A 2002 study by Kar, Panda and Bharti involving mice showed a 41% increase in production of the thyroid hormone T4 when given 200 mg of Bacopa extract per day. The thyroid hormone T3 was not stimulated. It should be noted that the administered dose in this study was very high for rats. The recommended daily dose for humans of 200-400 mg may not be sufficient to induce a similar effect (Kar A, Panda S, Bharti S. Relative efficacy of three medicinal plant extracts in the alteration of thyroid hormone concentrations in male mice. J Ethnopharmacol 2002;81:281-285).