Beauty and Cosmetic Glossary - P

(TIP: LIP INK PRODUCTS ARE ALL NATURAL)

P. elisabethae. The "P." is short for Pseudopterogorgia. See sea whip extract.

PABA. See para-aminobenzoic acid.

padimate O. Sunscreen agent that protects skin primarily from the sun's UVB rays (Sources: www.photodermatology.com/sunprotection.htm; and Skin Therapy Letter, 1997, volume 2, number 5, www.dermatology.org/skintherapy).

Padina pavonica extract. See algae.

Paeonia suffruticosa extract. See peony root extract.

palm glyceride. Used as an emollient and thickening agent in cosmetics. See glyceryl ester, and palm oil.

palm oil. Has emollient and antioxidant properties for skin (Source: Free Radical Biology and Medicine, 1997, volume 22, number 5, pages 761–769). See antioxidant, and natural moisturizing factors.

Palmaria palmata extract. Extract from a sea plant whose common name is dulse. See algae.

palmarosa oil. See geranium.

palmitates. Generally these are forms of fatty acids used in cosmetics as thickening agents and emollients. As is true for any emollient, they can potentially clog pores, depending on the amount used in the product. See fatty acid.

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

palmitoyl pentapeptide 3. Trade name Matrixyl. It is a fatty acid mixed with amino acids. The only research showing this to have significance for skin was carried out by the ingredient manufacturer, Sederma. In their research, three different "half-face" studies with a total of about 45 participants showed it to be better than a retinol or vitamin C product (Source: Journal of Cosmetic Science, January-February 2001, pages 77–78). Without independent substantiation, however, there is no way to know how accurate this company-funded research is. Further, according to Sederma's research, the recommended concentration for this ingredient is 3% to 5% and there are few, if any, products using more then just a trace amount in their products. See amino acid, and fatty acid.

Panax schinseng. See ginseng.

pansy extract. There is a small amount of research showing it to have anti-inflammatory and antioxidant properties (Source: Natural Medicines Comprehensive Database, www.naturaldatabase.com).

pantethine. Also known as pantothenic acid. See pantothenic acid.

panthenol. Alcohol form of vitamin B. See pantothenic acid.

pantothenic acid. Also called vitamin B5, and often touted as being effective for acne. However, there is only one study supporting this notion and it dates from the early 1980s (Source: International Journal of Dermatology, 1981, volume 20, pages 278–285). There is no current research showing this to be an effective treatment for acne, but there is a small amount of research showing that it can be effective for hydration and wound healing (Source: American Journal of Clinical Dermatology, 2002, volume 3, number 6, pages 427–433).

papain. An enzyme extracted from papaya. Applied topically, papain can cause severe irritation, itching, and allergic reactions (Source: Natural Medicines Comprehensive Database, www.naturaldatabase.com). There is one study showing it to be effective for exfoliation, but only in pure concentration (Source: Archives of Dermatological Research, November 2001, pages 500–507). See enzymes.

papaya extract. Source of papain that theoretically can have exfoliating properties on skin, though almost none of the research has been performed on skin. Papaya can be a skin irritant. See enzymes.

para-aminobenzoic acid (PABA). Sunscreen ingredient rarely used since the 1990s because of strong potential for allergic reactions.

parabens. Group of preservatives, including butylparaben, propylparaben, methylparaben, and ethylparaben. They are the most widely used group of preservatives found in cosmetics. It is estimated that more than 90% of all cosmetic products contain some form of paraben. They are considered to cause less irritation than some preservatives. There is research showing that in animal models (and in vitro) parabens can have weak estrogenic activity. Whether that poses any health risk for humans using cosmetics is unknown. The very technical findings of the study, which involved both oral administration and injection into rat skin, did show evidence of a weak estrogen effect on cells in a way that could be problematic for binding to receptor sites that may cause proliferation of MCF-7 breast cancer cells. The study concluded that “future work will need to address the extent to which parabens can accumulate in hormonally sensitive tissues and also the extent to which their weak oestrogenic activity can add to the more general environmental oestrogen problem.” (Source: Journal of Steroid Biochemistry and Molecular Biology, January 2002, pages 49–60).

