Vitamin C for Sensitive Skin: Ascorbic Acid or Derivatives?

Skincare for rosacea, even with vitamin C, is individualized. It can reduce skin stress. However, only a few people with rosacea tolerate (high-dose) ascorbic acid.
If you have rosacea and want to use vitamin C, you should always opt for vitamin C derivatives. And make sure you use vitamin C as a standalone product. Many creams simply have vitamin C added as an ingredient. If you don't notice this when shopping, you can easily end up using vitamin C multiple times and potentially experiencing redness.

There are several vitamin C derivatives, which are derivatives of pure ascorbic acid. Under certain circumstances, these can be converted into ascorbic acid.

Vitamin C derivatives are much better tolerated than pure ascorbic acid. However, their effectiveness is not nearly as well-documented as that of pure vitamin C. For derivatives, laboratory studies (in vitro) predominate. Comprehensive human studies (in vivo) are not always available. Such studies would be crucial for understanding the effects of a vitamin C derivative.

First, it would need to be proven that the vitamin C derivative is absorbed into the skin. Furthermore, it would need to be demonstrated that the vitamin C derivative can be converted into pure ascorbic acid within the skin. And then it's questionable whether the amount actually converted is sufficient. In most cases, significantly less ascorbic acid is present in the skin than with pure ascorbic acid products. This is because the amount converted into ascorbic acid varies from derivative to derivative. And this crucial point must be addressed. Only if it is absorbed into the skin and a certain amount is converted can a well-tolerated derivative come close to the effectiveness of ascorbic acid.

Furthermore, it's difficult to find studies on derivatives that are independent of manufacturers. Nevertheless, it's worthwhile to include these results in your evaluation. You should simply be aware that the effectiveness of derivatives is difficult to verify. There are advantages and disadvantages to each. Depending on your goal, it makes sense to choose one or more vitamin C derivatives or combinations.

Sodium ascorbyl phosphate is a very stable vitamin C derivative . It's particularly effective for combination and very oily skin. A 1% concentration of sodium ascorbyl phosphate combats acne bacteria, while a 5% concentration reduces inflammation associated with acne vulgaris. Its effects are comparable to 5% benzoyl peroxide . If you're considering using this vitamin C derivative for acne, discuss it with your dermatologist. It might be a beneficial addition to other treatments in your case. Human studies have also demonstrated the strong antioxidant properties of sodium ascorbyl phosphate. Laboratory studies have confirmed its collagen-strengthening properties. Unfortunately, sodium ascorbyl phosphate is poorly absorbed by the skin. Furthermore, there's no data on its sufficient conversion to ascorbic acid. Despite this, it's available in numerous products. If you suffer from frequent breakouts or acne, it might be worth a try.

This is the most stable vitamin C derivative . It works well against hyperpigmentation and is also suitable for sensitive skin. However, it has the disadvantage of not being as strong an antioxidant. You'll primarily find it in water-based serums or lotions, as magnesium ascorbyl phosphate is only water-soluble. A good option if you're just starting out. However, it won't be as effective as other derivatives.

Ascorbyl glucoside is also a very stable derivative . Laboratory studies have proven that ascorbyl glucoside can indeed penetrate the skin. However, studies with real people are still needed. Nevertheless, human studies have already demonstrated that it can be converted into effective ascorbic acid in the skin. Ascorbyl glucoside has antioxidant properties , fades hyperpigmentation , and strengthens collagen fibers . This makes it one of the most effective of the well-known derivatives currently available.

If only this one vitamin C derivative is present in a vitamin C product, you can save your money . Why?

Ascorbyl palmitate is not particularly stable . No increase in ascorbic acid levels could be detected in the skin after its use. While it is oil-soluble, and oils can help vitamin C penetrate the skin more effectively, you should n't expect too much from this derivative in terms of efficacy. It likely requires a very large amount to produce any noticeable effect, and even that would need to be further investigated. In the small quantities used in some serums on the market, it is ineffective against hyperpigmentation. Therefore, there are far more promising derivatives than ascorbyl palmitate.

Tetrahexyldecyl ascorbate, also known as ascorbyl tetraisopalmitate, is a vitamin C derivative. Both names are used interchangeably. Either may appear in the INCI list . This vitamin C derivative is oil-soluble and extremely stable . However, its oil-soluble nature can also be a disadvantage for certain skin types, as the product must always contain oil. Therefore, serums containing tetrahexyldecyl ascorbate may be too rich and could promote breakouts.

It penetrates the skin and is converted into pure ascorbic acid. Furthermore, it appears to offer all the positive effects of vitamin C. It can lighten hyperpigmentation, strengthen collagen , and has a strong antioxidant effect. So far, these results are based solely on laboratory studies. There is only one very small human study with positive results, and this study tested a product that also contained pure ascorbic acid. Therefore, it is questionable whether the ascorbic acid itself contributed to the positive effects. Consequently, further relevant studies are still needed. A combination with other derivatives would be the best option.

Nevertheless, tetrahexyldecyl ascorbate, or ascorbyl tetraisopalmitate, remains a truly stable vitamin C derivative. And in any case, it is better tolerated than ascorbic acid. Therefore, it might be an option for sensitive skin if pure vitamin C products don't work for you.

Ethyl ascorbic acid is a very stable derivative that is soluble in both oil and water.

According to animal studies, this derivative is likely more effective than ascorbyl glucoside. It has been shown to be absorbed into the skin and converted into ascorbic acid. In this process, significantly more ascorbic acid is produced than with other derivatives. This makes ethyl ascorbic acid potent and very effective . Like tetrahexyldecyl ascorbate, ethyl ascorbic acid also has strong antioxidant properties and strengthens collagen . Ethyl ascorbic acid's strength clearly lies in its effectiveness against hyperpigmentation . Little is known about the tolerability of ascorbic acid. It is certainly a more potent active ingredient compared to other derivatives. Therefore, it is possible that sensitive skin may not tolerate it as well.