Page 205 - Cosmetology

Codium tomentosum extract. See algae.

coenzyme Q10. Only a handful of studies have shown coenzyme Q10 (CoQ10) to have any effect on
wrinkles. However, neither of these studies was double-blind or placebo-controlled, so there is no way to tell
whether other formulations could net the same results. There is also research showing that sun exposure
depletes the presence of CoQ10 in the skin. This isn't surprising, because lots of the skin's components
become diminished upon exposure to the sun. But whether or not taking CoQ10 supplements or applying
them to skin stops or alters sun damage is not known.

Coffea arabica extract. Coffea arabica is the coffee plant, and there is research showing coffee extract to
have antioxidant properties.

Cola acuminata seed extract. See kola nut.

Coleus barbatus. Member of the mint family; can be a skin irritant. See counter-irritant.

Coleus barbatus extract. See Plectranthus barbatus extract reviewed on page 6.

collagen. A major component of skin that gives it structure. Sun damage causes collagen in skin to
deteriorate. Collagen is derived from animal sources but plant derivatives that act like collagen (pseudo-
collagen) are also used. In any form, collagen is a good water-binding agent. Collagen in cosmetics,
regardless of the source, has never been shown to have a direct effect on producing or building collagen in
skin.

collagen amino acid. Amino acids hydrolyzed from collagen. These have good water-binding properties for
skin. See amino acid and natural moisturizing factors.

colloidal oatmeal. See oatmeal.

colloidal silver. Refers to ground-up silver suspended in solution. See silver.

colostrum. The clear/cloudy "pre-milk" that female mammals secrete prior to producing milk. Colostrum
contains immunoglobulins (disease resistance factors). While there is a small body of evidence indicating
that adult consumption of colostrum may have disease-fighting potential, this is hardly substantiated, and
there is no known benefit when colostrum is applied topically to skin. The only study that does exist showed
colostrum to have no wound-healing function on skin.

colostrum. The thick, yellowish fluid secreted by the mammary glands prior to and during the first few days
after birth, before actual milk is produced by the breast. Colostrum is a highly nutritive substance, loaded
with proteins, immune-building substances, and growth factors. Colostrum’s primary purpose is to supply
antibodies and growth factors to help newborns fight viruses and bacteria and to jump-start the growth of
muscle, bone, and tissue. There is some research showing it to have benefit when applied topically for
wound healing but it is minor at best and some of the research showed it was not helpful. Nonetheless,
wrinkles and aging skin is not equivalent to a wound. The source of colostrum in supplements and skin-care
products is bovine.

coltsfoot. According to The PDR Family Guide to Natural Medicines & Healing Therapies and a German
Commission E Monograph, coltsfoot is potentially carcinogenic due to its pyrrolizidine alkaloid content and is
not recommended for repeated use on skin.

comfrey extract. Several studies have shown that comfrey extract can have carcinogenic or toxic properties
when taken orally. Whether those properties translate to topical application of the extract is unknown, but its
alkaloid content makes it a potential skin irritant.

Commiphora myrrha extract. See myrrh.

Commiphora wightii extract. Has been shown to have cytotoxic components that may have a toxic effect
on skin cells.

coneflower. See echinacea.

Conium maculatum. Also known as poison hemlock. When taken orally all parts of hemlock, including