Beauty Glossary: A

This alphabetical guide is intended to give you a quick reference to cosmetic ingredients and other terms used throughout this site.

Accutane - an acne medication that inhibits oil production; side effects include hair loss, headaches, liver problems, extreme dryness of the skin and eyes, and birth defects.

Acetone - a solvent used in nail polish, nail polish removers, and astringents that can cause nausea, ear, nose, and throat irritation, and dermatitis.

Acetonitrile (methyl cyanide) - an extremely toxic chemical found in many artificial nail removers. Its use should be avoided, especially by pregnant women.

Acne - an inflammation caused by blockage of the oil glands, which results in blackheads and pimples.

Aesthetician - a trained professional who provides spa or salon treatments, such as facials and massages, that relax the body and clean or beautify the skin.

Age spots (also known as liver or brown spots) - concentrations of melanin trig gered by unprotected exposure to the sun over a long period of time.

Alcohol, SD (SD alcohol) - denatured ethyl alcohols found in hair and skin care products like astringents and toners. Because they can be drying to the hair and
skin, people with sensitive skin should avoid using them.

Algotherapy - therapeutic use of seaweed in spa treatments.

Allantoin - a skin-soothing, anti-inflammatory ingredient extracted from urea, comfrey, or chamomile that is used to soothe sunburned, irritated skin.

Allergen - a substance that produces an allergic reaction.

Almond oil - an easily absorbed, emollient oil extracted from the seeds of sweet almonds.

Aloe vera gel - derived from the leaves of the Aloe barbadensis plant, it moisturizes and soothes burns and skin irritations.

Alpha-hydroxy acids (AHAs) - acid extracts from natural or synthetic sources that chemically exfoliate the top layer of skin. There are five types: citric acid, tartaric acid, malic acid, lactic acid, and glycolic acid; also known as fruit acids.

Alum - an astringent used in antiperspirants to prevent irritation from aluminum chloride.

Aluminum salts - aluminum acids used in antiperspirants to stop perspiration and kill bacteria, thereby preventing body odor. Common examples include aluminum
hydroxide, aluminum stearate, and aluminum caprylate. Some researchers believe that aluminum salts contribute to Alzheimer's disease.

Amino acids - substances used by the body to build the proteins that form the base of skin, hair, and nails. Added to shampoos and conditioners, they effectively fill-in the cracks in the hair shaft.

Ammonium lauryl sulfate - a detergent used in shampoos and cleansers.

Ammonium thioglycolate - an active ingredient in hair relaxers (straighteners), it breaks the protein bonds that give hair its texture.

Analgesic - a substance that relieves pain.

Aniline - a colorless liquid obtained from coal tar, from which many hair colors and dyes are derived; about 1 in 100 women are allergic to it.

Animal extracts - fat or tissue extracted from cows, sheep, and pigs that is added to skin or hair care products with an intended rejuvenating effect.

Antifungal - counteracts fungal infections such as athlete's foot and nail fungus.

Anti-inflammatory - reduces swelling and inflammation.

Antioxidants - substances found in vitamins and other materials that help repair and prevent cell damage caused by free radicals. Examples include grapeseed extract, green algae (flavonoids), lycopene (beta-carotene), ginseng, licorice, rosemary, juniper, lipoic acid, alpha-linoleic acid. The strongest known natural antioxidants are ginkgo biloba and green tea.

Antiperspirant - a substance that inhibits perspiration.

Antiseptic - a substance that kills bacteria and inhibits their growth.

Arnica - extracts from the flowers of this plant are used to heal wounds and soothe irritated skin.

Aromatherapy - the therapeutic use of botanical oils that are distilled or cold-pressed from plants and flowers.

Ascorbic acid - Vitamin C, an antioxidant used as a preservative in cosmetics.

Ascorbyl palmitate - fat-soluble Vitamin C.

Astringent - a substance, such as witch hazel or alcohol, that causes skin tissue to tighten.

Avobenzone (.aka Parsol 1789.) - an ingredient in sunscreens that blocks UVA radiation.

Awapuhi - extracted from Hawaiian white ginger and used in shampoos and massage oils, it stimulates the circulation and relieves sore muscles.

Ayurveda - an ancient science of holistic medicine originating in India.

Azelaic acid - an oleic acid derivative used by dermatologists to treat acne.

Azulene - an anti-inflammatory extracted from chamomile and yarrow flowers, it soothes the skin.