Acid-alkali balancer refers to the pH scale for chemicals. All ingredients and compounds will fall on either the acid or the alkali side of the scale, or into a neutral range. A component that changes the pH of a compound by its addition is an acid-alkali balancer. One such type of component is a buffer, which is an alkali ingredient added to an acid to make it less irritating. See acid mantle.

The acid mantle of the skin on the face is a protective barrier against bacteria and other microorganisms formed by our own sebum and sweat. The pH of the acid mantle ranges between 4.5 and 6.2 on the pH scale. It is important to use skincare products that keep the pH of facial skin in this range or infection and inflammation can occur. For example, facial cleansers by nature are alkaline and require acidic ingredients to be added to them to adjust the pH of the overall product and maintain the acid mantle of the face.

An active constituent is the part of a plant that gives the plant its medicinal properties. In the case of an essential oil, the essential oil is extracted from the plant (or part of a plant) and within the essential oil there will be many chemical constituents (all of the chemicals that make up the oil). Some of these chemical constituents will have properties that are medicinal in human beings, or give protection to the plant, etc. These are the active constituents.

An alkaloid is a nitrogen-containing organic molecule that has a pharmacological effect on humans and animals; usually analgesic or anasthetic.

Allantoin is a botanical extract of the comfrey plant and is used for its healing, demulcent, and anti-irritatant properties. It is a biogenic skin softener that accelerates wound healing and helps to heal skin irritations, stimulates the growth of healthy tissue, and improves hydration in the skin. 

An alterative is a treatment or substance that restores health.

An analgesic is a medication that reduces or eliminates pain.

An anasthetic is an agent that causes loss of sensation.

Anthocyanin is a water soluble pigment that reflects the red to blue range of the visible spectrum. It is often observed in the plant kingdom, where it serves to color anything from fruits to the autumn leaves. The pigment acts as a powerful antioxidant helping to protect the plant from UV damage. Anthocyanins belong to a class of compounds called flavonoids.

Anthraquinones are a group of phytochemicals including: senna (purgative), barbaloin (from aloe vera which heals skin burns and ulcers), and hypericin (analgesic).

Anti-aging is not used here to mean a lifespan extension or a reversing of the clock. Products with this claim on the label refer only to slowing down the effects of photoaging. Photoaging is the process by which skin is changed or damaged as a result of exposure to ultraviolet radiation in sunlight and other sources. The long-term effects of this process on the skin are wrinkles, pigmentation problems, and susceptibility to cancer. Dermatologists estimate that 80-85% of skin aging is caused by UVA and UVB rays. UVA rays weaken the skin’s collagen and elastin fibers, causing wrinkling and sagging in the skin. This makes a UVA and UVB sunblock the most potent anti-aging product in existence. The idea that topical applications of antioxidants like vitamin E and polyphenols extend the youthful appearance of skin stems from the free radical theory of skin aging.

An antibacterial destroys or inhibits the growth of bacteria.

An antifungal destroys or inhibits the growth of fungi.

An anti-inflammatory prevents or reduces inflammation. Inflammation is defined as a localized protective reaction of tissue to irritation, injury, or infection, characterized by pain, redness, swelling, and sometimes loss of function.

An anti-irritant prevents or reduces irritation. Irritation is a condition of inflammation, soreness, or irritability of a bodily organ or part. A likely symptom of irritation in the skin is itchiness.

An antimicrobial is a substance that kills or slows the growth of microbes like bacteria, fungi, viruses or parasites. By nature, antimicrobials have preserving properties in skincare products.

Antioxidants are vitamins, amino acids, and other natural substances that prevent oxidation. In biological systems, the normal processes of oxidation produce free-radicals. Free-radicals are aggressive, unstable, oxygen containing molecules that have lost an electron and need to steal one from another molecule to regain stability. This creates a chain reaction damaging to each cell involved. Free radicals damage cell membranes and normal cellular metabolism. They can also damage DNA and RNA, contribute to the hardening of collagen and elastin cells, and cause cancer. This cell damage leads to premature aging, increased skin sensitivity, irritation, age spots, and dryness. The main focus of anti-aging skincare products is on antioxidants that combat free-radicals in the skin. Applied topically, they neutralize free radicals before they attach themselves to the cell membrane and damage the cell. According to scientific researchers, the most effective agents are good old vitamins E, C and A. “At the top of the list of wonder chemicals used in anti-ageing products are the ubiquitous antioxidants, one of the few morsels of scientific terminology that has made it into the public consciousness unscathed. If consumers are looking for a significant and permanent effect on the skin, it is the antioxidants in which they should put their faith.” EMBO reports vol. 3/no. 8/2002 (European Molecular Biology Organization), Andrew Moore. Antioxidants are used both to help the condition of the skin and to help products retain their properties, thus they are considered both functional and performance ingredients.

