Skin Care Cosmetics Ingredients Glossary

M

macadamia nut oil. Used in cosmetics as an emollient for dry skin.

madecassoside. One of four principal bioactive compounds in the plant extract Centella asiatica. One double-blind study has shown even small amounts of this compound (0.1% in one case) combined with vitamin C have benefit when applied to sun-damaged skin. It also plays a role in wound-healing, collagen synthesis, and functions as an antioxidant.

magnesium. Earth mineral that has strong absorbent properties and some disinfecting properties. Magnesium obtained via diet or oral supplements is essential for maintaining health.

magnesium aluminum silicate. Powdery, dry-feeling, white solid that is used as a thickening agent and powder in cosmetics.

magnesium ascorbyl palmitate. Stable derivative of vitamin C that can be an effective antioxidant. See vitamin C.

magnesium ascorbyl phosphate. Form of vitamin C that is considered stable and an effective antioxidant for skin. For skin lightening, there is only a single study showing it to be effective for inhibiting melanin production. The study concluded that a moisturizer with a 10% concentration of magnesium ascorbyl phosphate “suppressed melanin formation…. The lightening effect was significant in 19 of 34 patients with chloasma or senile freckles and in 3 of 25 patients with normal skin.” One study is not exactly anything to write home about, not to mention that at present there are no products on the market that contain 10% magnesium ascorbyl phosphate.

magnesium carbonate. Inorganic mineral salt used as an absorbent, opacifying agent, coloring agent, or to adjust the pH of cosmetic products.

magnesium gluconate. Magnesium is an essential mineral the body uses to maintain circulatory and nervous system function. There is a small amount of research showing that it has antibacterial properties. There is also research showing it may be helpful for healing burns.

magnesium hydroxide. Active ingredient in milk of magnesia. It is an absorbent and has antibacterial properties for skin.

magnesium laureth sulfate. Mild detergent cleansing agent. See surfactant.

magnesium oleth sulfate. Mild detergent cleansing agent. See surfactant.

magnesium stearate. Used as a thickening agent in cosmetics.

magnesium sulfate. Commonly known as Epsom salt, a magnesium salt used as a thickening agent.

malic acid. See AHA.

mallow. Can be used as a thickening agent in cosmetics and may have anti-inflammatory and soothing properties for skin due to its content of mucilage, flavonoids, and anthocyanidins (Source: Healthnotes Review of Complementary and Integrative Medicine, www.healthwell.com/healthnotes/Herb/Mallow.cfm).

Malva sylvestris extract. Extract from the blue mallow flower, it may have some anti-inflammatory and soothing properties for the skin, as well as some potential antioxidant benefits.

Malvaceae extract. Extract from plants of the Malvaceae family, which includes over 1,000 species, found in tropical and temperate regions the world over. Their varying benefits and problems are diverse. Consequently, if “Malvaceae” is present on a cosmetic ingredient label, it is misleading, because each of the 1,000 species has its own pros and cons.

mandarin orange oil or extract. Primarily used as a fragrance; it can be a skin irritant. There is no research showing it has any benefit when applied topically.

mandelic acid. Alpha hydroxy acid, also known as amygdalic acid. There is scant research showing this to be an effective alternative to other AHAs, though it does have germicidal activity. Unlike glycolic acid, mandelic acid is light-sensitive and should be packaged in an opaque container (Source: Handbook of Cosmetic and Personal Care Additives, Second Edition, volume 2, Synapse Information Resources, 2002).

manganese gluconate. Mineral found in trace amounts in tissues of the body. While manganese plays a vital role in the processes of many body systems, there is no evidence it serves any purpose topically on skin, though it may act as an antioxidant.

manganese violet. Coloring agent/additive permanently listed (as of 1976) by the FDA for use in cosmetic products, including those designed for use around the eye.

Mangifera indica root. Extract derived from the mango tree; it can have antioxidant properties (Source: Journal of Agricultural Food Chemistry, February 2002, pages 762–766).

manuka oil. Extract derived from the New Zealand tea tree; the oil is similar to that of the Australian tea tree, Melaleuca alternifolia. Manuka oil has antifungal and antibacterial properties. See tea tree oil.

marigold. See calendula extract.

marionberry. Fruit that has potent antioxidant properties (Source: Journal of Agricultural Food Chemistry, June 5, 2002, pages 3495–3500).

marjoram. Herb with a fragrant component used in cosmetics; can be a skin irritant.

marshmallow. See mallow.

Mastocarpus stellatus. See algae.

mate extract. See yerba mate extract.

Matricaria oil. See chamomile.

matrix metalloproteinases. Also called MMPs, a group of 23 different enzymes that cause substances in the body to break down. Of the 23 types, MMP-1, also known as collagenase, is responsible for the destruction of collagen. Generated primarily by unprotected sun exposure and the aging process, it is also present in sebum (which may be a cause of acne).

