What are the benefits of topical Vitamin C?

Vitamin C is a very important vitamin that should be consumed on a regular basis to promote optimal health outcomes and prevent scurvy, which is a severe vitamin C deficiency.  However, vitamin C in various forms can be added to skincare products for a variety of reasons.  What is topical vitamin C, what is it used for, and what are the potential benefits and side effects?

What is topical vitamin C?

L-ascorbic acid, also known as vitamin C, is an essential vitamin that contributes to many important bodily functions and biochemical pathways.  Vitamin C is typically found in fruits and vegetables, and it needs to be consumed on a regular basis because it cannot be made by the body. 

Vitamin C from food and supplements performs a variety of roles:

• It is needed for the synthesis of collagen, which is a protein that helps form skin, bones, muscles, hair, and connective tissue.¹ 
• Vitamin C acts as a powerful antioxidant by neutralizing free radicals that could contribute to oxidative stress later in life.¹  
• Vitamin C also helps enhance the absorption of nonheme iron, which is the form of iron found in plant-based foods.¹

Vitamin C in skincare

Since vitamin C is essential for collagen production and acts as an antioxidant, it might theoretically contribute to skin health and appearance.  However, vitamin C only acts on skin when applied topically to the area; its active form, L-ascorbic acid, is not taken up by the skin in sufficient amounts when consumed orally.² 

Some research has been done on the effects of topical vitamin C in skincare, and some of the findings suggest a variety of potential benefits that should be investigated with further research.

Topical Vitamin C for photoaging

Skin aging naturally occurs over time, and it is characterized by a variety of changes that can result in a loss in skin plumpness and thickness as well as the onset of fine lines and wrinkles.³  Photoaging refers to premature skin aging related to UV exposure; excess UV radiation can impact skin integrity and increase the risk of a variety of consequences down the road, including skin cancers.⁴ 

Topical vitamin C could potentially help reduce and prevent the signs of photoaging through a few different mechanisms. 

• Vitamin C is needed for the synthesis of collagen, which is important for skin health and tends to decrease with age. Some research suggests that vitamin C could help promote collagen synthesis when applied topically.^5,6  One study found that, when applied to human skin samples, a vitamin C and squalane compound was associated with increased epidermal thickness and collagen production.⁵  More research is needed to determine the effectiveness of topical vitamin C in improving the maintenance and synthesis of dermal collagen.
• As an antioxidant, vitamin C could potentially neutralize the reactive oxygen species that occur as a result of environmental stress, such as UV radiation exposure.⁷  These reactive oxygen species, which are unstable molecules, could promote a variety of changes that can lead to accelerated skin aging.⁸  Vitamin C can also regenerate the active form of vitamin E, which is another antioxidant that could potentially have a variety of beneficial effects for the skin; however, more research is needed to establish these benefits.^6,9 
• Some evidence suggests that antioxidants such as vitamin C may have a photoprotective effect.  One study found that the use of a 10% topical vitamin C (L-ascorbic acid) serum in pig skin exposed to UV-B radiation was associated with a 40% reduction in sunburn cells.^{10, 11.} Another study found that human participants exposed to UV radiation using a 10% vitamin C serum exhibited less erythema than the participants using a control serum.¹¹  More research is needed to determine the effectiveness of Vitamin C in photoprotection as well as determine the mechanism of how it occurs.

Topical vitamin C for hyperpigmentation

Some research suggests that topical vitamin C could be helpful in decreasing hyperpigmentation.  L-ascorbic acid, which is the active form of vitamin C, inhibits the action of the tyrosinase enzyme – the enzyme that converts the amino acid tyrosine into melanin, which is the pigment that the skin produces to protect itself.²  For example, 40 patients with melasma in one clinical trial had a reduction in melasma symptoms after using a 25% L-ascorbic acid topical product for 16 weeks.¹² 

Other possible applications of vitamin C may include its use in the treatment of post-inflammatory hyperpigmentation, which is the hyperpigmentation that can occur after inflammation, skin injury, or certain skin treatments.¹³ 

Vitamin C may have an anti-inflammatory effect, which could theoretically help prevent the skin’s hyperpigmentation response to injury.¹⁴  However, this is not currently well-studied, and more research is needed to establish the effects of vitamin C on post-inflammatory hyperpigmentation.