An antipsoriatic is a treatment or substance that positively affects psoriasis or its symptoms.

An antiseptic is a substance that prevents the growth and reproduction of various microorganisms (such as bacteria, fungi, protozoa, and viruses) on the external surfaces of the body. Some are true germicides, capable of destroying the bacteria, whilst others merely prevent or inhibit their growth. The objective of antiseptics is to reduce the possibility of sepsis, infection, or putrefaction by germs. Antibacterials have the same objective but only act against bacteria. Antibiotics perform a similar function, preventing the growth or reproduction of bacteria within the body. Disinfectants operate on nonliving objects such as medical instruments.

An antiviral destroys or inhibits the growth and reproduction of viruses.

Arbutin is a hydroquinone derivative found in certain plants that has antimicrobial properties. It is also used as a skin lightener because of its hydroquinone content and can have melanin-inhibiting properties.

Arabingalactan is an immune stimulating, anti-aging polysaccharide with gentle stimulating properties. 

An astringent is a substance or preparation that draws together or constricts body tissues and is effective in stopping the flow of blood or other secretions (such as sebum), usually locally after topical medicinal application. The word “astringent” is the present participle of the Latin word astringere, meaning “to bind fast”.

Azulene is a dark blue crystalline solid obtained by steam distillation of chamomile. It is used primarily as a coloring agent in cosmetics and has antioxidant and anti-inflammatory properties.

A bactericide is an agent that destroys bacteria.

Beta-carotene is one of three isomeric forms of carotene. Carotene is a tetraterpene, an orange photosynthetic pigment, important for photosynthesis and responsible for the orange color of the carrot. It does not actively contribute in photosynthesis, but instead transmits the energy it absorbs to chlorophyll. In use for humans, beta-carotene is a lipid-soluble antioxidant, so a small amount of fat is needed for absorption. It is a precursor of vitamin A and is converted to such in the liver.

β-glucan (or beta-glucan) is a polysaccharide that enhances skin immunity and wound closing, protects against UV damage, hydrates skin, is antioxidant, and is a strong anti-inflammatory.

A substance that is biogenic is naturally found in the body. Hence, biogenic substances are most effective and easily absorbed.

Carotnoids are a class of terpenoids that are highly antioxidant and brightly colored. These are the compounds that give color to carrots, corn, tomatoes, salmon, goldfish, and autumn leaves. They are: lycopene (reduce damage to DNA and proteins, UV protection), beta-carotene (boosts activity of immune cells, stimulates DNA repair, UV protection), alpha-carotene (anti-carcinogenic), lutein (absorbs damaging blue light), zeaxanthin (protects the eye), astaxanthin (10x more powerful antioxidant than any other carotenoid).

A cell membrane is the selectively permeable outer wall of every animal cell. It is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. It separates a cell’s interior from its surroundings and controls what moves in and out. Certain membrane proteins are responsible for the regulation of behavior and organization of cells in tissues.

Cell metabolism is the process (or really the sum of many ongoing individual processes) by which living cells process nutrient molecules and maintain a living state (carry out their various activities).

Cellulitis is an inflammation of the connective tissue underlying the skin that can be caused by bacterial infection. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken. It is unrelated to “cellulite,” a cosmetic condition featuring dimpling of the skin.

A cicatrizant is a medicine or application that promotes the healing of a sore or wound, or the formation of a cicatrix (scar).

