I have looked at scientific evidence supporting the most popular weight loss herbal supplements mentioned in Ayurveda and Traditional Chinese Medicine. The summary of my research on Ayurveda supplements is presented below:
A herbal combination containing the following herbs – Cyperus rotundus, Saussurea lappa, Curcuma longa, Berberis aristata, Acorus calamus, Aconitum heterophyllum, Picorrhiza kursoa, Plumbago zeylanica, Holoptelea integrifolia, and Iris ensata is a formulation prescribed to control obesity. (Kumar and Bhandari 2015) A small trial with 70 obese individuals claims a reduction in obesity. (Paranjpe et al., 1990)
Ayurveda anti-obesity formulation – lekhana basti contains Terminalia bellerica, Terminalia chebula, Embilica officinalis, Cyperus rotundus, Holoptelea integrifolia, Berberis aristata, Curcuma longa, Embelia ribes, mustard oil, honey, cows urine, a formulation made from barley (Hordeum vulgare), and rock salt.
A trial on 40 obese individuals prescribed Lekhaniya vati and Lekhana basti formulations for 30 days. Better results accrue when the formulations are used in combination than singularly. (Payal et al., 2017)
The scale of both these trials is relatively small. It is difficult to conclude the effectiveness or otherwise of a formulation based on a single experiment. Most formulations must undergo multiple clinical trials to finally culminate into a post-release user trial before receiving a final regulatory nod to sell a formulation to consumers.