How to better grasp the benefits of Vitamin C for skincare - better to put it on the skin or just eat it?

Vitamin C is one of the most common ingredients in skincare products, but if you think its benefits for the skin are set in stone, we suggest you to read a little bit more about it!

Vitamin C is a very well known antioxidant, which seems to linger above all the hype in the cosmetic field. But are the Vitamin C benefits to your skin completely established and beyond dispute? Let us give you an unbiased update of the status of Vitamin C in the cosmetic field!

Do I really need to eat enough Vitamin C?

We've all been told to eat our fruits and vegetables, and one reason is get a dose of vitamins. Our bodies need Vitamin C to build blood vessels, muscle, and collagen, but we actually can't produce the vitamin ourselves - we can only get it from our diet. 

In fact, 14th century sailors became sick with scurvy when they lacked Vitamin C-rich foods. Their skin became fragile and their wounds healed slowly, showing that Vitamin C actually has an effect on skin. Today we know that Vitamin C accumulates in the skin and is shown to:

  • .Build collagen
  • .Prevent oxidative stress,
  • .Prevent photoaging and supporting skin response to UV damage,
  • .Prevent hyperpigmentation,
  • .Prevent wrinkle formation and skin sagging, in addition to
  • .Supporting skin hydration, barrier formation (which is so important, as we mentioned before here), decreasing inflammation and promoting tissue regeneration.

But how did scientists discover all these benefits of Vitamin C? It turns out that many Vitamin C studies were conducted on animals or in the lab, not on actual human subjects. That means there is still some dispute regarding the importance of Vitamin C supplementation. What studies did show is that the effects of Vitamin C are highly dependent on the person, which means that the Vitamin C supplementation is more effective in people with low or compromised Vitamin C content in the skin (e.g. smokers).

New evidence for Vitamin C rejuvenation effects

The skin appearance highly reflects its health state. During aging, the accumulation of aged cells (or zombie cells, as we use to call them) in the skin causes deterioration, the skin being the first organ to reveal visible signs of aging. In this scenario, the search of ingredients which prevent the accumulation of zombie cells is so important!

So here's the good news: even though Vitamin C is famous due to its antioxidant effects, new light suggests this molecule also decreases the amount of zombie cells in the skin! Well, this evidence was shown in mice, so, in this scenario, it is wise to be hopeful, but also to recognize that such effect must be further confirmed in humans.

No such evidence has been shown in the skin at this point, since the skincare field in general is not yet sensitive to the paramount roles of zombie cells in skin aging. But don't worry, OneSkin will soon test it and let you know about it!

Vitamin C: better to eat it or put it on the skin?

Even though experimental evidence shows that skin has an important amount of Vitamin C, its content in our skin decreases with aging, as well as after exposure to oxidant stress via pollutants or UV irradiation (2). The supplementation of such vitamin, especially along aging, is therefore generally seen as advisable. But what may be more effective: to supplement Vitamin C in our diet, or include it in our skincare routine?

Going through scientific studies, a few observations arise:

1. Vitamin C can be found in the skin in levels a little bit superior to blood or other body sites, being actively uptaken by the skin. So, if you have normal levels of Vitamin C in your body, your skin will probably accumulate a little bit more Vitamin C for herself. Furthermore, if you saturate your blood with Vitamin C (by eating it), you will probably saturate your skin with Vitamin C (1)!

2. Since the Vitamin C levels in the skin are directly influenced by its concentration in your whole body: if you don't eat Vitamin C, there is little use of putting it on skin, because your body will probably "steal" the skin Vitamin C and distribute to other sites!

3. But don't exaggerate when ingesting Vitamin C, because long-term use of oral Vitamin C in daily doses greater than 2,000 milligrams may increase the risk of significant side effects! As mentioned by the Mayo Clinic, the recommended daily amount of vitamin C for adult men is 90 milligrams and for adult women is 75 milligrams.

So eating is better than applying to the skin?

Well, since Vitamin C is constantly being degraded, especially in the more external layers of your skin, which are subjected to UV and oxidative stress, applying Vitamin C on skin is a very rapid way to keep your skin nourished, so eat your veggies to keep your body healthy, and apply Vitamin C to your skin at the same time!

(1) Pullar et al., The Roles of Vitamin C in Skin Health. Nutrients. 9, 866. Available from:
(2) Rhie et al., Aging- and photoaging-dependent changes of enzymic and nonenzymic antioxidants in the epidermis and dermis of human skin in vivo. J. Investig. Dermatol. 2001, 117, 1212-1217. Available from:

OneSkin Team

OneSkin Team

By being able to reprogram the "code of life", we will create new ways of living, and new ways of growing older. OneSkin is developing solutions to enable people to age better, healthier, and with better quality of life. Our mission is to promote people's access to effective anti-aging products, so they can feel and age at their best.

Jul 12, 2019

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