Collagen is the main protein of connective tissue and the most abundant protein in mammals. The recticular layer of the skin is the deeper dermal layer (papillary being the other) connecting the skin to the body and containing protein fibers that give the skin its strength and elasticity. Collagen, produced by fibroblasts, makes up 70% of the dermis and gives the skin structure. In contrast, the quantity of elastin in the dermis is only about one-fifteenth of the collagen amount and gives the skin its flexibility. Damage to these fibers as they break down are the primary cause of the wrinkles and sagging that accompany aging. Unfortunately, elastin and collagen are not replaced naturally by the body alone, and the skin does not regain its once-pliable shape after being stretched and expanded over time. However, new research shows that certain ingredients such as vitamin A may stimulate collagen and elastin growth, which has the potential to slow down the aging process. There is a better chance of stimulating the growth of collagen than elastin in the skin. UV exposure is a main cause in the deterioration of collagen and elastin, so sunblock is crucial in retaining healthy collagen and elastin.

A comedogenic substance is one that clogs pores, possibly helping to cause or aggravating acne. More specifically, comedogenicity is the tendency of any topical substance to cause or to worsen a buildup of dead cells in follicles (referred to as pores), leading to the development of a comedo (blackhead).

Cortisol is a corticosteroid hormone that is involved in the body’s response to stress. It is released in the body in reaction to allergies, irritations, and inflammations in the skin, among others.

Coumarins are a group of active constituents in plants that have derivatives such as umbelliferone (absorbs UV rays) and psoralene (absorbs UV rays and used in treatments for psoriasis and eczema).

Couperose skin is characterized by redness and distended or broken capillaries from weakening of the capillary walls. It may have internal or external causes and be worsened by inflammation and extreme external conditions (like heat or cold). Couperose skin must be treated with care, as it is one of the more reactive and delicate skin conditions.

A demulcent is a substance, usually mucilaginous or oily such as marshmallow or glycerin, used to soothe or soften and protect, sometimes coating, irritated or inflamed tissues of the body. 

A decongestant is a substance or treatment that breaks up congestion. “Congestion” is generally used in reference to the sinuses but can also refer to a condition of the skin characterized by the presence of acne, comedones, or an overabundance of dead skin cells, and sometimes accompanied by inflammation.

Edema is a swelling of any organ or tissue due to accumulation of excess fluid and can be caused by a response to injury or infection.

Emollients are common cosmetic ingredients that are almost always fatty agents and can act as functional or performance ingredients. As a functional ingredient, emollients are vehicles that help spread, place, and keep other agents on the skin. As performance ingredients, they lubricate the skin’s surface and support the skin’s barrier function; emollients lie on top of the skin and prevent dehydration by trapping water, which increases the moisture content of the stratum corneum (outermost layer of the epidermis). This technique of moisturization is called occlusion and has a softening and soothing effect on the skin as well as filling in fine lines. See natural moisturizing factors.

Emulsifiers are a category of surfactant. This means that some cleansers (surfactants) can also act as emulsifiers. Emulsifiers keep oils and water blended in an emulsion (in products like lotions). Without emulsifiers, oil and water would separate into layers. Emulsifiers surround oil particles, allowing them to remain evenly distributed throughout the water. They can also act as thickening agents giving cosmetics their distinctive feel and form.

An erythema is an abnormal redness of the skin caused by capillary congestion. It is one of the cardinal signs of inflammation. For the most part any noticeable redness of the skin can be described as erythema and can be brought on by many things including: massage, exercise, rashes, extreme temperature, dry skin, etc.

Essential fatty acids are fatty acids that are required in the human diet. This means they cannot be synthesized by the body from other fatty acids and must be obtained from food. The essential fatty acids are omega-3 fatty acids and omega-6 fatty acids. Omega-3 fatty acids include: linolenic acid, EPA, and DHA. Omega-6 fatty acids include: linoleic acid, and arachidonic acid. Omega-9 fatty acids are not essential, because they can be synthesized from omega-3 and omega-6 fatty acids. Some of the food sources of omega-3 and omega-6 fatty acids are fish and shellfish, flaxseed (linseed), soybean oil, safflower oil, hemp oil, pumpkin seeds, leafy vegetables, and walnuts. Essential fatty acids play a part in many metabolic processes related to the health of the skin; they are required for the normal structure of all cell membranes and essential for healthy skin. Absorption of EFAs throught the skin is an effective method of acquiring EFAs for some skincare purposes, but including them in a diet is also required.

