Taking 10 grams of L-citrulline daily for four weeks lowers aortic systolic blood pressure by 4 mmHg in postmenopausal women with hypertension, without altering aortic stiffness, suggesting a direct effect on blood vessel tone.

Taking 10 grams of L-citrulline daily for four weeks leads to a measurable improvement in blood vessel function and a small reduction in blood pressure in women with high blood pressure who have gone through menopause.

Taking L-citrulline supplements every day for a few weeks might slightly lower your blood pressure—like a small drop that could help keep your heart healthier.

Taking at least 6 grams of L-citrulline every day might lower your bottom blood pressure number by about 3 points, but taking less than that doesn’t seem to do anything noticeable.

Taking 10 grams of L-citrulline daily for four weeks increases blood flow and vessel dilation in the forearms of hypertensive postmenopausal women during handgrip exercise.

Taking L-citrulline pills or getting it from watermelon might help lower your blood pressure a little—especially if you already have high blood pressure and take it for at least six weeks.