US children as young as 11 are taking illegal steroids in a bid to achieve their dream of sporting or Olympic glory, senators have been told.
Steroids are used to enhance muscle size
Head of the US anti-doping agency, Terry Madden, told a Senate committee people needed to be warned that steroid use was dangerous to children's health.
The committee was told that more than 500,000 high school-age children were estimated to be using steroids.
It comes as several athletes are facing an inquiry over alleged steroid abuse.
Senator Charles Grassley said it was estimated some five million people annually used the drugs "to improve athletic performance, appearance and self-image".
Of that, 175,000 are estimated to be high school girls and 350,000 are high school boys, he said.
'Driven to suicide'
"Those same studies have shown that some users start even younger, first using steroids while they are in middle school," said Mr Grassley, presiding at the Senate Caucus on International Narcotics Control.
One father told how his 16-year-old son took steroids after he was told to gain 20 pounds if he wanted to be a starting pitcher in baseball. After he stopped taking the drugs, he suffered a depression that drove him to suicide.
The hearing was told by Mr Madden that the availability of steroid-based products was "currently effectively unregulated".
He described it as a "health crisis that affects not just Olympic athletes, but every American teenager who dreams of becoming a professional or Olympic athlete, and every consumer who takes one of these products without being informed of the risks".
Mr Madden also called for uniform standards for testing
US amateur and pro athletes across all sports.
He said insufficient doping testing in some premier pro sports leagues had given a perception to other countries that US athletes routinely used illegal performance-enhancing substances.