Page 247 - Cosmetology

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 . 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). 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, 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.

plasticizing agents. Ingredients that place a thin layer of plastic over the skin; typically these are used in
facial masks so they can be peeled off the skin. See film-forming agent.

plum extract. Extract of Prunus americana that may have antioxidant activity when applied topically.

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.

poloxamers. See surfactant.

polyacrylamide. See film-forming agent.

Polybutene. A polymer derived from mineral oil and used as a thickener and lubricant.

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.

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.
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