Benefits
Appetite and weight gain in a rat study (animal work)
In rats (6 per group) given a dry leaf and stem extract by tube for 40 days, the lowest dose (500 mg/kg) reduced weight gain and calorie intake on both a standard and a junk-food diet, while the two higher doses mostly did not. That dose equals roughly 5 to 6 g a day for a 70 kg adult, far above what products supply.
Mouse studies of food intake and weight gain (animal work)
Mouse results disagree. In one study, 300 mg/kg of extract reduced eating in mice over a short course. In another, 2,000 mg/kg daily for 15 days did not reduce weight gain or food eaten compared with untreated mice, and those authors concluded the extract was not effective. No mouse result has been checked in people.
Caffeine measured in one raw-material sample
In a Brazilian lab analysis, a bulk sample sold as Cordia ecalyculata contained about 4.3% caffeine by weight, more than the green tea and guarana samples tested alongside it, while a sample labeled Cordia salicifolia had none detectable. Two samples of a pharmacy formula labeled 300 mg of the herb contained only about 2 to 4 mg of caffeine per dose.
Brazilian nutrition guidance on weight-loss herbs
A position statement from the nutrition department of the Brazilian obesity society (ABESO) lists Cordia ecalyculata among plant products that do not contribute to weight loss, and makes no recommendation to use herbal products for that purpose. For this herb the statement cites only lab and mouse papers, not human trials.
Yerba mate, guarana and damiana blend trials do not include it
The best-known South American herbal weight blend, sold as YGD, contains yerba mate, guarana and damiana and no cha de bugre. In a small trial it slowed stomach emptying and was followed by more weight loss than placebo over 45 days. None of that can be credited to cha de bugre, which was not in the capsules.
Mechanism of action
Caffeine content varies from none to substantial
Some cha de bugre material contains caffeine, a stimulant, which may be part of why it is sold for appetite and energy. But measured amounts ranged from undetectable to about 4% by weight between samples, and no study has tested whether the caffeine in cha de bugre products changes appetite in people.
Traditional diuretic use: water weight is not body fat
Cha de bugre is used in Brazil as a diuretic as well as an appetite suppressant. Any diuretic effect would shift body water, not body fat, and a rat study summarized in the research literature found no diuretic or appetite effect from the powdered leaf at 20 mg/kg.
Other plant compounds are poorly characterized
A leaf extract analyzed in the lab was rich in the sesquiterpene spathulenol, which showed only very weak activity against stomach bacteria in a test tube. Allantoin and tannins are listed on supplier phytochemical labels, but no published analysis cited here measured allantoin in the leaf, and no compound has been linked to an effect in people.
Clinical trials
Animal study of a commercial dry leaf and stem extract given by tube at 500, 1,000 or 2,000 mg/kg for 40 days (weight-gain model) or 30 days (in rats first fed the diets for 40 days), with blood chemistry and DNA damage tests. (Nunes et al. 2022, Acta Sci Pol Technol Aliment)
96 male Wistar rats, 6 per group, fed a standard diet or a high-calorie cafeteria diet. No people were studied.
Only the lowest dose (500 mg/kg) clearly reduced weight gain and weekly calorie intake; the higher doses mostly did not. In the 30-day phase, rats on the cafeteria diet lost weight on all doses, most with 500 mg/kg, though the authors noted the diet-fed rats showed little sign of true obesity. Serum albumin rose at several doses, and the highest dose increased DNA damage in blood cells in one group. Groups were very small and the doses far exceed product amounts.
Mouse study of oral Cordia ecalyculata at 150, 300 and 500 mg/kg, alone or combined with Spirulina maxima, plus test-tube micronucleus and comet assays on human blood cells. (Araldi et al. 2014, Genet Mol Res)
Swiss mice of both sexes, and human peripheral blood cells in the lab. No people took the herb.
Cordia ecalyculata at 300 mg/kg, and the 500 mg/kg Cordia plus 250 mg/kg spirulina combination, reduced eating (an anorectic effect). The mutagenicity tests found no DNA-damaging activity. The authors described the herb as a candidate weight-reduction drug; that is a hypothesis from mouse data, not a human finding.
Mouse study of the genotoxic and cytotoxic effects of crude extracts of Cordia ecalyculata and Echinodorus grandiflorus, including a 15-day test of body weight and food intake. (da Silva et al. 2010, J Ethnopharmacol)
Swiss mice given the extract by mouth. No people were studied.
After 15 days at 2,000 mg/kg a day, the extract did not reduce body weight gain or food eaten compared with control mice (P > 0.05), and the authors concluded it was not effective for obesity. Micronucleated red cells rose significantly versus control, which the authors described as weak clastogenic activity while concluding that the extract was not cytotoxic or genotoxic.
Blend trial, not a cha de bugre trial: a gastric-emptying test plus placebo-controlled 10-day and 45-day weight studies of YGD capsules, with 12 months of uncontrolled follow-up. (Andersen et al. 2001, J Hum Nutr Diet)
7 healthy volunteers (gastric emptying), 44 overweight patients (10 days) and 47 overweight patients (45 days, double-blind) attending a primary health care center; 22 continued for 12 months.
YGD slowed stomach emptying (58 vs 38 minutes) and weight fell 5.1 kg vs 0.3 kg with placebo over 45 days; the 12-month phase had no control group and showed no further loss. The blend contains no Cordia, so this says nothing about cha de bugre; it is a small, older trial of a different product.