Withania somnifera
Withania somnifera, also known as ashwagandha, is a root extract used in traditional Ayurvedic practice and sold as a herbal supplement. Its withanolide constituents are thought to act on stress-response signalling, including the hypothalamic-pituitary-adrenal axis. It is taken in the context of anxiety and sleep support.
The extract is taken with food, which reduces the stomach upset some people notice. It can raise thyroid hormone output, so it may add to the effect of levothyroxine and shift TSH and free T4, and it is used cautiously by anyone with thyroid disease. Rare cases of liver injury have been reported, making ALT worth watching, and testosterone can also move; it is not used during pregnancy.
Yellowing of the skin or eyes, dark urine, persistent nausea or right-sided abdominal pain suggest liver trouble and mean seeing a doctor without delay. Palpitations, unexplained weight loss, heat intolerance or agitation, particularly alongside thyroid medication, also warrant medical review.
Reference information, not medical advice. Discuss any change with your doctor.