An exfoliant is an ingredient that assists in the process of exfoliation. Exfoliation is the removal of dead corneum cells (found in the outermost layer of the skin). There are two types of exfoliation, mechanical and chemical. Mechanical exfoliants literally knock dead cells off the surface of the skin, whereas chemical exfoliants loosen the bonds between cells in the stratum corneum (the outermost layer of the skin). The result of this process is to smooth the skin’s surface and improve its appearance thereby making it healthier and younger looking. It also encourages new cell growth. Oil-rich and blemish prone skin require more exfoliation than other skin types because pores become more clogged with oil and dead skin cell build-up. Regular exfoliation enables other skincare products to perform more effectively.

Fatty acids are substances typically found in plant and animal lipids (fats) and include compounds such as glycerides, sterols, and phospholipids. Fatty acids are used in cosmetics as emollients, thickening agents and surfactants. They are also part of the skin’s natural lipid barrier (see NMF) and help protect against oxidative damage to the skin.

Flavonoids are a large group of low molecular weight polyphenolic phytochemicals found in all vascular plants. They have been referred to as “nature’s biological response modifiers” because of their ability to modify the body’s reaction to other compounds such as allergens, viruses, and carcinogens. Flavonoids are important in skincare for their anti-allergenic, anti-inflammatory, and antibacterial properties. They are also powerful antioxidants. Some flavonoids exhibit the following properties: increasing intracellular vitamin C levels, decreasing capillary permeability and fragility, scavenging oxidants and free radicals, and inhibiting the destruction of collagen, while others have a water-binding ability. Some glycosides are flavonoids. Flavonoids (considered neutraceuticals) include: anthocyanins, catechins (increases metabolic rate), isoflavones (fungicides, can reduce menopausal symptoms), hesperitin (regenerates vitamin C), naringin (protects against radiation-induced DNA damage), rutin (strengthens capillary walls), quercetin (inhibits the manufacture and release of histamine and other allergic/inflammatory mediators), silymarin (strong anti-inflammatory), tangeretin (from tangerines, stops cancer cell proliferation), tannins (help build and strengthen collagen) etc.

A functional ingredient is one that performs a function within the product itself; they are ingredients that give the product spreadability, it’s texture and form, preserve it, and help the product penetrate into the skin. These ingredients can also be performance ingredients.

Gamma-linolenic acid (GLA) is an omega-6 fatty acid that exists primarily in plant fats. It is also known as GLA and is used in cosmetics as an emollient, antioxidant, and cell regulator. GLA is considered to promote healthy skin growth and is an anti-inflammatory agent. GLA is found in black currant oil or seeds, evening primrose oil, and borage oil. Of all the sources of GLA, evening primrose oil appears to be the most biologically active. As to health benefits, GLA is sometimes prescribed in the belief that it is an anti-inflammatory herb lacking the common side effects of other anti-inflammatory drugs. GLA is taken for autoimmune disorders, arthritis, eczema and PMS. Studies are currently being done using GLA as a cancer inhibiting agent and is said to be effective against breast cancer.

Gingerols, which are terpenes, are the main active constituents in ginger. These have analgesic, sedative, antipyretic (fever reducing), and antibacterial effects.

Hydrators, also known as humectants, hydrophilic agents, or water-binding agents, are substances that attract water to the skin’s surface. They can lock water on the skin, thus improving the symptoms of dehydration. Hydrators soften the surface of the skin, diminishing the lines caused by dryness. Many hydrators are included in natural moisturizing factors.

Linoleic acid is a polyunsaturated fatty acid (essential Omega-6) used in the biosynthesis of cell membranes. Linoleic acid is used as an emollient and thickening agent in cosmetics. It is an antioxidant and anti-inflammatory and may also be effective in cell regulation and skin-barrier repair.

Lipids are any of a group of organic compounds, including the fats, oils, waxes, sterols, and triglycerides, fatty acids, fatty-acid derived phospholipids, sphingolipids, glycolipids and terpenoids, such as retinoids and steroids, that are insoluble in water but soluble in common organic solvents, are oily to the touch, and together with carbohydrates and proteins constitute the principal structural material of living cells. Human sebum is also a lipid. Lipids are used in skincare products as emollients and thickening agents.