Does this mean you should stop buying products that contain parabens? That’s a good question, but the answer isn’t simple or conclusive, even by the standards of the study itself. This is a potentially serious issue and the FDA is conducting its own research to determine what this means for human health (Source: The Endocrine Disruptor Knowledge Base (EDKB), http://edkb.fda.gov/index.html). To keep the concern in perspective, it is important to realize that parabens are hardly the only substances that may have estrogenic effects on the body.

Any estrogen, including the estrogen our bodies produce, may bind to receptor sites on cells either strongly or weakly. Either this can stimulate the receptor to imitate the effect of our own estrogen in a positive way, or it can generate an abnormal estrogen response. Ironically, plant estrogens, or phytoestrogens (such as those found in soy), also produce chemicals that mimic estrogen. It is possible that a weak plant estrogen can help the body, but it can also be possible for a strong plant estrogen to make matters worse. For example, there is research that shows coffee to be a problem for fibrocystic breast disease. The reason for this is thought to be because coffee exerts estrogenic effects on breast cells (sources: American Journal of Epidemiology, October 1996, pages 642–644; Journal of the American Medical Women’s Association, Spring 2002, pages 85–90; 

A study in the Journal of Applied Toxicology, Volume 24, Issue 1, January-February 2004, pages 5-13 mentioned that “although recent reports of the oestrogenic properties of parabens have challenged current concepts of their toxicity in these consumer products, the question remains as to whether any of the parabens can accumulate intact in the body from the long-term, low-dose levels to which humans are exposed.” The study discussed the fact that traces of parabens have indeed been found in human breast tumors, but was quick to point out that it is unknown if this would be the same in healthy breast tissue. Parabens present in tumors may not be the causative factor but rather a result of parabens when cancer cells are present. See preservatives.

Paraffinum liquidum. See mineral oil.

Parietaria officinalis extract. Extract from a plant also known as pellitory. It can have antibacterial properties for skin but also has strong allergic and irritant potential when applied topically (Source: European Journal of Clinical Chemistry and Clinical Biochemistry, July 1996, pages 579–584; and Natural Medicines Comprehensive Database, www.naturaldatabase.com).

parsley extract. Can have antioxidant properties (Sources: Phytotherapy Research, August 2000, pages 362–365; and British Journal of Nutrition, June 1999, pages 425–426), but whether it has that effect when applied topically on skin is not known.

Parsol 1789. See avobenzone.

Passiflora edulis extract. See passion fruit extract.

passion fruit extract. There is no research showing this to have benefit for skin.

patchouli. Fragrant oil derived from mint. It contains eugenol and can be a skin sensitizer and irritant. See counter-irritant.

Paullinia cupana. See guarana.

pawpaw extract. See papaya.

peanut oil. Emollient plant oil similar to all nonfragrant plant oils.

pecan oil. Emollient plant oil similar to all nonfragrant plant oils.

pectin. Natural substance found in plants, especially apples, and used in cosmetics as an emulsifier and thickening agent.

PEG compound. PEG stands for polyethylene glycol. Various forms of PEG compounds are mixed with fatty acids and fatty alcohols to create a variety of substances that have diverse functions in cosmetics, including surfactants, binding agents (to keep ingredients blended), stabilizers, and emollients. See polyethylene glycol.

PEG-80 sorbitan laurate. Mild surfactant. See surfactant.

Pelargonium graveolens oil. See geranium oil.

pellitory. See Parietaria officinalis extract.

pentadecalactone. Synthetic fragrance used in cosmetics.

pentasodium penetate. Used as a chelating agent in cosmetics to prevent varying mineral components from binding together and negatively affecting the formulation.

peony root extract. There is research showing that the root of the peony plant can have anticancer properties as well as antioxidant properties (Sources: Cancer Letters, December 2001, pages 17–24; Archives of Pharmaceutical Research, April 2001, pages 105–108; and Chemical and Pharmaceutical Bulletin, January 2001, pages 69–72). However, there is no research showing it to have that benefit for skin (Source: Natural Medicines Comprehensive Database, www.naturaldatabase.com).

peppermint. Both the oil and the extract can have antimicrobial properties (Source: Journal of Agricultural and Food Chemistry, July 2002, pages 3943–3946), but they can also have an irritating, sensitizing effect on skin (Source: Natural Medicines Comprehensive Database, www.naturaldatabase.com). See counter-irritant.

