What is Ferulic Acid?

Ferulic acid, with the chemical name 3-methoxy-4-hydroxycinnamic acid and the chemical formula C10H10O4, is a phenolic acid extracted from cinnamic acid. Ferulic acid gets its name from the Ferula plants, which belong to the 170 species of herbaceous plants in the Apiaceae family of the Angiospermae division. Ferulic acid exists in many plants, including grains (oats, rye, corn), the bark of some trees (pine, fir), fruits (rhubarb, walnuts), vegetables (spinach), and coffee. The ferulic acid produced by Xi'an Green Spring uses rice bran as the raw material and obtains high-purity ferulic acid through a refining process.

(Figure 1: Ferulic Acid Production Process)

Ferulic acid is widely used in pharmaceuticals, pesticides, health products, cosmetic raw materials, and food additives due to its strong antioxidant activity and preservative effect.

The Efficacy of Ferulic Acid

Ferulic acid is favored by the cosmetics industry because of its strong oxidation resistance and its ability to inhibit the activity of tyrosinase. Some researchers have indicated that in addition to being able to inhibit reactive oxygen species, scavenge free radicals, and suppress lipid peroxidation, ferulic acid can also chelate protonated metal ions (such as Cu(II) or Fe(II)) and inhibit the activity of enzymes related to free radicals.

Ferulic acid in cosmetics can also be used as a whitening agent and a skin photoprotective agent. Ferulic acid has a good ultraviolet absorption near 290-330nm, and the ultraviolet rays in the wavelength range of 305-310nm are the most likely to induce skin spots. Therefore, ferulic acid can inhibit skin aging, reduce the formation of spots, and whiten the skin, so it is widely used in cosmetics. Ferulic acid contains a highly conjugated system and has a strong absorption of ultraviolet rays, and can effectively capture oxygen-containing free radicals, such as ·OH. Due to its numerous resonance conformations, its action time is long. Adding 5.15mmol/L can inhibit lipid oxidation by 70.9%, which has the same activity as superoxide dismutase. Ferulic acid is an effective photostabilizer and has an anti-phototoxic effect, and is widely used in sunscreen products; Ferulic acid can form esters with polyhydroxy compounds to improve water solubility, such as glycerol, cyclodextrin esters, etc., and its antioxidant and ultraviolet absorption functions remain unchanged;

In addition, the antibacterial and anti-inflammatory effects of ferulic acid have also been verified in some studies. Research shows that ferulic acid also has the effects of stimulating hair growth and darkening hair, so it is also applied in hair washing and hair care products.

Diversified Applications - Composite Formulas of Ferulic Acid with Other Ingredients

Although the antioxidant effect of a single ferulic acid is also quite excellent, it still has some inevitable problems. For example, in terms of stability, ferulic acid is chemically active and easily oxidized, and it will also degrade due to the influence of pH value and temperature. Therefore, in order to enhance the activity of the ingredients and the stability of the formula, ferulic acid is often used in combination with other ingredients, and some compound ingredient combinations have even become classics.

Stable Formula: The "CEF" Combination

Among the many combinations of ferulic acid, the "CEF" combination is the most famous. In 2005, researchers from Duke University in the United States found that ferulic acid can improve the chemical stability of vitamins (C + E). At the same time, applying a solution composed of 0.5% ferulic acid, 15% vitamin C, and 1% vitamin E locally on the skin can increase the skin photoprotection effect by 4-8 times under sunlight exposure. As a stable antioxidant combination, the combined use of the three has also enhanced their efficacy. With the release of this research result, the SkinCeuticals CEF Serum was officially launched and has since become a classic anti-aging essence that has been selling well to this day. In the SkinCeuticals Phloretin CF Serum, the combination of vitamin C + ferulic acid + phloretin is used. SkinCeuticals' research has found that phloretin is not only an effective antioxidant but also can increase the stability of vitamin C and ferulic acid in the formula, as well as the photoprotective effect on the skin.

In addition to SkinCeuticals, many other brands also follow the "CEF" combination. For example, Perricone MD, a functional skin care brand established by the dermatologist Nicholas Perricone, M.D., launched a Vitamin C + Ferulic Acid Brightening Serum, which uses a total concentration of approximately 20% of vitamin C and vitamin C ester derivatives, and adds ferulic acid and vitamin E derivatives.

In addition, skin care brands such as Paula's Choice, Timeless, and Cosmetic Skin Solution have also developed similar products.

Synergistic Combinations of Ferulic Acid

Ferulic Acid and Multiple Acids: In 2007, researchers from L'Oréal published an article in the Journal of Cosmetic Dermatology titled "Application of Hydroxy Acids on the Skin: Properties of C8-Lipohydroxy Acid," which introduced L'Oréal's patented ingredient C8-lipoic acid (C8-LHA) and mentioned that adding a "stratum corneum separating agent" (such as lipohydroxy carbon compounds) to ferulic acid can enhance its efficacy. In L'Oréal's new Pure Light Essence, this combination is used. The product adopts a dual-tube design. The inner tube contains 7.6ml of 0.5% ferulic acid, and the outer tube contains 30ml of the whitening ingredient 377, and also adds niacinamide, as well as the combination of "capryloyl salicylic acid LHA + papain + caffeine".

Ferulic Acid and Resveratrol: Both ferulic acid and resveratrol are considered truly effective antioxidant ingredients, and both can be used for skin whitening. This combination is also a typical synergistic whitening combination and is used in many products that focus on antioxidant and whitening effects. The Ordinary once launched a high-concentration antioxidant essence, and the formula used 3% resveratrol + 3% ferulic acid.

Ferulic Acid and Retinol: The combination of ferulic acid and retinol can enhance the anti-aging effect, and ferulic acid can appropriately reduce the irritating effect of retinol, neutralize the free radicals generated by retinol, and reduce sun damage. The American skin care brand Dr. Dennis Gross launched the Retinol + Ferulic Acid series of products, which are composed of two types of retinol (trans-retinol and encapsulated retinol), bakuchiol, rambutan, and ferulic acid, and focus on anti-wrinkle and spot lightening.

In conclusion, in the application of cosmetics, ferulic acid can not only assist other antioxidants, but also fight against free radicals and photoaging on its own. Its wide application well reflects the scientific nature of cosmetic compounding.

Diversified Applications - Upgrades in Product Formulations and Packaging

In the L'Oréal Hydra Genius Aura Liquid Care Freeze-Dried Brightening Ampoule Set, ferulic acid is made into freeze-dried tablets. This completely anhydrous form is more conducive to maintaining the activity of the ingredients. The freeze-dried ferulic acid, together with the hyaluronic acid and vitamin C derivatives in the ampoule, plays a role in brightening the skin tone and combating wrinkles.

The Lancôme Advanced Génifique Soothing and Repairing Concentrate seals the ferulic acid solution separately in a blue dropper to maintain its activity. In this product, ferulic acid works in conjunction with bifida ferment lysate, caffeine, and centella asiatica extract, making it more suitable for sensitive skin.