Will taking ashwagandha cause problems when taking hypertension meds?

Doctor supervision! If you take any over the counter supplements and are taking prescription medications, you should do so with your doctor's knowledge and supervision. Ashwaghanda can raise your thyroid levels, especially if you are taking thyroid medication. Some otc supplements can have devastating side effects when taken with prescription meds, so only do with your doctor's supervision!
No. Ashwagandha is likely to benefit those taking hypertensive meds. There are no known interactions between ashwagandha and hypertensive meds. Ashwagandha is considered one of the best herbal treatments for hypertension in ayurveda, though I am unaware of any studies proving this. However, it is well known for its stress-reducing effects, which is likely to help those with hypertension.