Though ashwagandha appears to be safe overall, there is still a potential for adverse effects, including thyroid issues, liver toxicity, immune stimulation, and electrolyte imbalances. Although clinical studies have not shown an increased risk of adverse events, case reports raise concerns.[1] For example, case reports have suggested adverse effects such as rash, itching, or thyroid dysregulation may occur with ashwagandha use, but the same adverse events were not seen in a safety study with a larger sample size.[2][3][4][5][6]
Concerns have also been raised regarding the occurrence of liver toxicity with ashwagandha use, although this has not been observed in clinical safety trials. In two 2024 case reports, liver injury was recorded when ashwagandha capsules were taken at dosages up to 1,350 mg per day for durations ranging from 30 hours to 6 months.[7][8] In other reports, liver toxicity was usually reported within 2 to 12 weeks of ashwagandha use, and liver function returned to normal in all but one case following medical support and stopping ashwagandha.[9][10][11][12][13][14]
Additionally, ashwagandha may influence immune and hormonal systems, which could put specific populations at a greater risk. In one case report, a kidney transplant recipient developed organ rejection after using ashwagandha for two weeks.[15] In another case report, a patient with high blood pressure developed hyponatremia (low sodium in the blood) and adrenal insufficiency with abnormally low cortisol levels after taking a combination of supplements that included ashwagandha.[16][17]
Case studies suggest that ashwagandha could have serious side effects, though there are often minimal details on dosage or formulation. However, larger clinical studies, especially those with standardized formulations and dose regimens, indicate that milder adverse events (e.g., drowsiness or sedation) can still occur.[4][18][19][20] In a more recent systematic review and meta-analysis, the majority of randomized controlled trials reported no adverse events, but several reported effects such as diarrhea, nausea, abdominal pain, rashes, and abnormal liver or kidney function tests.[1] More research is needed to fully understand the risks associated with ashwagandha. However, it is crucial that individuals, especially with pre-existing conditions or who are taking other medications, consult with their healthcare professional before starting any supplement regimens.