Page 223 - Cosmetology

Hydrastis canadenis. See goldenseal.

hydrocortisone. Hormone from the adrenal gland that can also be created synthetically. It has potent anti-
inflammatory properties for skin, but prolonged use can destroy collagen in the skin and cause skin fragility.

hydrocotyl extract. See Centella asiatica.

hydrogen peroxide. There is a great deal of current research showing that hydrogen peroxide is
problematic as a topical disinfectant because it can greatly reduce the production of healthy new skin cells.
Hydrogen peroxide is also a significant oxidizing agent, meaning that it generates free-radical damage.
While it can function as a disinfectant, the cumulative problems that can stem from impacting the skin with a
substance that is known to generate free-radical damage, impair the skin's healing process, cause cellular
destruction, and reduce optimal cell functioning are serious enough so that it is better to avoid its use.

hydrogenated castor oil hydroxystearate. Used as an emollient and thickening agent in cosmetics. See
glyceryl ester.

hydrogenated coco-glycerides. Used as an emollient and thickening agent in cosmetics. See glyceryl
ester.

hydrogenated didecene. A skin-conditioning agent derived from didecene, which is a hydrocarbon.
Hydrocarbons are organic compounds that contain only carbon or hydrogen. Examples of common
hydrocarbons include mineral oil, petroleum, and paraffin wax.

hydrogenated lecithin. See lecithin.

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

hydrogenated polydecene. Synthetic polymer that functions as an emollient and skin-conditioning agent.

hydrogenated polyisobutene. A synthetic polymer used as a skin-conditioning agent and emollient.

hydrolyzed actin. Form of protein that has water-binding properties for skin. See water-binding agent.

hydrolyzed conchiolin protein. A component of oyster shell. It can have water-binding properties for skin.
See protein.

Hydrolyzed jojoba esters. Essential fatty acids from the jojoba plant, broken down by water to form a new
complex with properties different from the original source. An analogy of this process is the manner in which
humans digest food to turn it into energy. Jojoba esters function as a skin conditioning agent.

hydrolyzed reticulin. Reticulin are a type of fibers found in skin and thought to be part of a systematic
network that surrounds collagen fibers and helps hold them together. There is no evidence that applying
reticulin externally to skin can have any effect on collagen whatsoever. Moreover, the hydrolyzing process
needed to mix reticulin into a skin-care product also alters its form, which may change or stop anything it
might do.

hydrolyzed silk. See silk.

Hydrolyzed vegetable protein. Composed of various protein substances derived from vegetables and
broken down by water to form a new complex with properties different from the original source. Used as a
water-binding agent.

hydroquinone. Substance that is known to successfully reduce the intensity of freckles, melasma, and
general brown patching by inhibiting melanin production. For continued and increased effectiveness it must
be used long term. Unprotected sun exposure should be avoided, because it reverses the effect of
hydroquinone by increasing melanin production. Occasionally, at higher concentrations, persons with a
darker skin type will experience increased pigmentation, but this is rare. It can cause mild skin irritation and
there is the possibility of an allergic reaction. Hydroquinone in 1% to 2% concentrations is available in over-
the-counter products; 4% concentrations are available by prescription only.