Medical specialists are war ning members of the public to be aware of unscrupulous shopkeepers selling herbal medicines and preparations that claim to provide a cure for male impotence. Several people have reportedly been taken to hospital or been rendered impotent after taking herbal medicines. “Many middle-aged men come to us asking for types of herbal sexual stimulants they've seen in advertisements in newspapers or on television,” said Omaer, Ali, Muhammed and Saeed, all four of whom run herbal shops in Tabuk. They refute accusations that shopkeepers make extravagant claims for their products – like saying they can cure impotence in men of any age with herbal medicines made of “magic-like” ingredients – or that they illegally adulterate products. “We strictly abide by health ministry instructions and guidelines which prevent the sale or promotion of herbal medicines mixed with honey, water or oil,” they said. Dr. Ibrahim Muhammed Waheeb, a cardiology specialist, said that most herbal medicines include harmful components. Dr. Waheeb said that pharmacists specialized in clinical pharmacy working in drug factories usually extract harmful components from herbs and that resulting products are licensed and approved by authorities such the Food and Drug Agency in the United States and other countries. He said that doctors specialized in alternative medicine are best qualified to prescribe herbal medicines because they know the contents. “Some people suffering from illnesses that modern medicine hasn't been able to treat resort to herbalists who too often mislead them and exploit them,” Waheeb said. Dr. Dia Mubarak, a specialist in dermatology and sexual diseases, said that around half of all cases of impotence are purely psychological. “Some herbal shops know their customers' desire for stimulants and exploit them to the full,” he said. “In many cases these medicines worsen their condition leading to complications that endanger lives noting that some of the contents can destroy liver cells and eventually cause liver and renal failure,” he added.