Do you have oily acne-prone skin that can break out if you so much as sniff a new skincare product? Are you looking to incorporate a vitamin C serum into your skincare routine but worried that it will break you out? Is vitamin C good for acne-prone skin? Or does vitamin C serum cause acne?
Let’s explore the research behind vitamin C serums in order to answer these questions.
But first, why should you consider introducing a vitamin C serum into your routine in the first place?
Vitamin C Serum Benefits For Skin
Vitamin C is the most abundant antioxidant in your skin and is essential for the production of collagen.
Antioxidants, such as vitamin C, co-exist to protect your skin from free radicals, including reactive oxygen species (ROS), that are formed when your skin is exposed to ultraviolet (UV) radiation.
Free radicals cause changes to cellular DNA and proteins as well as causing inflammation. These changes result in the destruction of collagen and elastin and can potentially cause skin cancer.
Unfortunately, even with the correct application, sunscreens can only block 55% of the free radicals produced by UV exposure.
This means that topical antioxidants should be used in addition to sunscreens to provide protection against free radical damage. In fact, a number of sunscreens are formulated with antioxidants for this exact reason.
Even with extremely high doses of oral vitamin C, only a small amount will be available for your skin to use. For this reason, topical application of cosmetics containing vitamin C, such as vitamin C serums, are required to maintain sufficient skin levels of vitamin C.
So, the number one reason that you should use a vitamin C serum is for its potent antioxidant effects which can help prevent premature skin aging and reduce your risk of skin cancer.
Vitamin C’s role in collagen synthesis means that it also has a more general anti-aging effect as well.
Collagen production decreases as you naturally age and the rate at which it decreases is drastically enhanced when your skin is regularly exposed to UV radiation.
Topical vitamin C formulations have also been shown to be as effective as hydroquinone therapy at reducing hyperpigmentation. It does this by reducing the activity of the main enzyme involved in melanin production, tyrosinase.
Basically, you may be considering introducing a vitamin C serum into your skincare routine if:
- You want to help protect your skin against UV damage and enhance the protective effects of your sunscreen.
- You want to boost collagen production in order to improve fine lines and wrinkles.
- You want to prevent the breakdown of existing collagen.
- You want to reduce hyperpigmentation.
But does vitamin C help acne or, more importantly, does vitamin c serum cause acne?
What Is Acne, And What Causes It?
Acne is an inflammatory skin condition characterized by blocked and inflamed hair follicles (pores) and oil glands which results in pimples. It is caused by multiple overlapping factors:
- Hormones cause your oil glands to overproduce oil.
- Your rate of skin cell turnover is reduced causing a build-up of dead skin cells on the surface of your skin.
- The dead skin cells block your hair follicle and trap the oil inside.
- A bacteria called p-acnes (recently reclassified to c.acnes) lives within your oil glands, uses your oil as energy, and, when there is an overproduction of oil, rapidly multiply.
- The increase in bacteria causes an inflammatory response and your body sends its white blood cells to ‘fight’ the infection.
The main causes of acne are, therefore:
- An overproduction of oil.
- A build-up of dead skin cells.
- c-acnes bacteria.
- Inflammation/Immune response
One of the ways we can work out whether vitamin C is good for acne-prone skin or whether vitamin C serum causes acne is to look at how vitamin C affects oil production, skin cell turnover, bacteria growth, and inflammation.
Can You Have Too Much Antioxidant?
The biggest criticism regarding vitamin C serums for acne-prone skin is down to their potent antioxidant effects.
As mentioned earlier, antioxidants help to protect your skin from free radical damage, however, some research suggests that small amounts of free radicals are good for you.
It turns out that it may not be as simple as ROS = bad, Antioxidants = good.
The cells in your body seem to require a specific balance of both antioxidants and ROS in order to function optimally.
For example, multiple research studies have demonstrated that cancer cells have a greater level of ROS than normal cells – highlighting the role of ROS in tumor formation. Furthermore, higher antioxidant levels in cells are associated with lower ROS levels.
However, it appears that ROS at high levels can slow tumor growth and destroy cancer cells but the process by which they do so is prevented by antioxidants.
This ROS-Antioxidant balance also has implications for acne-prone skin. This is because there is some evidence to suggest that ROS have antimicrobial effects.
