Nearly 85 per cent of people interviewed in a survey say the sale of slimming pills should be placed under stricter controls. The telephone poll of 635 people conducted by the Democratic Party showed 69.9 per cent said adverts for the slimming products were exaggerated and unreliable. Also, 72 per cent believed the products were harmful to health. However, 34 respondents, or 5.4 per cent, said they took diet pills. Among them, 22 said they had felt unwell after taking the products. The party said health officials should tighten control over the products. 'The sale of diet pills seems to be in a legal vacuum as those products contain only Chinese herbs but no Western medicine - so they are not restricted under the Pharmacy and Poison Ordinance,' legislator Fred Li Wah-ming said.