peptide. A short chain of amino acids. This is in contrast to proteins, which are long chains of amino acids. In the body, peptides regulate the activity of other molecules such as proteins. This regulation is achieved by interaction of the peptide with the target molecule. Peptides have many functions, as some can have hormonal activity and others antibiotic activity. Whether peptides can have benefit when applied topically to skin for wound healing, skin barrier repair, or as disinfectants is difficult to ascertain, as they generally cannot penetrate skin and remain stable (Source: Biotechniques, July 2002, pages 190–192).

perfluoropolymethylisopropyl ether. Film-forming agent. See film-forming agent.

Perilla ocymoides oil. Derived from the seeds of the Perilla ocymoides plant. Perilla contains multiple flavones and the oil is high in alpha-linolenic acid. It has antioxidant and anti-cancer properties; however it may also be a significant skin irritant (Source: Natural Medicines Comprehensive Database, www.naturaldatabase.com).

periwinkle extract. There is no research showing this extract to have benefit for skin. It is not to be confused with Madagascar periwinkle, Catharanthus roseus, that has anti-tumor properties (Sources: Oncologist, 2000, volume 5, number 3, pages 185–198; and Journal of Agricultural Food Chemistry, November 2001, pages 5165–5170). However, Madagascar periwinkle is considered toxic and has limited use for cancer treatment (Sources: Natural Medicines Comprehensive Database, www.naturaldatabase.com; and FDA Poisonous Plant Database, www.fda.gov).

permanent lipstick.  This procedure can give a definite shape to your lips and make them appear fuller. The natural pigmentation of the lips can be enhanced.

permanent makeup.  Permanent make up is a non-surgical method of applying eyeliner, eyebrows and full lip color that can last for years. This is resorted to by women who want to add definition to their facial features or those who want to look good all the time sans the hassles of applying make up everyday. Permanent make up works wonders on burn patients and cancer patients or those who want to cover scars.

Persea gratissima oil. See avocado oil.

petitgrain mandarin. See mandarin orange.

petrolatum. Vaseline is pure petrolatum. For some unknown and unsubstantiated reason, petrolatum has attained a negative image in regard to skin care, despite good research to the contrary. Topical application of petrolatum can help the skin's outer layer recover from damage, reduce inflammation, and generally heal the skin (Source: Acta Dermato-Venereologica, November-December 2000, pages 412–415). See also mineral oil.

Pfaffia paniculata extract. Also known as suma extract and Brazilian ginseng. There is a small amount of research showing it to have anti-inflammatory properties (Source: Natural Medicines Comprehensive Database, www.naturaldatabase.com).

PHA. See polyhydroxy acid.

Phellodendron amurense extract. Extract of the Amur corktree; it can have anti-inflammatory and antifungal benefits (Sources: Journal of Antimicrobial Chemotherapy, May 1999, pages 667–674; and Fitoterapia, March 2001, pages 221–229).

phenoxyethanol. Common cosmetic preservative that is considered one of the less irritating ones to use in formulations. It does not release formaldehyde. See preservatives.

phenyl trimethicone. Silicone with a drier finish than dimethicone. See silicone.

phenylalanine. See amino acid.

phosphatidylcholine. The active ingredient found in lecithin. Every cell membrane in the body requires phosphatidylcholine (PC). It is also a major source of the neurotransmitter acetylcholine. Acetylcholine is used by the brain in areas that are involved in long-term planning, concentration, and focus. But all of this information is associated with ingesting PC, not putting it on the skin. PC is considered a very good water-binding agent and aids in the penetration of other ingredients into the skin. It absorbs well without feeling greasy or heavy (though other ingredients can perform similarly, including glycerin, ceramides, and hyaluronic acid). (Sources: Skin Pharmacology and Applied Skin Physiology, September-October 1999, pages 235–246; and Journal of Controlled Release, March 29, 1999, pages 207–214.) See lecithin, and water-binding agent.

phospholipid. Type of lipid (fat) composed of glycerol, fatty acids, and phosphate. Phospholipids are essential to the function of cell membranes by providing a stable surrounding structure. Lecithin and cholesterol are phosopholipids. See glyceryl ester, and natural moisturizing factors.

phosphoric acid. Used as a pH adjuster in cosmetic and skin-care products.

photosensitizer. Ingredients that can cause the skin to have an irritated or inflamed reaction when exposed to sunlight.