Vitamin C also may be challenging to formulate in skincare products; L-ascorbic acid is not generally stable in water, so current areas of vitamin C research include finding out effective ways to deliver the potential benefits of vitamin C in skincare products.¹⁴ 

What are the side effects of topical vitamin C?

Vitamin C is generally thought to have a good safety profile, and it tends to react well with other active skincare ingredients such as tretinoin, alpha-hydroxy acids, and other antioxidants.¹⁴  Some relatively rare side effects may include mild skin stinging, dryness, and redness.¹⁴  Some forms of vitamin C may also stain clothes and give the skin a yellow tint.¹⁴ 

It is important to seek medical help if you experience any side effects that you are concerned about when using skincare products that contain vitamin C.  Additionally, seek medical help immediately if you experience signs of an allergic reaction after using topical vitamin C, such as chest tightness, hives, or swelling of the face, mouth, or throat.

Although there is a possibility of vitamin C having a photoprotective effect, it is still important to protect yourself from UV radiation as with any other skincare routine.  This can be done by limiting sun exposure, wearing sun-protective clothing, and regularly applying a broad-spectrum sunscreen that protects against both UVA and UVB radiation.

This article is not medical advice, and it is not intended to prescribe, diagnose, or promote specific treatments for any condition. Consult your doctor, dermatologist, or other qualified healthcare provider for your unique skin needs.

References

1. National Institutes of Health Office of Dietary Supplements (2021, March 26). Vitamin C: Fact Sheet for Health Professionals. U.S. Department of Health & Human Services. Accessed 2021, June 29, from https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/#en4
2. Ravetti, S., Clemente, C., Brignone, S., et al (2019). Ascorbic acid in Skin Health. Cosmetics 6(4): 58. Doi: 10.3390/cosmetics6040058
3. Poon, F., Kang, S., Chien, A.L. (2014). Mechanisms and treatment of photoaging. Photodermatology, Photoimmunology & Photomedicine 31(2): 65-74. Doi: 10.1111/phpp.12145.
4. Gromkowska-Kepka, K.J., Puscion-Jakubik, A., Markiewicz-Zukowska, R., et al (2021). Journal of Cosmetic Dermatology. Doi: 10.1111/jocd.14033
5. Gref, R., Delomenie, C., Maksimenko, E., et al (2020, October 9). Vitamin C-squalene bioconjugate promotes epidermal thickening and collagen production in human skin. Scientific Reports 10(16883). Doi: 10.1038/s41598-020-72704-1.
6. Al-Niaimi, F., Chiang, N.Y. (2017). Topical Vitamin C and the Skin: Mechanism of Action and Clinical Applications. J Clin Aesthet Dermatol 10(7): 14-17. Accessed 2021, July 1, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5605218/#B3
7. Farris, P.K. (2006). Topical vitamin C: a useful agent for treating photoaging and other dermatologic conditions. Dermatologic Surgery 31(s1): 814-818. Doi: 10.1111/j.1524-4725.2005.31725.
8. Rinnerthaler, M., Mischof, J., Streubel, M.K. (2015). Oxidative stress in aging human skin. Biomolecules 5(2): 545-589. Doi: 10.3390/biom5020545.
9. Abid Keen, M., Hassan, I. (2016). Vitamin E in dermatology. Indian Dermatol Online J 7(4): 311-315. Doi: 10.4103/2229-5178.185494.
10. Eberlein-Konig, B., Ring, J. (2005). Relevance of vitamins C and E in cutaneous photoprotection. Journal of Cosmetic Dermatology 4(1): 4-9. Doi: 10.1111/j.1473-2165.2005.00151.x
11. Darr, D., Combs, S., Dunston, S. (1992). Topical vitamin C protects porcine skin from ultraviolet radiation-induced damage. British Journal of Dermatology 127(3): 247-253.
12. Hwang, S., Oh, D., Lee, D., et al (2009, March). Clinical efficacy of 25% L-ascorbic acid (C’ensil) in the treatment of melasma. Journal of Cutaneous Medicine and Surgery. Doi: 10.2310/7750.2008.07092.
13. Davis, E.C., Callender, V.D. (2010). Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. J Clin Aesthet Dermatol 3(7): 20-31. Accessed 2021, July 1, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921758/
14. Telang, P.S. (2013). Vitamin C in dermatology. Indian Dermatology Online Journal 4(2): 143-146. Doi: 10.4103/2229-5178.110593.
15. Image by 4924546 from Pixabay