A lubricant is a substance that coats the skin and reduces friction. Silicone is a lubricant.

A lymphatic stimulant is a substance that stimulates the lymphatic system or its parts. In topical use this would indicate stimulation of the lymph vessels in the skin specifically. The lymph vascular system acts as an aid to the blood system. Lymph is circulated through the lymphatic vessels and filtered by the lymph nodes, which are gland-like bodies in the lymphatic vessels. The primary functions of the lymph vascular system are: to carry nourishment from the blood to the body cells, to act as a defense against invading bacteria and toxins, to remove waste material from the body cells to the blood, and to provide a suitable fluid environment for the cells. This process is of the utmost importance for healthy skin and for health in general.

Melanin is a complex protein made from pigment granules called melanosomes produced in the basal layer of the epidermis of human skin. It is the skin’s most formidible natural protection against UV radiation.

A menstrum is a carrier agent for a compound that will increase the penetrability (absorbability) or the speed of penetrability (absorbability) of that compound.

Mitosis is the process by which a cell divides into two identical daughter cells. This form of reproduction provides new cells to replace worn or injured ones.

Moisturizers are products formulated to add moisture to the skin. Most moisturizing products are basically combinations of emollients and hydrators. Thousands of possible combinations exist. Most often they are oil-in-water emulsions.

A mucilaginous substance secretes mucilage. Mucilage is a thick gluey substance, often produced by plants, and used for its demulcent properties. Marshmallow root is high in mucilaginous compounds, which have a soothing, healing quality on the skin.

Natural Moisturizing Factors

In the epidermis (the outermost 5 layers of the skin), cells are surrounded by lipids. These lipids serve as an intercellular cement, thereby holding the cells together. This intercellular cement helps prevent individual cells from water loss and provides hydration, thus creating the smooth, non-flaky appearance of healthy skin. The lipids that do this are often called natural moisturizing factors (NMFs). NMFs make up an expansive group of compounds that include amino acids, ceramides, hyaluronic acid, cholesterol, fatty acids, triglycerides, phospholipids, glycosphingolipids, urea, linoleic acid, glycosaminoglycans, glycerin, mucopolysaccharide, and sodium PCA (pyrrolidone carboxylic acid). Ingredients that mimic the lipid content of the skin are apricot oil, canola oil, coconut oil, corn oil, jojoba oil, lanolin, lecithin, olive oil, safflower oil, sesame oil, shea butter, soybean oil, squalene, and sweet almond oil. When any of these ingredients are used in skin-care products, they appear to help stabilize and maintain the epidermis. This support helps prevent surface irritation from penetrating deeper into the skin, works to keep bacteria out, and aids the skin’s immune/healing system. 

A nervine has the quality of acting upon or affecting the nerves; quieting nervous excitement.

Nutritive means nutritious or nourishing. A nutrient is any element or compound necessary for contributing to an organism’s metabolism, growth, or other functioning.

Oleic acid is a monounsaturated fatty acid found in various animal and vegetable sources. It is used as a surfactant and thickening agent. It is also called oeanic and oleanolic acid.

A parasiticide is an agent or preparation used to detroy parasites.

A performance ingredient is one that performs a function for the user of the product; these are what cause change in the appearance of the skin and actually do the work of the product. Performance ingredients can also be functional ingredients.

A pH balancer is any ingredient used to neutralize the pH of a chemical compound. In relation to the skin, a pH balancer would be any ingredient that would change the pH of the product into the acid mantle range.

Phenolic acids are a type of phytochemical that has great benefits for humans and skin. This groups includes vanillin (anti-inflammatory, DNA protecting), cinnamic acid, and hydroxycinnamic acids (a superset that includes p-coumaric, caffeic (regenerates oxidized vitamin E) and ferulic acid). Cinnamic acid and its derivatives (such as octyl methoxycinnamate a common sunscreen ingredient, and cinnamic esters that have healing properties) have many properties that are beneficial to skin. They are antibacterial, antifungal, and antiparasitic as well as UV absorbing. In fact, all phenolic acids have some plant sun protection in the form of UV radiation absorption. Hydroxycinnamic acids are all phenolcarboxylic acids, which include salicylic acid and are all fungicides.

