Kojic acid: What you need to know Kojic acid is a chemical skin whitening material produced from different types of fungi. It is also a by-product of fermented soy sauce and rice wine. Kojic acid is sometimes used in the food industry as a natural preservative. One of the main uses of kojic acid, however, is in some health and cosmetic products. In this article, we look at how kojic acid is used, what possible health benefits it might have, and what the potential risks and side effects are. Uses Kojic acid is sometimes used in health and beauty products to lighten the skin. It may be used to treat skin conditions, such as sun damage, scars, and age spots. The science behind how kojic acid works as a lightening agent involves its effect on melanin production. Melanin is a naturally occurring pigment in the body that gives the eyes, hair, and skin their color. An amino acid called tyrosine is needed to support the production of melanin. Kojic acid works by blocking tyrosine from forming, which then prevents melanin production. Decreased melanin production may have a lightening effect on the skin. Kojic acid is most commonly used in cosmetic products, such as creams, lotions, and serums, and other moisturing raw materials. It is also used in some soaps. Many products with kojic acid are intended for use on the hands or face. Products containing kojic acid can also be used on other parts of the body, such as the legs and arms, functioning as skin whitening material. The concentration of kojic acid in cosmetics is often between 1 and 4 percentTrusted Source. Certain products containing kojic acid, such as serums, are meant to be applied to the skin and left on and absorbed. Some products, such as soaps, are applied and washed off. Benefits The benefits of using products containing kojic acid may include the following: Anti-aging raw material effect: Products containing kojic acid may lighten the skin, which can improve the appearance of age spots and sun damage. The reduction of dark spots can have an anti-aging effect. Treat melasma: Kojic acid may also be helpful in decreasing melasma, which is darkening of the skin due to pregnancy. Decrease the appearance of scars: Kojic acid may also reduce the discoloration of scars. Although the acid does not improve the thickness of scar tissue, it may reduce dark pigmentation associated with certain types of scars. Lightening the scar may make it less noticeable. Antifungal benefits: Kojic acid is also thought to have some antifungal benefits. It may be helpful in preventing and treating certain fungal infections, such as athlete's foot and yeast infections. Antibacterial effects: Kojic acid may also provide antibacterial benefits. It may help decrease the chances of developing common types of bacterial skin infections. Safety Before using products containing kojic acid, it is important to make sure they are safe. Cosmetic products are not regulated the same way medicines and foods are. Cosmetic products are not required by law to be approved by the United States Food and Drug Administration (FDA)Trusted Source before being sold. The FDA do have a voluntary registration program for cosmetic manufacturers in which companies can report how their products are made. Also, the Cosmetic Ingredient Review (CIR) Expert Panel reviews safety. A reviewTrusted Source of kojic acid found that some studies in mice suggested there was a link to tumor growth when the acid was used in high concentrations. However, this link was weak since kojic acid is slowly absorbed into the circulation. It is unlikely that levels would become high enough to cause cancer in humans. According to the reviewers, the available data suggest that the use of products containing kojic acid with a concentration of 2 percent for products left on the skin is considered safe. The CIR Expert Panel agreed that kojic acid could be safely used in cosmetic products. Raw kojic acid is available, but it is not recommended for skin use. Kojic acid should be diluted to concentrations of no more than 4 percent. A concentration of 1 to 2 percent is recommended to reduce the chance of skin irritation. Trying to add raw kojic acid to creams or lotions may be difficult and result in levels that are irritating to the skin. Using pre-made skin lotions and creams that already contain kojic acid in specific concentrations may be a better option. How can antioxidants benefit our health? Antioxidation raw materials are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. They are sometimes called "free-radical scavengers." The sources of antioxidants can be natural or artificial. Certain plant-based foods are thought to be rich in antioxidants. Plant-based antioxidants are a kind of phytonutrient, or plant-based nutrient. The body also producesTrusted Source some antioxidants, known as endogenous antioxidants. Antioxidants that come from outside the body are called exogenous. Free radicals are waste substances produced by cellsTrusted Source as the body processes food and reacts to the environment. If the body cannot process and remove free radicals efficiently, oxidative stress can result. This can harm cells and body function. Free radicals are also known as reactive oxygen species (ROS). Factors that increase the production of free radicals in the body can be internal, such as inflammation, or external, for example, pollution, UV exposure, and cigarette smoke. Oxidative stress has been linkedTrusted Source to heart disease, cancer, arthritis, stroke, respiratory diseases, immune deficiency, emphysema, Parkinson's disease, and other inflammatory or ischemic conditions. Antioxidants are said to help neutralize free radicals in our bodies, and this is thought to boost overall health. Benefits Antioxidants (anti-wrinkle raw materials)can protect against the cell damage that free radicals cause, known as oxidative stress. Activities and processes that can lead to oxidative stress includeTrusted Source: mitochondrial activity excessive exercise tissue trauma, due to inflammation and injury ischemia and reperfusion damage consumption of certain foods, especially refined and processed foods, trans fats, artificial sweeteners, and certain dyes and additives smoking environmental pollution radiation exposure to chemicals, such as pesticides and drugs, including chemotherapy industrial solvents ozone Such activities and exposures can result in cell damage. This, in turn, may lead to: an excessive release of free iron or copper ions an activation of phagocytes, a type of white blood cell with a role in fighting infection an increase in enzymes that generate free radicals a disruption of electron transport chains All these can result in oxidative stress. The damage caused by oxidative stress has been linked to cancer, atherosclerosis, and vision loss. It is thought that the free radicals cause changes in the cells that lead to these and possibly other conditions. An intake of antioxidants is believed to reduce these risks. According to one studyTrusted Source: "Antioxidants act as radical scavenger, hydrogen donor, electron donor, peroxide decomposer, singlet oxygen quencher, enzyme inhibitor, synergist, and metal-chelating agents." Other research has indicatedTrusted Source that antioxidant supplements may help reduce vision loss due to age-related macular degeneration in older people. Overall, however, there is a lack of evidenceTrusted Source that a higher intake of specific antioxidants can reduce the risk of disease. In most cases, results have tended to show no benefit, or a detrimental effect, or they have been conflicting. Types There are thought to be hundreds and possibly thousands of substances that can act as antioxidants. Each has its own role and can interact with others to help the body work effectively. "Antioxidant" is not really the name of a substance, but rather it describes what a range of substances can do. Examples of antioxidants that come from outside the body include: vitamin A vitamin C vitamin E beta-carotene lycopene lutein selenium manganese zeaxanthin Flavonoids, flavones, catechins, polyphenols, and phytoestrogens are all types of antioxidants and phytonutrients, and they are all found in plant-based foods. Each antioxidant serves a different function and is not interchangeable with another. This is why it is important to have a varied diet.