Four years ago Rob Dawson, a British GP (general practitioner, or family doctor), came across a startling set of figures from a local needle exchange programme: the largest single group of drug users visiting the exchange -- 60 percent -- were not heroin addicts, but intramuscular steroid injectors.
Dawson's discovery prompted him to establish a specialist clinic that today treats around 600 anabolic steroid users a year and has established him as the leading medical expert on the scale of steroid use in the UK.
Dawson has witnessed an explosion in the use of steroids and, more worryingly, a change in the profile of users. Where once steroids were the preserve of elite athletes and the body building clientele of "hardcore" muscle gyms, the doctor is seeing increasing numbers of young men, even adolescents, turning to steroids for no other reason than Friday night vanity.
"The youngest person I have treated is 15. We have realized that this isn't a small, isolated problem. It's an international problem for the youth of today," he said. "There will be people out tonight in Newcastle [northern England] who are using steroids, not because they want to run faster or jump further, but just because they want to look good."
Despite the boom in steroid use and the potential dangers involved, less is known about the scale of the problem than with any other controlled drugs. While steroids are banned under the same Misuse of Drugs act that controls the supply of cannabis and cocaine, users do not consider themselves standard drug takers because of the association with fitness and nutrition.
Experts say a mythology has grown up around anabolic steroids, a myth fed by the importance that sports' governing bodies attach to testing for them. In evidence they cite the increased sales of steroids and supplements that usually follow the exposure of high-profile athletes who test positive for drugs, such as the British sprinter Dwain Chambers.
The phenomenon was most obvious when elite athletes began testing positive for nandrolone, a substance that boosts endurance.
"The stuff literally flies off the shelves [after a positive test]" said a warehouseman at one leading nutritional product manufacturer. "The public seems to believe that if it's good enough for the stars, then it's good enough for them."
Certainly there is nothing good about testicular atrophy, baldness and breast growth -- some of the side-effects commonly associated with steroid use.
Neither are blood disorders or abscesses caused by dirty needles and drugs manufactured in unhygienic environments, yet the rise in steroid use is undeniable.
No nationwide study of drug use has been undertaken but the London-based Guardian newspaper has found a growing body of evidence that points to a burgeoning market for illegal anabolic steroids in the UK, and a disturbing shift in the demographic spread of the people taking them.
A study by the University of Glamorgan, Wales, has identified steroid use by children as young as 14 in south Wales, and found that use of the drugs spanned a wide social spectrum including teachers, police officers and office workers.
Britain's Home Office estimates that as many as 42,000 people used the drugs in 2001 to 2002. Police and customs seized more than 70kg of anabolic steroids during the same period.