Supplements, such as magnesium, fish oil, and potassium may help lower blood pressure.Credit: Anastasiia Zabolotna / Getty ImagesKey TakeawaysMultiple experts recommend magnesium because research suggests it may help relax blood vessels and modestly lower blood pressure.Potassium also supports healthy blood pressure, while probiotics and omega-3s may benefit blood vessels and other cardiovascular risk factors.Treat supplements as an add-on, not …