Scientists believe they may have hit upon a cure for baldness – but it is not for the faint-hearted.
Researchers found they were able to regrow hair on the bald patches on people's heads by injecting them with a solution derived from their own blood.
The so-called "vampire" treatment involved taking blood from the patient and processing it in a machine that extracts "platelet-rich plasma" (PRP), which is then injected back into the head.
Scientists believe the solution then stimulates new stem cells below the skin which can aid the regrowth of hair.
Such "vampire" treatments are already used in some cosmetic procedures, where injections of PRP are used in an effort to reduce the effects of ageing on the face and hands.
The new treatment could have helped Elton John, who invested in a hair transplant.
The research, published in the latest edition of the British Journal of Dermatology, was conducted among a group of people suffering from alopecia areata, which affects about 2pc of the population.
However, the scientists believe it could also help those suffering more common varieties, such as male-pattern baldness. Dr Fabio Rinaldi said: "We think it can help to regrow hair on people with androgenic alopecia (male-pattern baldness). We believe it is the best treatment available, apart from surgery."
The study involved 45 patients, who received the injections on just one half of their head.
Some were given the PRP, some were given a more traditional steroid treatment, while others received a placebo.
A total of three treatments were given to each patient, once a month.
Hair growth was assessed by measuring the area where new hairs grew on the bald scalp. The PRP was found to lead to significant hair regrowth in the bald patches, compared with both the placebo and the steroid treatment.