One of the primary ways to decrease MMPs in skin, particularly MMP-1 is smart sun behavior and use of well-formulated sunscreens. There is also research showing that epigallocatechin-3-gallate (a derivative of green tea), retinoic acid (RA), eicosapentaenoic acid (an omega-3 fatty acid), beta-carotene, DHEA (though this is controversial), polysaccharides, vitamin E, and vitamin C, and flavonoids, to name a few, can inhibit MMPs and increase TIMPs (tissue inhibitors of metalloproteinases; when TIMPs increase in skin, MMPs decrease).

MEA. Abbreviation for monoethanolamine. See alkyloamides and triethanolamine.

meadowsweet extract. Extract that can have anti-inflammatory properties.

Medicago sativa. See alfalfa extract.

Melaleuca alternifolia. See tea tree oil.

Melaleuca cajeputi oil. There is no research showing that this oil, which is derived from a plant in the same family as the plant that is the source of tea tree oil, has any antibacterial properties. It may cause skin irritation (Source: The Illustrated Encyclopedia of Essential Oils, Rockport, MA, Element Books, 1995, page 170).

Melia azadirachta. See neem extract or oil.

melibiose. Saccharide that can have good water-binding properties. See mucopolysaccharide and natural moisturizing factor (NMF).

Melissa officinalis. See balm mint extract and counter-irritant.

Mentha arvensis. See cornmint.

Mentha piperita. See counter-irritant and peppermint.

Mentha spicata. See counter-irritant and spearmint oil.

Mentha viridis. See counter-irritant and spearmint oil.

menthol. Derived from peppermint; menthol can have the same irritating effect as peppermint on skin. See counter-irritant and peppermint.

menthone. Major constituent of peppermint. See peppermint.

menthoxypropanediol. Synthetic derivative of menthol. It is known to produce effects that are twice as strong as menthol, which makes it doubly irritating for skin or lips. Menthoxypropanediol is most often used in lip-plumping products. See menthol. menthyl anthranilate. Also known as meradimate, this is a synthetic sunscreen active is a partially effective UVA sunscreen, but because it only protects up to 336 nanometers, it does not make the grade for providing sufficient UVA protection on its own. It is not used very often, but I could not find reliable confirmation as to why that is.

menthyl lactate. Used as a cooling agent and fragrance in cosmetics. It is a derivative of menthol and is supposed to be less irritating than menthol. See counter-irritant and menthol. meradmiate. See menthyl anthranilate.

methanol. See alcohol.

methionine. See amino acid and antioxidant.

methyl gluceth-20. Liquid that functions as a water-binding and skin-conditioning agent.

Methyl trimethicone. See silicone.

methylchloroisothiazolinone. In combination with methylisothiazolinone, it goes by the trade name Kathon CG. Introduced into cosmetics in the mid-1970s, it elicited a great number of sensitizations in consumers. This led to it not being included in cosmetics other than rinse-off products.

methyldibromo glutaronitrile. Formaldehyde-releasing preservative (Source: Contact Dermatitis, December 2000, pages 339–343). See formaldehyde-releasing preservative.

methyldihydrojasmonate. Synthetic fragrant component.

methyleugenol. Natural constituent of plant oils such as those from rose, basil, blackberry, cinnamon, and anise. According to the November 9, 1998, issue of The Rose Sheet (an insider cosmetics industry newsletter), the National Toxicology Program Board of Scientific Counselors concluded that “methyleugenol, a component of a number of essential oils, has shown clear evidence of carcinogenic activity in male and female rats and mice.” The study is an animal model and so the results may or may not be applicable to humans.

methylisothiazolinone. Preservative that should be used only in rinse-off products because it can be too irritating when left on skin. See methylchloroisothiazolinone and preservatives.

methylparaben. See parabens.

methylpropanediol. Glycol that functions as a solvent. Methylpropanediol can enhance the penetration of ingredients (such as salicylic acid) into the skin.

methylsilanol mannuronate. See silicone.

methylsilanol PEG-7 glyceryl cocoate. A glyceryl ester used as an emollient and thickening agent in cosmetics. See glyceryl ester and silicone.

methylsufonylsulfate. See antioxidant.

methylsulfonylmethane. Also known as MSM. There is no published research to back up claims made about any benefit this sulfur compound may have for arthritis or other physical ailments. There is no research about its effect when applied topically. Sulfur is stored in every cell of the body, particularly in the hair, nails, and connective tissue of joints and skin, where it is an important structural protein component. An MSM manufacturer sponsored two very small trials, but the results have not been published. Until additional research is published, MSM enthusiasm should be tempered. MSM is available in capsules and powder for oral intake or in creams for topical use. To date, there have been no reports of toxicity.

