Growing numbers of middle-aged men are turning to anabolic steroids to make themselves look and feel more youthful and boost their sexual performance, experts say.

People who work with users have raised concern about a new trend among men in their 40s and 50s, and some even in their 60s and 70s, who are taking the drug to boost energy levels and fight some of the effects of ageing, such as weight gain and a lower libido. Steroids can cause a range of health problems such as heart disease and blood clots.

“We have come across a lot of older men using. It’s almost like hormone replacement therapy [used to relieve symptoms of the menopause] for females. Steroids can help you lose body fat as well,” said Julien Baker, an applied physiology professor at the University of the West of Scotland.

“It is a major problem, but the evidence isn’t there about what the long-term impact is yet. We are not sure what these drugs are doing to you at that age, but everyone perceives it as safe.”

As men get older their testosterone levels drop, which can sometimes lead to a reduced sex drive, weight gain and muscle reduction. Baker says men get information from magazines and online about the drug, which mimics the effects of testosterone and boosts muscle growth, though some are also prescribed it.

Joseph Kean, visiting research fellow at Liverpool John Moores University, said while over-50s still accounted for only a small proportion of the image- and performance-enhancing drugs population, their numbers have doubled over the past five years. He estimated there were between 15,000 and 30,000 over-40s using in the UK.

“Guys are saying they just want to stand a bit taller and feel they can stand alongside the younger generation who are much more aware of how they look,” Kean said. He explained that older men typically used smaller amounts of the drug less frequently than their younger counterparts.

A typical steroid cycle can be about three months, starting with less and building up before tapering off. “At its peak you could be taking steroids daily and injecting around four times a week,” said Kean. “Older guys tend to take less, but for much longer – one injection every seven to 10 days and sometimes almost consistently.”

The Juice Clinic in Sheffield, a service for people using steroids and image-enhancing drugs, has noted an increase in older men asking for help.

“Steroid use for older men is often about the youthful effects, and about body image and energy levels,” said Sid Wiffen, the clinic’s team leader. “I hear talk of men feeling more pressure now to look good, so they are more likely to go to the gym and dress well.

“It can be dangerous and it does worry me. Lots of people we see are keen to make an informed decision about their steroid use, but some get information elsewhere and it’s not always good.” Once users begin to decrease or discontinue use of steroids, withdrawal symptoms such as low mood and anxiety can occur.

Commentators say the growing popularity of such drugs could be the result of societal changes, with people living longer and expecting more from life.

“With an ageing population there are now more key points in people’s lives when they are concerned about appearance,” said Jim McVeigh, an expert on steroid use at Liverpool John Moores University.

“For men who get to a certain age where they are unable to maintain a particular physique naturally, you can see how they would be tempted to try other means to get a body they maybe found easier to achieve 15-20 years ago. Wanting to look good is no longer just the domain of the young.”

But a former user, who asked to remain anonymous, disagreed that there was any more pressure on midlife men now than before. He started taking the drug at 41 and said: “Steroids will be attractive to any middle-aged man who can see their youth disappearing and want to fight the inherent vulnerabilities of middle age.”

The findings coincide with reports of increasing anabolic steroid use, with a particular focus on younger men. Last year people who worked with steroid users estimated that the real numbers of those taking the drug annually was far higher than the 60,000 people quoted in the Crime Survey for England and Wales.

The drugs, officially known as anabolic-androgenic steroids, were first developed for medical use. While they remain a class C prohibited drug, experts say people are finding it easy to get the drugs online or in gyms. They come in tablet form, although they are more commonly injected into muscles.Baker said while there could be some benefits for older men under a proper prescription regime, there were risks attached to self-medication and buying the products online. “Introducing something your body stopped producing naturally may lead to repercussions or have health implications,” he said. “There’s not enough research out there to look at that. Someone taking steroids at 50 – it’s not clear what might happen to them in the future.”

‘Getting older gets put on hold for a while’

The Guardian spoke to a 53-year-old steroid user, who asked to remain anonymous, about why he chose to take the drug.

“I am a normal 53-year old guy and I am a non-smoker who eats well and looks after himself. I go to the gym three or four times a week. I drink some weekends and lead an active social life. I have also been taking steroids for the last three years.

“I was apprehensive when I started. I am not a bodybuilder and have never wanted to be one. I got the drug at my gym. I wanted to look healthy and have a nice physique, not rippling muscles but just a bit more definition. I never took steroids when I was younger. Now I have a small dosage once a week and it’s made me feel fantastic. My testosterone levels and other blood levels are normal. I know this because I have my blood checked regularly at a local clinic for users.

“Not only have I got the extra muscle mass I wanted, but the drug has also made me feel good about myself and made me sleep better. It has given me an appetite for life and a better sex drive. No one knows I’m on steroids except my partner, who is fine with it.

“I am not talking about taking massive amounts. I don’t have a massive 60-inch chest. I am a normal guy who looks well for his age. I have a slim waist, not a big belly, and train a little bit.

“I don’t want to look like younger guys. I am taking the drugs for me, to look good and feel happy. Steroids make you feel more youthful, and in a corny kind of way it is like drinking a feelgood elixir. All the characteristics of getting older, such as feeling tired etc, get put on hold for a while.

“When you come off it, in my experience, your body goes back to its normal cycle again eventually. Then, I am tired and all the normal characteristics associated with someone over 50 come back.

“Anything in excess is bad for you, but if taken in moderation then it’s not a problem. It’s like having alcohol, it’s all down to drinking and doing things in moderation. Steroids should fall into that bracket.

“I suppose I do worry about the long-term impact of steroids on my body. But I also worry about additives in foods and the effect of using mobile phones on my brain. The list is endless. Irresponsible use and abuse is always the main problem.”