Human hair growth
The three stages of hair growth are the anagen, catagen, and telogen phases. Each strand of hair on the human body is at its own stage of development. Once the cycle is complete, it restarts and a new strand of hair begins to form. The rate or speed of hair growth is about 1.25 centimetres or 0.5 inches per month, or about 15 centimetres or 6 inches per year.
Body Bags (film)
Richard Coberts is a middle-aged businessman who is very self-conscious about his thinning hair. This obsession has caused a rift between him and his long-suffering girlfriend Megan. Richard answers a television ad about a "miracle" hair transplant procedure, pays a visit to the office, and meets the shady Dr. Lock, who agrees to give Richard a solution to make his hair grow back. The next day, Richard wakes up and removes the bandage around his head, and is overjoyed to find that he has a full head of hair. But soon he becomes increasingly sick and fatigued, and finds his hair continuing to grow and, additionally, growing out of parts of his body, where hair does not normally grow. Trying to cut a hair off his mouth, he finds that it "screams", and, examining it under a magnifying glass, sees that it's alive and resembles a tiny serpent. He goes back to Dr. Lock for an explanation, but finds himself a prisoner as Dr. Lock explains that he and his entire staff are aliens from another planet, seeking out narcissistic human beings and planting seeds of "hair" to take over their bodies for consumption as part of their plan to spread their essence to Earth.