Chemical depilatory

A chemical depilatory is a cosmetic preparation used to remove hair from the skin. Common active ingredients are salts of thioglycolic acid and thiolactic acids. These compounds break the disulfide bonds in keratin and also hydrolyze the hair so that it is easily removed. Formerly, sulfides such as strontium sulfide were used, but due to their unpleasant odor, they have been replaced by thiols.[1]

The main chemical reaction effected by the thioglycolate is:

2 HSCH2CO2H (thioglycolic acid) + R-S-S-R (cystine) → HO2CCH2-S-S-CH2CO2H (dithiodiglycolic acid) + 2 RSH (cysteine)

Chemical depilatories contain 5–6% calcium thioglycolate in a cream 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, and the hair grows back.[2]

Chemical depilatories are available in gel, cream, lotion, aerosol, roll-on, and powder forms. Common brands include Nair, Magic Shave and Veet.

Depilatory ointments, or plasters, were known to Greek and Roman authors as psilothrum.[3]

References

  1. ^ "Hair Preparations", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), 2007, doi:10.1002/14356007.a12_571.pub2
  2. ^ Arza Seidel; et al., eds. (2013), Kirk-Othmer Chemical Technology of Cosmetics, p. 44
  3. ^ "PSILOTHRUM", Dictionary of Greek and Roman Antiquities (3rd ed.), 1890
Bikini waxing

Bikini waxing is the removal of pubic hair using a special wax, which can be hot or cold, that adheres to hairs and pulls them out when the wax is removed quickly from the skin, usually with a cloth strip. While the practice is mainly associated with women, male waxing is sometimes done to remove men's pubic hair.A bikini line is the area of the upper leg and inner thigh in which pubic hair grows that is normally not covered by the bottom part of a swimsuit. In some cultures, visible pubic hair in this region is disliked and/or considered embarrassing and so it is sometimes removed. However, some people remove pubic hair that will not be exposed for reasons like aesthetics, personal grooming and hygiene, culture, religion or fashion.

Hair tourniquet

Hair tourniquet is a medical condition wherein a hair or other thread becomes tied around a toe or finger or male genital tightly, so as to put the digit at risk of damage. Occasionally, this is known as toe tourniquet.

The problem usually arises in babies and small children when hairs and thread are lost loosely inside socks. They can become spontaneously tied round a toe and will tend to tighten with wriggling. Natural hair is much more likely to undergo this phenomenon than spun thread.

Incidents similar to this can also occur during sleep, usually under duvets or sheets which have loose threads which can constrict the toes.

Magic Shave

Magic Shave is a brand series of chemical depilatory shaving-related products and other personal care products. It was created by Loreal's skincare division targeting "people of color", Softsheen and Carson.

Nad's

Nad's is an Australian trademark of internationally sold waxing hair removal products, although chemical depilatory, skin-care and other products are also sold under the name.

Nazirite

In the Hebrew Bible, a nazirite or nazarite is one who voluntarily took a vow described in Numbers 6:1–21. "Nazarite" comes from the Hebrew word נזיר nazir meaning "consecrated" or "separated". This vow required the person to:

Abstain from wine, wine vinegar, grapes, raisins, intoxicating liquors, vinegar made from such substances, and eating or drinking any substance that contains any trace of grapes.

Refrain from cutting the hair on one's head; but to allow the locks of the head's hair to grow.

Not to become ritually impure by contact with corpses or graves, even those of family members.After following these requirements for a designated interval (which would be specified in the individual's vow), the person would immerse in a mikveh and make three offerings: a lamb as a burnt offering (olah), a ewe as a sin-offering (hatat), and a ram as a peace offering (shelamim), in addition to a basket of unleavened bread, grain offerings and drink offerings, which accompanied the peace offering. They would also shave their head in the outer courtyard of the Jerusalem Temple and then place the hair on the same fire as the peace offering. (Numbers 6:18)

The nazirite is described as being "holy unto YHWH" (Numbers 6:8), yet at the same time must bring a sin offering. This has led to divergent approaches to the nazirite in the Talmud, and later authorities, with some viewing the nazirite as an ideal, and others viewing him as a sinner.

Phalloplasty

Phalloplasty is the construction or reconstruction of a penis, or the artificial modification of the penis by surgery. The term phalloplasty is also occasionally used to refer to penis enlargement.

The first phalloplasty done for the purposes of sexual reassignment was performed on Michael Dillon, a trans man, in 1946 by Dr. Harold Gillies, which is documented in Pagan Kennedy's book The First Man-Made Man.

Pseudofolliculitis barbae

Pseudofolliculitis barbae (PFB), also known as barber's itch, folliculitis barbae traumatica, razor bumps, scarring pseudofolliculitis of the beard, and shave bumps, is a medical term for persistent irritation caused by shaving. Pseudofolliculitis barbae was first described in 1956.

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 is miscible with polar organic solvents.

Veet

Veet, formerly called Neet and Immac, is a current trademark of chemical depilatory internationally sold products manufactured by Reckitt Benckiser. Hair removal creams, mousses and gels, and waxes are produced under this brand. It has previously created similar products under the names Neet and Immac.

Veet's hair removal products contain thioglycolic acid and potassium hydroxide. These ingredients react to generate the depilatory chemical potassium thioglycolate, which according to the company, increases hair loss. The effect is to break the disulfide bonds of the keratin molecules in hair. This reduces the tensile strength of the keratin so greatly that the hair can be wiped away.

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