Gurpreet S. Ahluwalia
The Gillette Company, a wholly owned subsidiary of The P&G Company,
Needham, MA, USA
10.1 Introduction 240
10.2 Physical Methods 240
10.2.1 Shaving 240
10.2.2 Epilation 241
10.3 Chemical Methods 242
10.3.1 Depilatory Creams 242
10.3.2 Enzyme Depilatories 243
10.3.3 Cosmeceuticals for Hair Reduction 244
10.3.4 Pharmaceuticals (Rx) for Hair-Growth Control 244
10.3.4.1 Hormonal Treatments 244
10.3.4.2 Vaniqa (Eflornithine), a Topical Drug (Rx)
for Unwanted Facial Hair 245
10.4 Energy-Dependent Processes 246
10.4.1 Electro-epilation 246
10.4.2 Laser and Light-Based Systems 246
10.4.3 Photodynamic Therapy for Hair Removal 247
10.5 Biochemical Target-Based Hair-Growth Reduction 247
10.5.1 Patented Technologies on Hair-Growth Regulation 247
Gurpreet S. Ahluwalia (ed.), Cosmetic Applications of Laser and Light-Based Systems, 239-252,
© 2009 William Andrew Inc.
The main function of mammalian hair is to provide environmental protection. However, this function has now largely been lost in humans, in whom hair is retained or removed from various parts of the body essentially for cosmetic reasons. Though both men and women remove hair, it is the appearance of hair on a woman’s body that is perceived as unnatural. Women feel that hair does not belong to their body, except for the scalp, and constantly seek means to rid themselves of this unwanted hair. In Western culture, the hair-free body is the norm for women [1,2]. The issue of unwanted hair is further magnified, and takes on a whole new significance, for women who suffer from the presence of terminal hair on their face. The psychological aspects of having facial hair is extremely devastating to women, who will go to great lengths to hide the condition, as it is a condition accompanied by a significant psychosocial burden [3]. Hirsute patients treated in an endocrinologist’s practice are often the most grateful of all patients, who are satisfied with rather small improvements [4].
Generally, women rely on shaving, depilatory creams, bleaching, waxing, and plucking to remove unwanted hair. Lack of femininity, irritation, and nonperformance are some of the disadvantages that prevent these cosmetic methods of hair removal from being totally acceptable in this population. Moreover, these approaches provide only a short-lived or temporary effect. Even with these disadvantages, it has been estimated that women spend over $2.0 billion a year on cosmetic remedies for this problem. Among emerging technologies, laser-assisted hair removal has received much attention. The technology introduced about ten years ago has seen a tremendous growth, with the current worldwide revenue of about $2.8 billion (Medical Insight publication). Most of this revenue, however, represents the fee to the service providers paid by the consumer. Table 10.1 lists various hair-removal options available to the women.
Hair removal can be broadly put into two categories, depilation and epilation. The two terms are quite often used interchangeably in the scientific and the patent literature. Sted – man’s medical dictionary probably comes closest to defining them. Epilate is defined as “to extract a hair, to remove the hair from a part by forcible extraction…”. Depilate is defined as “to remove hair by any means.” An important distinction is that in epilation, the complete hair shaft is removed from its roots, whereas, in depilation superfluous hair is removed and the hair-root is left undamaged.