withania somnifera
2 interactions related to withania somnifera
caffeine + ashwagandha
Caffeine is a stimulant that raises alertness and cortisol; ashwagandha is an adaptogenic herb that, taken on its own, modestly lowers cortisol and perceived stress in human trials. People combine them hoping ashwagandha will take the edge off caffeine's jitters. That pairing is plausible but has not been tested directly in humans, so the 'calm focus' benefit remains theoretical rather than proven. The combination is generally well tolerated in healthy adults.
levothyroxine + ashwagandha
Ashwagandha (Withania somnifera) can lower TSH and raise T3 and T4, so it acts on your own thyroid axis on top of the levothyroxine you already take. A randomized trial showed this hormone shift in people with subclinical hypothyroidism, and separate case reports describe ashwagandha-related thyrotoxicosis and painless thyroiditis. Those case reports were not in people taking levothyroxine at the same time, so the additive-overreplacement scenario is plausible but not directly documented.