What name is given to the scientific study of hair?

The scientific study of hair is known as Trichology. It is a branch of dermatology (the study of skin). In fact, trichology is not only the scientific study of hair but is also the scientific study of the scalp.
A trichologist is a qualified professional who practices trichology. In other words, if you are facing any issues related to your hair such as hair fall, hair loss, baldness, premature graying, dandruff, dryness, thinning of hair, etc., a trichologist is the person you should consult.
A trichologist is not a medical doctor and is simply a qualified professional who works in the field of trichology. However, a trichologist is not the same as the hair stylist or beautician and has received an extensive training in the structure, function, and diseases of hair.
With the increased interest in hair care (and better looks), trichology is gaining widespread interest.