A study in the US shows gay and bisexual teenagers are six times more likely to use steroids compared to their heterosexual peers.

Reasons for the differences are unclear, but the authors say it’s possible gay teens feel more pressure to achieve a bulked-up ‘ideal’ male physique, or that they think muscle-building steroids will help them fend off bullies.

“It’s a bit sad that we saw such a large health disparity,” said co-author Aaron Blashill, a psychologist and scientist with the Fenway Institute.

“Given the dramatic disparity … it would seem that this is a population in which greater attention is needed,” the authors added.

Overall, 21% of gay or bisexual boys admitted they had used steroids, compared to 4% of straight boys. The difference was similar among those who reported moderate use – taking steroid pills or injections up to 40 times: 8% of gay or bi teens reported that amount, versus less than 2% of straight boys.

The heaviest use – 40 or more times – was reported by 4% of gays or bi boys, compared with less than 1% of straight teens.

The nationally representative study is an analysis of US government surveys from 2005 and 2007. It involved 17,250 teen boys aged 16 on average; almost 4% – 635 boys – were gay or bisexual

Steroids include synthetic versions of the male hormone testosterone.

Users take them to promote muscle growth, strength and endurance. Side effects can include heart and liver problems, high blood pressure, acne and aggressive behaviour.

With their still-maturing bodies, teens face a heightened risk for problems that may be permanent, the US Food and Drug Administration warns.

Steroids are legally available only by prescription.

Outside of Steroid use, resistance training (using weights) should be closely monitored for younger people, as their skeletons and bones are still developing.