Phyllanthus emblica fruit extract. Has antioxidant and anti-inflammatory properties (Sources: Journal of Ethnopharmacology, May 2000, pages 171–176; and Planta Medica, December 1997, pages 518–524).

phytic acid. A component of plants that has antioxidant properties.

phytoalexins. Antimicrobial substances that are produced by a plant in response to infection by fungi or bacteria and that help to defend the plant by inhibiting the growth of invading microbes. Phytoalexins can also be potent antioxidants, and the combination of those two properties is thought to have benefit for skin, particularly for wound healing (Sources: Free Radical Research, June 2002, pages 621–631; and Biochemical Pharmacology, January 2002, pages 99–104). How that relates to daily skin care or wrinkles is unknown, but it is probably a good antioxidant for skin.

phytoestrogen. See plant estrogen.

phytol. Subcomponent of vitamin E and also a component of chlorophyll. It has antioxidant properties, but there is limited research about phytol having any effect on skin.

phytonadione. See vitamin K.

Phytoplenolin. Trade name for the plant extract Centipeda cunninghami. See Centipeda cunninghami extract.

phytosterol. Cholesterol-like molecules found in all plant foods, with the highest concentrations occurring in vegetable oils. Phytosterols in the natural diet may lower cholesterol (Sources: Annual Reviews of Nutrition, 2002, volume 22, pages 533–549; and Metabolism, May 2002, pages 652–656). However, regarding topical application, there is research showing that the high lipid content of phytosterols can make the skin extremely sensitive to light (Source: Photochemistry and Photobiology, September 1997, pages 316–325).

pilewort extract. See Ranunculus ficaria extract.

Pimpinella anisum. See anise.

pine cone extract. Components of this extract, specifically linolenic and linoleic acid, can have antioxidant properties (Source: Tree Physiology, June 2002, pages 661–666) and antibacterial properties for skin (Source: International Journal of Food Microbiology, May 2000, pages 3–12).

pine oil. Can have disinfectant properties (Source: Antimicrobial Agents and Chemotherapy, December 1997, pages 2770–2772), but it can also be a potent skin irritant and should never be used on abraded or chafed skin.

pineapple extract. Contains the enzyme bromelain, which can break down the connecting layers between skin cells to exfoliate skin. However, bromelain used alone is a more effective source of exfoliation, without the other irritating properties of the pineapple. See bromelain.

pink blush.  Used to accent cheekbones and provide luminous pink color.
The method of applying blush differs with the facial shape and the right application of blusher can make your face look longer or wider

pink lipstick  A waxy solid usually colored cosmetic in stick form for the lips. A very light film of pink or red lipstick gives you the look of that carefree beauty that every woman yearns for.

Pinus lambertiana wood extract. Pine extract that may have skin-sensitizing properties (Source: Botanical Dermatology Database, http://bodd.cf.ac.uk/index.html).

Pinus sylvestris extract. See pine cone extract.

Piper nigrum. See black pepper.

pistachio seed oil. An emollient plant oil with uses similar to peanut oil in cosmetics.

Pistacia vera seed oil. See pistachio seed oil.

placenta extract. Obtained from the afterbirth of animals, it is supposed to have rejuvenating properties for skin, but this claim has never been proven in research of any kind. Much like any part of a human or animal body, the placenta is a source of proteins and amino acids that have water-binding and antioxidant properties (Sources: Placenta, July 2002, pages 497–502; and Bioscience, Biotechnology, and Biochemistry, November 2000, pages 2478–2481). These are helpful for skin, but no more so than hundreds of other ingredients with similar or superior attributes. Due to the concern about Mad Cow Disease, ingredients of this nature are best avoided.

placenta protein. Protein that works like other proteins on skin, regardless of the source. It is just a good water-binding agent. See placenta, and protein.

placental enzymes. Obtained from either human or animal placentas. See placenta extract, and placental protein.

placental lipid. A lipid obtained from either human or animal placentas. See placenta extract, and placental protein.

