In general, always consult your healthcare practitioner when adding new herbs alongside existing medications. Though there are not many contraindications in current literature, Ashwagandha can boost thyroid levels, so take care if already on an existing thyroid stimulating or hormonal replacement therapy. Ashwagandha is also known to enhance the effectiveness of opiates and certain sedatives such as benzodiazepines, so please keep that in mind when adding it into your regimen.