Yes, body hair can be used to test for the five standard drug classes, though body hair growth patterns are different than head hair. Most body hair is replaced within approximately one year. This means a test done with body hair will be reported as drug usage during approximately a one year time frame.
A sample of body hair an inch and a half in length will give you a history of about 5-6 months, as body hair grows more slowly than hair on the head. This also means that it takes longer for drugs to grow out into the body hair than the head hair.
In addition, body hair may be used as a substitute to head hair. In the rare case where no hair is collectible, complete urine/adulteration testing may be utilized.