placental protein. Obtained from either human or animal placentas, and used in cosmetics with varying, though completely unsubstantiated, claims about miraculous effects on skin. Animal- and human-derived ingredients are prohibited from use under the provisions of the European Union Cosmetics Directive (www.colipa.com/publication_17.html). For animal-derived ingredients, this directive is based on concerns about transmission of bovine spongiform encephalopathy (Mad Cow Disease); for human-derived ingredients the concern is viral diseases such as human immunodeficiency virus (HIV) (Source: International Journal of Toxicology, 2002, volume 21, Supplement 1, pages 81–91). There is no way to know from a cosmetic ingredient label what the source of the extract is. See placenta extract.

plant estrogen. Current understanding regarding oral supplements of plant estrogens is that they may work by interfering with the body's own estrogen, thus preventing it from being out of balance. Plant estrogens may fool the body into thinking it has the right balance of this hormone by filling the receptor areas on cells sensitive to human estrogen. If the body has too much estrogen, the plant estrogen may prevent the body from using it (thereby preventing estrogen-related cancers); if the body has too little estrogen (as during the stages of menopause), plant estrogen might make the body think it has more, thus reducing some of the more uncomfortable side effects. There is little information about how much estrogen-laden food a woman must consume (and for how long) to reduce or eliminate the effects of menopause. In other words, adding estrogen-rich foods or supplements to your diet won't necessarily prevent breast cancer, heart attack, osteoporosis, or hot flashes. There are also studies that have shown no improvement or benefit from dietary estrogens (Sources: Journal of Clinical Endocrinology & Metabolism, January 2002, pages 118–121; and Toxicological Science, February 2002, pages 228–238), although these were hardly sweeping or conclusive reviews.

Clearly, this is a health issue that needs to be examined more closely. But what about plant estrogens used in creams and applied topically? There is no research showing that plant estrogens can provide any benefit when applied topically to skin. But even if there were a benefit, how much would you need to rub on your skin to obtain it? Moreover, when it comes to cosmetics or skin-care products, there is no way to know how much of a plant estrogen extract is being used, or how active it remains in a manufactured product. More to the point, because the cosmetics and natural-supplement industries are not regulated, there is no way to really know what you are getting.

plum extract. Extract of Prunus americana that may have antioxidant activity when applied topically (Source: Phytotherapy Research, February 2002, pages 63–65).

Plumeria alba flower extract. Used as a fragrance in cosmetics.

Pogostemon cablin. See patchouli.

Polianthes tuberosa extract. Limited research has shown that the extract from this tuberous plant can have water-binding and antioxidant properties (Source: Phytochemistry, April 196, pages 1517–1521).

poloxamers. See surfactant.

polycaprolactone. Biodegradable thermoplastic polymer derived from the chemical synthesis of crude oil. It may have application in supporting skin-tissue growth for the purposes of skin grafts (Source: Tissue Engineering, August 2001, pages 441–455).

polyethylene glycol. Also listed as PEG on ingredient labels, polyethylene glycol is an ingredient that self-proclaimed "natural" Web sites have attempted to make notorious and evil. They gain a great deal of attention by attributing horror stories to PEG, associating it with antifreeze (however, antifreeze is ethylene glycol, not polyethylene glycol), and there is no research indicating that PEG compounds pose any problem for skin. Quite the contrary: PEGs have no known skin toxicity and can be used on skin with great results (Sources: Advanced Drug Delivery Reviews, June 2002, pages 587–606; and Cancer Research, June 2002, pages 3138–3143). The only negative research for this ingredient indicates that large quantities given orally to rats can cause tumors, but that is unrelated to topical application.

Polyethylene, when it is not combined with glycol, is the most common form of plastic used in the world. It is flexible and has a smooth, waxy feel. When ground up, the small particles are used in scrubs as a gentle abrasive. When mixed with glycol, it becomes a viscous liquid. In the minuscule amounts used in cosmetics, it helps keep products stable and performs functions similar to glycerin. Because polyethylene glycol can penetrate skin, it is also a vehicle that helps deliver other ingredients deeper into the skin. It is even used internally in medical procedures to flush and clean the intestinal tract. See propylene glycol.

polyglucuronic acid. See film-forming agent.

polyglycerol monostearate. Used as an emollient and thickening agent in cosmetics. See glyceryl ester.

polyglycerol polyricinoleate. Used as an emollient and thickening agent in cosmetics. See glyceryl ester.

polyglyceryl methacrylate. See film-forming agent.

polyglyceryl-2 caprate. Used as an emollient and thickening agent in cosmetics. See glyceryl ester.

