The safety and efficacy of a dietary herbal supplement and gallic acid for weight loss.

The objective of this study was to test the safety and efficacy of NT, a dietary herbal supplement made from rhubarb, ginger, astragulus, red sage, and turmeric, combined with gallic acid (GA) to reduce food intake and cause weight loss. A total of 105 healthy subjects, 18-60 years old with a body mass index of 25-35 kg/m(2) and on no chronic medication, were randomized to a 300 mg/1.2 g NT-GA combination, a 600 mg/2.4 g NT-GA combination, or placebo in three divided doses daily for 24 weeks. Food intake was measured at baseline and 2 weeks, and safety parameters were followed regularly. Pharmacokinetic studies of a 200 mg/800 g NT-GA combination and 800 mg GA alone were performed with and without food. There was no dose-related weight loss or reduction in food intake at the 8-week analysis, and the study was terminated early. Pharmacokinetic studies showed plasma levels of GA did not increase above 10 microM and were not dose-related. The NT-GA at all concentrations was well tolerated, but was ineffective in causing weight loss or in suppressing food intake. Pharmacokinetics suggested that GA plasma levels were limited by oral absorption, and may be the reason for lack of efficacy.