Skin Lightening Agent: Vitamin C

I was on a dermatologist’s instagram page and she was completely berating Vitamin C.

I know. I won’t cover old ground, but its generally agreed that Vitamin C (by which I mean L-Ascorbic Acid) does increase collagen content in the skin.

The flakiness of Vitamin C L-Ascorbic Acid continues with its skin- lightening properties. It is a skin lightener for sure, but the precise mechanism has not been figured out by scientists.

What is the current thinking of how L-Ascorbic Acid achieves skin lightening?

Vitamin C (L-Ascorbic Acid) does all of these:

Its an anti-oxidant – which by default means that its negating the effect of free Radicals caused by UV radiation. Our body responds by not producing the melanin it would in the absence of Vitamin C and therefore contributes to skin lightening.

It uses up the Copper ions at the site of Tyrosinase enzyme, the rate limiting enzyme involved in melanogenesis. Tyrosinase is Copper dependent and its absence means less Tyrosinase enzyme is produced by the body and therefore less melanin is produced. As a result skin lightens

As a reducing agent, it changes Dopaquinone back to DOPA and prevents the conversion to 5,6 – Dibyroxyindole – 2- Carboxylic Acid. This prevents the formation of Eumelanin, which is the dark / brown pigment.

Cons of using Vitamin C

L-Ascorbic Acid is not the best anti-oxidant out there – a study using Grape seed polyphenols on mice tumour cells in the lab demonstrates this. The scientists conducting this study found that both Vitamin C and Grape Seed Polyphenol down-regulated Tyrosinase activity, but Grape Seed Polypheonol was better at doing so. I’d add that the study used 50ug of Graph Seed Polyphenol and 1ug of Vitamin C…. But if the key takeaway is Vitamin C is not the world’s best anti-oxidant. That’s fine – I cannot disagree with that.

Unlike many other anti-oxidant, it is massively unstable. This poses a problem for manufacturers as it pretty much reacts as it pleases: Oxidation of LAA is triggered by high pH, high temperature, metal ions, ionization in solution, etc. the key to a stable product lies in its manufacturing process – you are looking for opaque packaging or a manufacturing process that excludes Oxygen.

Is it possible for a layperson to check these things? Pretty much “no” unless the manufacturer decides to tell you.

Au revoir

If you take one thing away from today’s blog let it be this: Vitamin C is a skin lightening ingredient.

My blogs on Vitamin C

Where the streets are only named after Vitamin C derivatives

Should I buy the highest percentage Vitamin C serum?

Should I use a topical Vitamin C product?

Source:

Chen X, Haniu A, Kashiwagi T, et al. The evaluation of the synergistic effect of 3-(2,4-dihydroxyphenyl)propionic acid and L-ascorbic acid on tyrosinase inhibition. Z Naturforsch C 2017;72:119–21

Chui H F et al, Inhibitory Effect of Grape Seed Polyphenol Extract and Vitamin C on Melanogenesis in Cultured B16-F1 Melanoma Cells Available online at Science Alert

Munoz-Munoz JL, Garcia-Molina F, Garcia-Ruiz PA, et al. Stereospecific inactivation of tyrosinase by L- and D-ascorbic acid. Biochim Biophys Acta 2009;1794:244–53. 

Sang Yeul Lee, Namhuk Baek & Tae-gyu Nam (2016) Natural, semisynthetic and synthetic tyrosinase inhibitors, Journal of Enzyme Inhibition and Medicinal Chemistry, 31:1, 1-13

Samaneh Zolghadri, Asieh Bahrami, Mahmud Tareq Hassan Khan, J. MunozMunoz, F. Garcia-Molina, F. Garcia-Canovas & Ali Akbar Saboury (2019) A comprehensive review
on tyrosinase inhibitors, Journal of Enzyme Inhibition and Medicinal Chemistry, 34:1, 279-309

Kamakshi R. Fairness via formulations: a review of cosmetic skin-lightening ingredients. J Cosmet Sci. 2012;63(1):43‐54.

Choi YK, Rho YK, Yoo KH, et al. Effects of vitamin C vs. multivitamin on melanogenesis: comparative study in vitro and in vivo. Int J Dermatol. 2010;49(2):218‐226.