Mexoryl SX. Also called ecamsule (technical name terephthalylidine dicamphor sulfonic acid), Mexoryl SX is a synthetic sunscreen agent developed and patented by L’Oreal and used in the company’s sunscreen products sold outside the United States since 1993 (first approved for use in Europe in 1991). In July 2006, the FDA approved the use of Mexoryl SX in the United States, but only in a single sunscreen product, La Roche-Posay’s Anthelios SX SPF 15 (L’Oreal owns La Roche-Posay). The FDA did not approve Mexoryl SX for use in any other sunscreen; only in that one specific product.

mica. Earth mineral included in products to give them sparkle and shine.

microcrystalline wax. Plastic-type, highly refined wax derived from petroleum. Used as a thickener and to give products a semi-solid to solid smooth texture.

Microcystis aeruginosa. Latin name for spirulina. See algae.

milk protein. See protein.

milk vetch root. There is a good deal of research showing this root has antioxidant properties (Source: www.naturaldatabase.com), but there is little evidence that it functions that way when applied topically.

millet seed extract. Extract from a cereal grain that has no established benefit for skin, but is added to cosmetic formularies as a skin-conditioning agent.

mimosa oil or extract. Extract used as a fragrance in cosmetics.

mineral oil. Clear, odorless oil derived from petroleum that is widely used in cosmetics because it rarely causes allergic reactions and it cannot become a solid and clog pores. Despite mineral oil’s association with petroleum and the hype that it is bad for skin, keep in mind that petroleum is a natural ingredient derived from the earth and that once it becomes mineral oil USP (cosmetics- and pharmaceutical-grade mineral oil), it has no resemblance to the original petroleum. Cosmetics-grade mineral oil and petrolatum are considered the safest, most nonirritating moisturizing ingredients ever found. Yes, they can keep air off the skin to some extent, but that’s what a good antioxidant is supposed to do; they don’t suffocate skin! Moreover, mineral oil and petrolatum are known to be efficacious in wound healing, and are also among the most effective moisturizing ingredients available.

mint. Can be a skin irritant and cause contact dermatitis. See counter-irritant.

Mitracarpe scaber extract. Extract from a plant native to West Africa, it has been shown to have some antimicrobial properties.

mixed fruit extracts. See sugarcane extract.

montmorillonite. See bentonite.

Morus bombycis root extract. See mulberry extract.

Morus nigra root extract. See black mulberry.

mucopolysaccharide. Also known as glycosaminoglycans. This is a large class of ingredients that includes hyaluronic acid, which is found universally in skin tissue. These substances, in association with protein, bind water and other cellular elements so they remain intact, forming a matrix that holds skin cells together. See natural moisturizing factor (NMF) and intercellular matrix.

Mucor miehei extract. Extract of a type of mold whose enzymes are used as a food additive and flavor enhancer in cheeses. It has no established benefit for skin, though companies using this ingredient often describe its enzymatic action as being akin to exfoliation. If that is the case, there is no proof to support the claims.

mugwort extract. There is no research showing this extract has any benefit for skin (Sources: www.naturaldatabase.com; and www.pubmed.com).

mulberry extract. Due to its arbutin content, this extract can have some value in preventing melanin production. Although there is limited research showing this to be the case, the research has been done only in vitro. See arbutin.

myristic acid. Detergent cleansing agent that also creates foam and can be drying. See surfactant.

myristyl myristate. Used in cosmetics as a thickening agent and emollient.

myristyl nicotinate. A derivative of nicotinic acid, a component of vitamin B3 (niacin) that isn’t the same ingredient as niacinamide, yet functions in nearly the same manner. There is research concerning myristyl nicotinate’s ability to improve skin barrier function, mitigate signs of sun damage, and reduce the incidence of atopic dermatitis, commonly known as dry skin. What’s more, it is compatible with several prescription drugs used to treat various skin conditions and is believed to enhance their efficacy and/or minimize side effects. Myristyl nicotinate is stabilized to prevent the release of (or quick conversion to) nicotinic acid, which can cause facial flushing, particularly in those dealing with rosacea. The benefits attributed to myristyl nicotinate are the same as those for niacinamide, which makes sense given their close relation.

myrrh. Fragrant gum resin that can be a skin irritant. There is little research showing it has any benefit for skin (Source: Healthnotes Review of Complementary and Integrative Medicine, www.healthwell.com/healthnotes/), although there is a small amount of research showing it may have antifungal and antibacterial properties (Source: Planta Medica, May 2000, pages 356–358).

myrtle extract. Contains volatile oil and tannins, and can have fungicidal, disinfectant, and antibacterial properties. It contains 1,8-cineole, a constituent responsible for toxicity. It is recommended that this not come in contact with skin.

• Myrtus communis extract. See myrtle extract.-