The understanding about hair and hair follicle has improved tremendously in the last decade. But in terms of treatment options nothing much has changed apart from refinement of surgical techniques. As the percentage of men and women, who suffer from hair loss grows, proportionally, the number of products sold for hair loss also grows. These products (growth factors, stem cell preparation, vitamin pills, and peptides) are advertised widely in the media and on the net and by late night pitches via infomercials. They prey on those who may be concerned about recent or dramatic hair loss. We urge caution when considering these products and always maintain that be suspicious of treatments that offer a large benefit for very little in return. Usually these products do not have any scientific studies backing them.

How Many Hairs Does A Human Head Have ?

Each human typically has between 2 million to 5 million hairs on the body. A human head has anywhere between 100,000 and 150,000 hairs. The number, caliber and density per unit area varies with age, gender, and ethnicity. Oriental heads have most hairs and redheads have the least. Apart from the palms and soles almost all skin has follicles. But not all hair grows to the same length or at the same rate.

What Is The Density Of Hair On Scalp ?

Accurate quantitative analysis of scalp hair density is difficult and time consuming. Scalp possesses the greatest density of hair fibers 300 – 500/cm2 (different figures are quoted by different specialists ranging from 130-280/sqcm2), Chest about 100/cm2, Thigh about 50/cm2. Clinically when we look at the hair follicles on the back of the head we have an average density of 160 hairs per cm2.

How Does Hair Grow?

Hair grow in cycles which are not synchronized in human beings; each hair enters phases of growth cycle at a different time. There are three phases in hair growth cycle:

• Anagen – Growth Cycle, 2 to 8 years
• Catagen – Degradation phase of involution phase, 2 to 4 weeks
• Telogen – Resting phase, 2 to 4 months.After this the hair shaft is shed (Exogen)

How Is Hair Growth Regulated ?

The hormones called androgens are important control factors in hair growth and in inherited male and female patterns of hair loss. The androgen hormone testosterone and its metabolite dihydrotestosterone (DHT) are the key control factors:

• Testosterone is a key control factor in the growth of beard, underarm and pubic hair.
• Scalp hair loss is associated with presence of DHT in male and female pattern hair loss. DHT plus the presence and activity of hair loss gene(s) are the key factors underlying male and female pattern hair loss.
• The androgens mediate their effect by binding to the androgen receptors present in the follicle. The testosterone is converted to DHT by the action of the enzyme 5-Alpha reductase. The DHT then binds to the receptor and initiates its action.