In theory, this would mean that ROS may actually help acne by preventing the overgrowth of bacteria.
If this were true, then a potent antioxidant serum, such as a vitamin C serum, may actually make acne worse by neutralizing the ROS that are keeping the acne-causing bacteria at bay.
However, this research is very limited and it is not known whether the c-acnes bacteria is affected by ROS-antimicrobial activity (research seems to be focussed on the Salmonella enterica bacteria).
Furthermore, if ROS were found to have antimicrobial effects on the c-acnes bacteria, it is not known what level of antioxidants would unbalance the ROS-Antioxidant equilibrium in order to affect this.
Anti-Inflammatory Effect of Vitamin C
Plenty of research has demonstrated that Vitamin C has excellent anti-inflammatory effects. For example, vitamin C can reduce the redness and inflammation associated with sunburn and laser resurfacing.
Research has also shown that vitamin C can reduce facial redness by 21% after 6 weeks of daily use which suggests that it may help improve the appearance of acne.
There is relatively little research specifically investigating the effect of topical vitamin C on acne. However, one study found that 5% sodium-L-ascorbyl-2-phosphate (SAP), a vitamin C derivative, reduced the number of acne lesions in 61-71% of subjects.
The authors of this study suggested two different mechanisms by which the SAP improved acne – both of which can be explained by its antioxidant effects:
- Individuals with acne have a higher concentration of skin surface lipids that, when oxidized, are highly comedogenic (pore-blocking) and antioxidants may prevent this.
- Common antibiotic treatments for acne, such as tetracycline, doxycycline, and erythromycin have demonstrated antioxidant effects by reducing ROS.
Altogether, this suggests that antioxidants may be an effective treatment for acne, both by reducing inflammation and by targeting ROS.
As vitamin C is one of the most potent antioxidants and is essential for skin health, it is particularly highlighted as a potential acne treatment.
How To Choose And Use Vitamin C Serums
There are a number of different active forms of vitamin C but the most biologically active and well-studied is L-ascorbic acid.
However, L-ascorbic acid is unstable and struggles to penetrate your skin. This means that it needs to be formulated in a very specific way.
Vitamin C works best at a concentration of 8-20%.
Concentrations of more than 20% offer no increase in effectiveness but may increase irritation, while concentrations of less than 8% are too low to offer any significant antioxidant effects.
However, lower concentrations may be effective for inflammatory skin conditions such as acne (the study mentioned earlier used 5% SAP)
The Best Vitamin C Serum
Arguably the ‘holy grail’ of vitamin C serums is SkinCeuticals C E Ferulic. The addition of ferulic acid to L-ascorbic acid improves the stability of the vitamin C serum and reduces the acidity to a pH of below 3.5.
In fact, this topical vitamin C formulation was the first to be clinically proven.
For those of you looking to actively treat acne, look for vitamin C serums with sodium ascorbyl phosphate, as this was the form of vitamin C used in the research study mentioned earlier.
Does Vitamin C Serum Cause Acne?
It is unlikely that vitamin C serums will cause acne. There is some evidence to suggest that using a vitamin C serum may make your skin more vulnerable to bacteria. However, this research is complex and is based on the observation that low levels of ROS may actually have protective effects, including antimicrobial activity.
Since antioxidants, such as vitamin C, neutralize ROS, they may inhibit these protective effects and could cause an increase in acne-causing bacteria.
Overall, though, there is not enough evidence to support the claims that vitamin C serums can cause acne.
Is Vitamin C Good For Acne Prone Skin?
Vitamin C has potent anti-inflammatory effects, mainly due to its antioxidant activity. As one of the main causes of acne is inflammation, it is highly likely that vitamin C serums can help improve the appearance of acne.
In fact, some research has demonstrated that topical vitamin C can reduce the number of acne lesions after 6 weeks of daily use.
In addition, vitamin C can improve facial redness which is often a concern in acne and post-inflammatory erythema. However, other antioxidant serums have more evidence to back up their anti-acne effects and may be a better investment.
What Should I Look For In A Vitamin C Serum?
The ideal vitamin C serum would contain L-ascorbic acid, have a concentration of 8-20%, and a pH of less than 3.5.
In addition, vitamin C serums seem to be more effective with the addition of vitamin E and ferulic acid.