Ascorbic Acid

L-ascorbic acid is still my firm favourite form of vitamin C as I am wooed by the purity of it and by the fact that it has had the most research done on its effects in topical formulations.


– Purest form of vitamin C
– Very effective in high doses
– Boosts the skin’s own production of collagen


– At most effectiveness within 10 days of opening
– Difficult to stabilise in formulations… not a concern if you’re buying a vitamin C product, but good to know
– Expensive to put in products and usually expensive to find in highly effective percentages of it
– Can be degraded by exposure to light, hence why it’s often found in brown bottles

Some of my favourites that include ascorbic acid are the holy grail Skinceuticals CE Ferulic serum (€150,, much beloved by dermatologists and beauty editors worldwide, the Urban Veda Purifying Body (14.99, and Murad’s Essential-C Cleanser (€35.45,

Magnesium Ascorbyl Phosphate

Magnesium ascorbyl phosphate, or, aptly, MAP, doesn’t degrade in water like ascorbic acid does. It’s not quite as effective as ascorbic acid but it is perhaps more practical.


– Proven to turn into ascorbic acid in the skin
– Stable
– Increases skin’s hydration too
– Thought to boost the skin’s own production of collagen just like ascorbic acid
– Effective at stopping pigment from being created
– Isn’t thought to degrade due to light exposure
– Better for sensitive skin


– Not quite as effective as ascorbic acid

Some products that I know of that contain magnesium ascorbyl phosphate are the IMAGE Vital C Hydrating Waterburst (€56, and the Dermalogica MAP-15 Regenerator (€97,

Tetrahexyldecyl Ascorbate (also known as BV-OSC)

Tetrahexyldecyl ascorbate is great as it is oil-soluble. This oil-solubility means that it can penetrate into the skin easier as the skin is naturally covered in oils.


– Doesn’t degrade in light or water
– Oil-soluble so can penetrate into the skin easier
– Works well with other forms of vitamin C and may make them more effective
– Effective in lower concentrations than ascorbic acid
– Great for sensitive skin
– Boosts skin’s own production of collagen


– Still not as effective as ascorbic acid in general

You can find tetrahexyldecyl ascorbate in IMAGE’s Vital C Hydrating Anti-Ageing Serum (€71,, alongside ascorbic acid and MAP.

Ascorbyl Glucoside

Ascorbyl glucoside is a form of vitamin C combined with glucose, as you may be able to decipher from the name.


– Potent antioxidant
– Becomes ascorbic acid within the skin
– Works well when combined with brightening ingredient niacinamide
– Highly stable, even when exposed to light and water, and some say it can remain twice as effective compared to other forms of vitamin C


– Not the most effective form of vitamin C for improving pigment
– Not a lot is known definitively about how effective it is

Ascorbyl glucoside is used for its antioxidant properties in Avène’s A-Oxitive Antioxidant Defense Serum (€30.45, alongside pre-tocopheryl, a precursor to vitamin E that is also highly antioxidant.

Other things to note…

These are just some forms of vitamin C, this list is not the be all and end all – there are lots more out there that are effective too, such as sodium ascorbyl phosphate and ascorbyl palmitate.

One thing to note when it comes to vitamin C is that the different forms may suit the skin of some better than others.

Image via Pinterest

Ascorbic acid is actually known to cause spots for those prone to congestion but other different forms of vitamin C can be really beneficial for that type of skin.

One thing is for certain – vitamin C in general is just an indomitable anti-ageing ingredient but it is only good as the whole product that it is in!

Jennifer Rock is the founder of The Skin Nerd online skin consultancy and online cosmeceutical skincare store. If you’re interested in having a consultation with one of her expert Nerdettes, click here for more information.

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