Polygonum cuspidatum root extract. Extract of the Japanese knotweed plant. When eaten it may have weak estrogenic activity (Source: Bioorganic and Medicinal Chemistry Letters, July 2001, pages 1839–1842) and antitumor activity (Source: Journal of Nutrition, June 2001, pages 1844–1849). It also has antioxidant properties (Source: Biological & Pharmaceutical Bulletin, January 1995, pages 162–166).

polyhydroxy acid. Because alpha hydroxy acids (AHAs) may be irritating to skin, the search for an effective form of AHA or an extra ingredient that can enhance performance and reduce irritation is an active issue. Gluconolactone and lactobionic acid are types of polyhydroxy acid (PHA) that are supposed to be as effective as AHAs but less irritating (NeoStrata is the company that holds the patent on glycolic acid as an antiwrinkle agent, as well as a patent for gluconolactone for reducing the appearance of wrinkles). Gluconolactone and lactobionic acid are chemically and functionally similar to AHAs. The significant difference between them is that gluconolactone and lactobionic acid have larger molecular structures, which limits their ability to penetrate into the skin, resulting in a reduction of irritating side-effects. This reduced absorption into the skin supposedly doesn't hamper their effectiveness. Does that mean gluconolactone and lactobionic acid are better for your skin than AHAs in the form of glycolic acid or lactic acid? According to an Internet-published class lecture by Dr. Mark G. Rubin (Source: http://128.11.40.183/lasernews/rubin_lecture/21.html), a board-certified dermatologist and assistant clinical professor of dermatology at the University of California, San Diego, research on gluconolactone demonstrated only a "6% decrease in dermal penetration" in comparison to glycolic acid, which "isn't a dramatic improvement." Gluconolactone may be slightly less irritating for some skin types but this isn't quite the magic bullet for exfoliation that beauty magazines and some cosmetics companies have been extolling. There is no independent research information available about lactobionic acid.

polyquaterniums. Group of ingredients used primarily in hair-care products due to their antistatic and film-forming properties. They can have water-binding properties for skin due to the sheer "plastic" film layer they create on skin.

polysorbates. Fatty acids that are used as emollients and thickening agents in cosmetics. See fatty acid.

polyvinyl alcohol. See plasticizing agents.

polyvinylpyrrolidone. Usually listed on ingredient labels as PVP or PVP copolymer, it is one of the primary ingredients used in hairstyling products to hold hair in place. When present in minuscule amounts in skin-care products, it places an imperceptible film over the skin that is considered to be water-binding and that helps give the appearance of firmer skin. It can be a skin sensitizer for some individuals. See also film-forming agent.

pomegranate extract. Contains ellagic acid, and is considered effective as an anticarcinogen and antioxidant when taken orally. There is no research showing what effect, if any, this extract can have on skin (Sources: Journal of Agricultural Food Chemistry, January 2002, pages 81–86, and 166–171; and International Journal of Oncology, May 2002, pages 983–986).

Pongamia glabra seed oil. Has antimicrobial properties (Source: Archives of Andrology, January-February 2002, pages 9–13).

Pongamia pinnata extract. Can have anti-inflammatory properties (Source: Journal of Ethnopharmacology, December 2001, pages 151–157).

poppy seeds. Can have analgesic properties when applied topically.

Poria cocos extract. Derived from a mushroom, this extract has antioxidant and anti-inflammatory properties (Sources: Life Sciences, January 2002, pages 1023–1033; and Journal of Ethnopharmacology, November 2000, pages 61–69). Also known as Hoelen and Fu ling.

Porphyra umbilicalis. Form of seaweed. See algae.

Porphyridium cruentum. Type of red algae. See algae.