Phospholipids are any of various phosphorous-containing lipids that are composed mainly of fatty acids, a phosphate group, and a simple organic molecule. Also called phosphatide. Phospholipids are essential to the function of cell membranes by providing a stable surrounding structure. Phospholipids are also a biogenic skin softeners, hydrators, anti-irritants, antioxidants, and improve transdermal penetration.

Photoaging is the process by which skin is changed or damaged as a result of exposure to ultraviolet radiation in sunlight and other sources and the long-term effects of this process on the skin such as wrinkles, age-spots, sagging, hyper- and hypo-pigmentation, and susceptibility to cancer. Effective preventative treatments for these effects include use of sunscreen and antioxidants.

Phytochemicals are compounds found in plants that are not required for normal functioning of the body but that nonetheless have a beneficial effect on health or an active role in the amelioration of disease.

Phytosterols are a group of phytochemicals that stimulate the formation and growth of new cells yet slow cancer cell growth.

A polyacetylene is a polymerized acetylene that has antimicrobial properties.

Polyphenols are a group of vegetable chemical substances, characterized by the presence of more than one phenol group. Flavonoids and tannins are types of polyphenols. Polyphenols have been shown to be strong antioxidants. For example, green tea polyphenols are potent antioxidant compounds that have demonstrated greater antioxidant protection than vitamins C and E.

Polysaccharides are polymers made up of many monosaccharides joined together by glycosidic linkages. They are complex carbohydrates such as starch and cellulose, to name a few, and are also found as a component of the skin in natural moisturizing factors. These skin polysaccharides are good water-binding agents and have antioxidant properties.

A preservative is a natural or synthetic chemical that is added to products to retard spoilage, whether from microbial growth, or undesirable chemical changes, such as oxidation. Antioxidants are all preservatives by nature, since they keep the ingredients from oxidizing. Any ingredient that has antibacterial, antifungal or antimicrobial properties also act as preservatives.

Regenerators, cell and tissue are substances that enable or speed regeneration, the ability to recreate lost or damaged cells or tissues.

A rejuvenator is a substance that works to restore to an original or new condition. Or it is a substance that restores youthful vigor or appearance; makes young again.

Salicylic acid is classified for skin as a beta-hydroxy acid. Salicylic acid is multifunctional in that it breaks up oil, is powerfully antiseptic, it is in fact an antimicrobial, exfoliates dead skin and debris, is stimulating, improves collagen production, and is particularly gentle and non-irritating for a member of its group, actually it is an anti-inflammatory. This makes it a perfect ingredient for blemished skin, and yet gentle enough even for delicate skin. Some natural sources include birch, willow bark, and wintergreen. Salicylates, the chemical group that salicylic acid belongs to, are used as sunscreen ingredients.

A sedative tends to calm, moderate, or tranquilize nervousness or excitement.

Saponins are triterpenes found in plants, especially in the plant skins where they form a waxy protective coating. They dissolve in water to form a soapy froth, have anti-inflammatory and antioxidant properties, and beneficially affect collagen.

Saponification is the process whereby oils and fats are combined with an alkaline substance to form a surfactant cleanser (soap). 

Seborrhea is a skin condition consisting in overactivity of the sebaceous glands characterized by excessive secretion of sebum or an alteration in its quality, resulting in an oily coating, crusts, or scales on the skin. Oil-rich skin does not necessarily, but can, suffer from seborrhea, which is a dermatological disorder. An anti-seborrheic substance counteracts the condition of seborrhea.

Sebum is the natural oil secreted in humans by the sebaceous glands that protects the surface of the skin (from environmental stressors) and lubricates both the skin and hair keeping them soft.

A sequestering agent is a substance that removes another agent or sets it apart, segregates, or isolates it.

A skin condition is different than a skin type. “Skin condition” generally refers to a temporary irregular condition of the skin that requires some treatment to bring the skin back to its normal state, or to disorders and diseases of the skin.  A skin type, on the other hand, refers to the general condition of a person’s skin. Skin types are genetically determined according to how much sebum a person produces. The skin types are: dry, normal, combination, and oily. Recently, there have been so many people with sensitivities that they now warrant their own type. Acneic skin (prone to acne) is considered a skin disorder. 

