Reports have been splashed over the gossip websites that pop superstar Britney Spears used diet pills as a quick fix for her weight problems during her multi-million pound Circus tour.  Website Betty Confidential has claimed that Spears was buying diet pills without prescription, washed down with the caffeine drink Red Bull, before going on stage.

The site's source told them that "Britney was definitely trying to get high by taking too many diet pills and energy drinks." He added, "Britney uses green-tea supplements, [Lab 88’s herbal ephedra-free] Metabo Speed XXX, Dexatrim and apple cider vinegar to control her weight and energy levels. She also pours those 5-Hour energy drinks into her Red Bulls."

The report shed a frightening light on the lengths that the star, who over the past couple of years has been the target of poisonous criticism of her weight,  is willing to go to to retain her famous flat stomach. Dogged by a series of scandals relating to her drinking, drug use and relationships with men, it had been hoped that her recent tour and successful album marked a changing point in her previously chaotic life.

However the new reports suggest that Spears may still be struggling with her demons, particularly relating to her weight. It is likely that in Hollywood, she is not alone - it is widely talked about behind closed doors that many celebrities rely on slimming pills and buy diet pills without prescription to help them keep their figures.

In America  consumers can buy a variety of diet pills without prescription, from the lower-dose version of Xenical, Alli, to any number of herbal slimming pills. While the slimming pills Alli have been extensively tested and is believed to be safe and effective, there are serious questions as to whether most of the other diet pills without prescription actually work.

Betty Confidential said that the stress of touring might be to blame for Spear's resorting to diet pills to help her retain her already very thin figure, saying that the stress of the constant travelling and touring was beginning to impact on her physically. Their source said, "Since she has been so active, she's fallen back to some of her old fast food habits, but her friends and family are trying to keep her from overindulging."

Recently, actress Natasha Henstridge said that she too had been reliant on diet pills, which as she did not need them - Alli is supposed to only be used by the dangerously obese - had permanently affected her metabolism.