A chemical depilatory is a cosmetic preparation used to remove hair from the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different de ...

. Common active ingredients are salts of

thioglycolic acid Thioglycolic acid (TGA) is the organic compound HSCH2CO2H. TGA is often called mercaptoacetic acid (MAA). It contains both a thiol ( mercaptan) and carboxylic acid functional groups. It is a colorless liquid with a strongly unpleasant odor. TGA i ...

and

thiolactic acid Thiolactic acid is the organosulfur compound with the formula HSCH2CO2H. The molecule contains both carboxylic acid and thiol functional groups. It is structurally related to lactic acid by the interchange of SH for OH. It is a colorless oil. T ...

s. These compounds break the

disulfide bond In biochemistry, a disulfide (or disulphide in British English) refers to a functional group with the structure . The linkage is also called an SS-bond or sometimes a disulfide bridge and is usually derived by the coupling of two thiol groups. In ...

s in

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...

and also

hydrolyze Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis ...

the hair so that it is easily removed. Formerly, sulfides such as

strontium sulfide Strontium sulfide is the inorganic compound with the formula Sr S. It is a white solid. The compound is an intermediate in the conversion of strontium sulfate, the main strontium ore called celestite (or, more correctly, celestine), to other mor ...

were used, but due to their unpleasant odor, they have been replaced by

thiol In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl gro ...

s. The main chemical reaction effected by the thioglycolate is: : Chemical depilatories contain 5–6% calcium thioglycolate in a

cream Cream is a dairy product composed of the higher-fat layer skimmed from the top of milk before homogenization. In un-homogenized milk, the fat, which is less dense, eventually rises to the top. In the industrial production of cream, this process ...

base (to avoid runoff). Calcium hydroxide or strontium hydroxide maintain a pH of about 12. Hair destruction requires about 10 minutes. Depilation is followed by careful rinsing with water, and various conditioners are applied to restore the skin's pH to normal. Depilation does not destroy the

dermal papilla The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided in ...

, and the hair grows back. Chemical depilatories are available in

gel A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still dif ...

lotion Lotion is a low-viscosity topical preparation intended for application to the skin. By contrast, creams and gels have higher viscosity, typically due to lower water content. Lotions are applied to external skin with bare hands, a brush, a clean ...

, aerosol, roll-on, and

powder A powder is a dry, bulk solid composed of many very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms ''powder'' and '' granular'' are sometimes used to distin ...

forms. Common brands include

Nair The Nair , also known as Nayar, are a group of Indian Hindu castes, described by anthropologist Kathleen Gough as "not a unitary group but a named category of castes". The Nair include several castes and many subdivisions, not all of whom histo ...

Magic Shave Magic Shave is an American brand of chemical depilatory shaving-related products and other personal care products. It was created by Loreal's skincare division, Softsheen and Carson, in order to reduce skin inflammation, irritation and razor b ...

, and

Veet Veet, formerly called Neet and Immac, is a Canadian brand of chemical depilatory products manufactured by the British company Reckitt. Hair removal cream, Lotions, gel, mousse, and wax products are produced under this brand, with differing variant ...

. Chemical depilatories are indicated in the treatment of hirsutism in

polycystic ovary syndrome Polycystic ovary syndrome, or PCOS, is the most common endocrine disorder in women of reproductive age. The syndrome is named after the characteristic cysts which may form on the ovaries, though it is important to note that this is a sign and no ...

. Depilatory ointments, or plasters, were known to Greek and Roman authors as ''psilothrum''. In Jewish lore, King Solomon is said to have discovered a chemical depilatory made from a mixture of lime and water and

orpiment Orpiment is a deep-colored, orange-yellow arsenic sulfide mineral with formula . It is found in volcanic fumaroles, low-temperature hydrothermal veins, and hot springs and is formed both by sublimation and as a byproduct of the decay of anothe ...

(

arsenic trisulfide Arsenic trisulfide is the inorganic compound with the formula . It is a dark yellow solid that is insoluble in water. It also occurs as the mineral orpiment (Latin: auripigmentum), which has been used as a pigment called King's yellow. It is produ ...

). Colloquy of the Queen of Sheba, taken from the Aramaic ''Targum Sheni of Megillat Esther''.

References

{{DEFAULTSORT:Chemical Depilatory Hair removal