Portulaca Oleracea extract. May have anti-inflammatory or analgesic properties (Source: Journal of Ethnopharmacology, July 2001, pages 171-176 and December 2000, pages 445-451).

potassium. Important in diet and present in such fruits and bananas and citrus. It is also an earth mineral that has absorbent properties and some disinfecting properties, but can also be a skin irritant.

potassium cetyl phosphate. Used as a detergent cleansing agent. See surfactant.

potassium hydroxide. Also known as lye, it's a highly alkaline ingredient used in small amounts in cosmetics to modulate the pH of a product. It is also used as a cleansing agent in some cleansers. In higher concentrations it is a significant skin irritant.

potassium myristate. Detergent cleansing agent that is a constituent of soap; it can be drying and sensitizing for some skin types. See surfactant.

potassium thiocyanate. Chemically, a salt that can be a potent skin irritant, though it can also have antibacterial properties for skin.

Poterium officinale root extract. Derived from the garden burnet plant. See Sanguisorba officinalis.

powder brush.  Most quality brushes will be made from natural hairs like squirrel, pony, sable or even goat hair and shouldn't shed when fluffed or tugged at lightly.

Powder Eyeliner. Powder eyeliner gives a more diffused rim of dark halo around the lashline compared to the kohl liner. It's usually applied and blended with eyeshadow for a sultry, smoky eye effect. Regular dark eyeshadows like coal black and deep browns are used as powder eyeliners.

pregnenolone acetate. Precursor to other hormones, it can affect levels of progesterone and estrogen in the body when taken orally. When applied to skin it may work as a water-binding agent. There is no information about whether absorption of this through skin is possible.

preservatives. Substances used in cosmetics to prevent bacterial and microbial contamination of products. While there is definitely a risk of irritation from these types of ingredients, the risk to skin and eyes from using a contaminated product is considered by many scientists to be even greater.

Pressed Mineral. Blush Mineral blushes offer a beautiful hint of color that can be applied to the cheeks and temples for a healthy translucent glow.  Safe to use on eyes or lips.

prickly pear extract. There is no research showing it to be effective for skin when applied topically, though it may have water-binding properties (Source: Plant Foods for Human Nutrition, 1998, volume 52, number 3, pages 263–270).

primrose. See Primula veris extract.

Primula veris extract. Derived from primrose or cowslip plants. It has no known benefit for skin, though it does contain flavones and may have antioxidant properties (Source: Journal of Chromatography A, February 2000, pages 453–462).

pristane. Technically tetramethylpentadecane or pentadecane. It is a component of mineral oil, shark oil, or plant oil. It is used as an emollient in cosmetics.

progesterone USP. A study published in the American Journal of Obstetrics and Gynecology (June 1999, pages 1504–1511) states that "In order to obtain the proper (effective) serum levels with use of a progesterone cream, the cream needs to have an adequate amount of progesterone in it [at least 30 milligrams per gram]. Many over the counter creams have little [for example, 5 milligrams per ounce] or none at all. The creams that are made from Mexican yams are not metabolized to progesterone by women. The cream used in the above study (Pro-Gest) contains pure United States Pharmacopoeia [USP] progesterone." Dr. John Lee, an author and longtime proponent of topically applied progesterone, explains that "The USP progesterone used for hormone replacement comes from plant fats and oils, usually a substance called diosgenin, which is extracted from a very specific type of wild yam that grows in Mexico, or from soybeans. In the laboratory, diosgenin is chemically synthesized into real human progesterone. Some companies are trying to sell … ‘wild yam extract' [or other plant extracts] … claiming that the body will then convert it into hormones as needed. While we know this can be done in the laboratory, there is no evidence that this conversion takes place in the human body." Dr. Lee is quick to explain that he doesn't sell any of these products and receives no profit from their sale. He also does not recommend the use of natural progesterone creams with any other active hormones or herbs.

proline. See amino acid.

propagermanium. See germanium.

propolis. Brownish, resinous material that is collected by bees and used to construct the hive. It has antibacterial and anti-inflammatory properties for skin (Source: Antimicrobial Agents and Chemotherapy, May 2002, pages 1302–1309).

