Is it safe to take losartan and melatonin together?

While there is no known drug-drug interaction between losartan and melatonin, individual side effects still apply. Take meds as prescribed, let your doc know if using OTC meds or supplements.

Should be relatively safe as losartan is for your blood pressure control, and the hypertension would not be influenced by the melatonin. But be diligent and check the additives included within your OTC melatonin, as there could be some items which may cause issue.