Silicones are a group of substances derived from the mineral silica (which in turn is derived from the element silicon). They are used in cosmetics as lightweight emollients. They are excellent protectants, helping to keep moisture trapped in the skin (occlusive) yet allowing oxygen in and out of the follicles. Silicones also add an elegant, silky, nongreasy feel to products because of their unique fluid properties, which give them a great deal of slip (they glide over the skin). They are also used as functional ingredients acting as vehicles for other ingredients, such as in makeup foundations. In addition, silicone is used extensively for wound healing and improving the appearance of scars.

A solvent is a substance (usually a liquid) that dissolves another substance to form a solution. Water is a universal solvent; it is capable of dissolving more substances than any other solvent. All cosmetics are either solutions, suspensions, or emulsions. Another use for solvents is to degrease skin and remove sebum.

Squalene (sometimes spelled squalane) is a biogenic organic triterpene. It is primarily found in shark livers, olives (this source rich in vitamins A, D, and E), and rice bran, as well as a lipid found in human sebum. Squalene is an emollient that is extremely penetrating and skin softening and has antioxidant, desensitizing, nourishing, and immune-stimulating properties. See NMF.

A stabilizer is a chemical which tends to inhibit the reaction between two or more other chemicals. It can be thought of as the antonym of a catalyst.

A styptic contracts the tissues or blood vessels; it is astringent. It also tends to check bleeding by contracting the tissues or blood vessels; it is hemostatic.

A surfactant is an agent that lowers the surface tension of a liquid. This term is an acronym for “surface active agent”. Surfactants can act as bridges that allow oil and water to mix or emulsify. During the emulsion process the molecules of surfactants have heads that bind with water and tails that bind with oil. Surfactants can also act as cleansers. They help reduce the surface tension of the dirt and oils on the skin’s surface, helping to lift them off the skin to be rinsed away. They are also the agents that cause cleansers to foam. Additionally, some surfactants are used to create “slip” in a product; helping other ingredients spread across the skin, placing them on the skin, and helping them penetrate the skin. These slip agents also have humectant properties.

Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins. They also, along with vitamin C, help build and strenthen collagen.

Terpenes are a class of hydrocarbons, produced by many plants, particularly conifers. They are major components of resin. Most essential oils consist of terpenes. They produce relaxing qualities.

A tonic is a substance that restores or increases body tone, or health.

A triglyceride is a biogenic naturally occurring ester of three fatty acids and glycerol that is the main constituent of fats and oils (lipids). In cosmetics they are used as an emollient and thickening agent.

UV or ultraviolet radiation is electromagnetic radiation of a wavelength shorter than that of the visible region. This “light” comes from numerous sources such as the sun and florescent bulbs. The two varieties most concerning to humans are UVA and UVB. Most sunscreen ingredients only screen UVB rays, while only the ingredients that provide a physical block (reflect the rays instead of absorbing them) will protect against both UVA and UVB rays. A sunscreen that contains in the latter category is advised for daily use (and frequent if in direct sunlight for long exposure) to protect against photo-aging in the skin and its effects.

Vitamin A is the skin’s most important fat-soluble nutrient.

Retinol, the dietary form of vitamin A, is an antioxidant vitamin important in vision and bone growth. It belongs to the family of chemical compounds known as retinoids. Vitamin A is referred to as a skin cell normalizer. This means that vitamin A can stimulate cell growth for healing and anti-aging effects OR slow down cell growth to improve skin conditions like acne or psoriasis. In cosmetics, vitamin A derivatives are used primarily as antiaging chemicals -- that is, they help to reverse the effects of photoaging giving a more youthful appearance. Vitamin A is absorbed through the skin and can increase the rate of cell turnover, aid in the functioning and repair of skin cells, and can provide a temporary increase in collagen thus improving skin elasticity and thickness both epidermal and dermal. Vitamin A is good for the following skin conditions: blemishes, wrinkles, eczema, dermatitis, skin allergies, insect bites and sunburns.

A vulnerary is used in the healing or treatment of wounds.