propylene glycol. Along with other glycols and glycerol, this is a humectant or humidifying and delivery ingredient used in cosmetics. There are Web sites and spam e-mails stating that propylene glycol is really industrial antifreeze and that it is the major ingredient in brake and hydraulic fluids. These sites also state that tests show it to be a strong skin irritant. They further point out that the Material Safety Data Sheet (MSDS) on propylene glycol warns users to avoid skin contact because systemically (in the body) it can cause liver abnormalities and kidney damage. As ominous as this sounds, it is so far from the reality of cosmetic formulations that almost none of it holds any water or poses real concern. It is important to realize that the MSDS sheets are talking about 100% concentrations of a substance. Even water and salt have frightening comments regarding their safety according to the MSDS. In cosmetics propylene glycol is used in only the smallest amounts to keep products from melting in high heat or freezing when it is cold. It also helps active ingredients penetrate the skin. In the minute amounts used in cosmetics, it is not a concern in the least. Women are not suffering from liver problems because of propylene glycol in cosmetics. And finally, according to the U.S. Department of Health and Human Services, within the Public Health Services Agency for Toxic Substances and Disease Registry, "studies have not shown these chemicals [propylene or the other glycols as used in cosmetics] to be carcinogens" (Source: www.atsdr.cdc.gov).

propylparaben. See parabens.

proteases. Enzymes that are part of a process that causes the breakdown of amino acids and proteins in skin (Source: www.chemistry-info.net/). There is research showing that proteases, when applied topically to skin, can reduce the visible scaling associated with dry, flaky skin (Source: Archives of Dermatological Research, November 2001, pages 500–507). Whether proteases can be of benefit for wound healing when applied topically is unclear (Source: Experimental Dermatology, October 2001, pages 337–348).

protein. Proteins are fundamental components of all living cells and include a diverse range of biological substances, such as enzymes, hormones, and antibodies, that are necessary for the proper functioning of any organism, plant, or animal. The human body contains perhaps 100,000 different proteins, each composed of an assortment of 20 or so amino acids. The sequence of these amino acids determines the unique properties of each protein, such as, for example, its role as an enzyme acting as a catalyst for a specific biochemical reaction. If even one of the essential amino acids is missing, the protein cannot be formed. This fact is well known to nutritionists because ensuring an adequate supply of essential amino acids is important in determining the nutritional value of proteins in the diet. Components of proteins can have varying benefits for skin, but overall they are used for their water-binding and emollient properties.

Protol. Trade name for mineral oil. See mineral oil.

Prunella vulgaris. See self-heal.

Prunus americana. See plum extract.

Prunus domestica seed extract. See plum extract.

Prunus dulcis. See almond oil.

Pseudopterogorgia elisabethae. See sea whip extract.

Psidium guajava. See guava extract.

Pueraria lobata. See kudzu root.

pullulan. Produced by black yeast, pullulan is a glucan gum that contains polysaccharides, which makes it a good water-binding agent, thickening agent, and antioxidant. See beta-glucan, and mucopolysaccharide.

Punica granatum extract. See pomegranate.

pure essential oil.  A volatile material derived from odorous plant materials from a single botanical form. As such, Essential oils generally constitute the odorous principles of the plants in which they exist. Essential oils are either distilled (water, steam or dry) or expressed. Because Essential oils are highly concentrated, care should be used when handling them. We carry hundreds of essential oils, ranging from Agarwood to Ylang Ylang.

purified water. See deionized water.

PVP. See polyvinylpyrrolidone.

PVP copolymer. See polyvinylpyrrolidone.

pycnogenol. There is a great deal of research on pycnogenol, a plant-derived substance found in everything from pine bark to apples, cocoa beans, unripe strawberries, peanut skin, grape seeds, and red wine. However, most of the research dates back to 1990 and earlier (Source: U.S. Patent No. 4,698,360 entitled "Plant Extract with a Proanthocyanidins Content as Therapeutic Agent Having Radical Scavenging Effect and Use Thereof"). There are studies supporting the notion that pycnogenol is a potent antioxidant with strong free-radical-scavenging properties (Source: Free Radical Biology and Medicine, September 1999, pages 704–724). However, there isn't any research showing that it will have any effect on wrinkles. See antioxidant.

pyridoxine hydrochloride (HCL). Scientific name for vitamin B6; may have antibacterial and antioxidant benefits for skin when applied topically.

Pyrus cydonia. See quince seed.