Purple tea (Camellia sinensis var. assamica), native to Kenya, is rich in anthocyanins (the pigments that give it its distinctive purple color) as well as catechins and gallic acid. Its use for weight loss is relatively new and is primarily supported by preliminary scientific studies rather than longstanding traditional use.

A few small-scale animal and human studies have investigated purple tea extract’s effects on body weight and fat metabolism. The most frequently cited human trial is a randomized, double-blind, placebo-controlled study published in 2015 (Oyama et al., Food Science & Nutrition), which found that subjects taking purple tea extract for 4 weeks experienced a small but statistically significant reduction in body weight and body fat compared to placebo. The proposed mechanisms include inhibition of lipid absorption and enhancement of fat metabolism, attributed to the unique combination of polyphenols, including GHG (1,2-di-galloyl-4,6-hexahydroxydiphenoyl-β-D-glucose), which is present in higher amounts in purple tea.

However, the existing studies are limited in size and duration, and independent replication is lacking. The evidence is stronger than anecdotal or traditional claims but does not yet rise to the level of robust, high-quality clinical evidence. Therefore, while there is some scientific validation, it is still preliminary, justifying a moderate-low evidence score.