More must be done to help the rising tide of people who are injecting themselves with steroids, health experts have warned.
Reports suggest the number of people, including teenagers, who use steroids and other performance or image enhancing drugs is "rapidly increasing", the National Institute for Health and Care Excellence (Nice) said.
Outreach programmes should be set up in gyms to try to reach this group of drug users, Nice said.
In new guidance, the health authority said that needle and syringe programmes - which were set up in the 1980s and 1990s to stem the spread of HIV - should also make sure that these drug users have the sterile equipment they need to prevent the spread of blood-borne viruses.
Meanwhile, local health bodies need to increase the proportion of these drug users who are tested for HIV, hepatitis B and C and other viruses.
People who use these drugs do not see themselves as having a drug problem, a Nice spokesman said.
In fact, they see themselves as "fit and healthy" despite the fact that people who inject themselves with any type of drug are at a heightened risk of HIV and hepatitis.
Nice warned that anabolic steroid use is "relatively widespread" with an estimated 59,000 people aged 16 to 59 using the drug in England and Wales in the last year.
But Nice said these estimates are "conservative" and said that needle and syringe programmes have reported "rapidly increasing" numbers of steroid users attending their services.
David Rourke, harm reduction lead for Arundel Street Project - a needle and syringe programme in Sheffield, said: "We run a weekly clinic for steroid users but we have people coming through the door on a daily basis, with at least seven new clients a week. We know there are many more people out there who are not using needle and syringe programmes because this group of users do not see themselves as drug users. Traditionally they are more sexually active than users of heroin or crack, so there is more potential for the spread of infections through sex.
"This guideline gives front-line workers clear recommendations on how to support image and performance enhancing drug users. Up to now this has been a grey area; services around the country have been patchy to say the least.
"In Sheffield we are lucky to have a special programme for those who use steroids to access information and support but I know of some areas where there is nothing.
"People who inject steroids are potentially using them without the correct education or the correct equipment and this can lead to more and more people injecting unsafely, which can put not just their own life, but the lives of those around them, at risk.
"Those who use steroids should be able to get the same support as anyone else who injects drugs. This guideline will make sure that services across the country are at the high standard they should be."
Professor Mike Kelly, director of Nice's Centre for Public Health, added: "Needle and syringe programmes have been a huge success story in the UK, they are credited with helping stem the Aids epidemic in the '80s and '90s. However, we are now seeing a completely different group of people injecting drugs.
"They do not see themselves as 'drug addicts'; quite the contrary, they consider themselves to be fit and healthy people who take pride in their appearance.
"Since we last published our guideline on needle and syringe programmes in 2009, we've seen an increase in the use of image and performance enhancing drugs such as anabolic steroids. We've also heard anecdotal evidence that more teenagers are injecting these image and performance enhancing drugs too. We're updating our guideline to make sure all of these groups of people are considered in the planning and delivery of needle and syringe programmes."
Dr Fortune Ncube, head of the blood-borne virus section, at Public Health England's National Centre for Infectious Disease Surveillance and Control, added: "Anyone who injects drugs is at risk of HIV and other blood-borne viruses, regardless of the substance they inject.
"Our recent research suggests that levels of HIV and hepatitis infection among men using image and performance enhancing drugs have increased since the 1990s.
"We must maintain and strengthen public health interventions focused on reducing injection-related risk behaviours to prevent HIV and hepatitis infections in this group. This includes ensuring easy access for those who inject image and performance enhancing drugs to voluntary confidential testing services for HIV and hepatitis and vaccination against hepatitis B, as well as to appropriate sterile injecting equipment through needle and syringe programmes."
Mark Moody, director of operations at health and social care charity CRI (Crime Reduction Initiatives), said: "Needle exchanges help to prevent the spread of blood-borne viruses like HIV and hepatitis C by giving people who inject drugs clean equipment and advice. In the long term, it also provides an opportunity for us to engage with people with problematic substance misuse to create new pathways to recovery.
"Every contact at a needle exchange is a chance for us to support recovery and our staff work hard to address specific issues and refer people to further support. This new Nice guideline will ensure that our staff are using the most up-to-date evidence available in their work. We particularly welcome the recommendations to involve people who use services and local communities in developing needle exchange programmes, as well as tailoring services to meet local need."