Best Supplements for Reduced Diastolic Blood Pressure
Ranked by research evidence. Compare 103 supplements across 156 papers from the biomedical literature, with effect direction, evidence strength, and dose range for each.
Top picks by evidence
- Moderate evidence4 studies
Across 4 studies (all meta-analyses or observational), black cumin (Nigella sativa) supplementation consistently showed small beneficial effects on diastolic blood pressure, with all findings statistically significant. The most-studied dose range is 200–4600 mg/day, and effects were observed in metabolic disease patients and postmenopausal women with hypertension. Median study duration was 32 days (about 4.6 weeks), so benefits appear within a few weeks.
Dose: 200-4600 mg/day - Moderate evidence4 studies
Across 4 studies, all reported beneficial effects of red grape extract (primarily grape seed extract) on reducing diastolic blood pressure, with predominantly small effect sizes. The median study duration was 34 days (range: 7–60 days), and the most studied dose was 520 mg/day in one trial, though dosing varied across studies. Evidence primarily comes from hypertensive or metabolic syndrome populations.
Dose: 520 mg/day (single dose reported; other studies did not specify dose) - Moderate evidence4 studies
Across 4 studies, 3 reported beneficial effects (small to moderate reductions) on diastolic blood pressure, while 1 high-quality meta-analysis found a neutral effect. Predominant effect size among beneficial studies is moderate. Studies primarily focused on clinical populations with metabolic or cardiovascular conditions.
103 supplements
- ModerateBlack CuminAcross 4 studies (all meta-analyses or observational), black cumin (Nigella sativa) supplementation consistently showed small beneficial effects on diastolic blood pressure, with all findings statistically significant. The most-studied dose range is 200–4600 mg/day, and effects were observed in metabolic disease patients and postmenopausal women with hypertension. Median study duration was 32 days (about 4.6 weeks), so benefits appear within a few weeks. · Dose: 200-4600 mg/day4 beneficial4 studies
- ModerateRed GrapeAcross 4 studies, all reported beneficial effects of red grape extract (primarily grape seed extract) on reducing diastolic blood pressure, with predominantly small effect sizes. The median study duration was 34 days (range: 7–60 days), and the most studied dose was 520 mg/day in one trial, though dosing varied across studies. Evidence primarily comes from hypertensive or metabolic syndrome populations. · Dose: 520 mg/day (single dose reported; other studies did not specify dose)4 beneficial4 studies
- ModerateflaxseedAcross 4 studies, 3 reported beneficial effects (small to moderate reductions) on diastolic blood pressure, while 1 high-quality meta-analysis found a neutral effect. Predominant effect size among beneficial studies is moderate. Studies primarily focused on clinical populations with metabolic or cardiovascular conditions.3 beneficial1 neutral4 studies
- ModerateMoringaAcross 3 studies, all reported statistically significant beneficial effects of Moringa on diastolic blood pressure. One meta-analysis found a moderate reduction (SMD -0.41, 95% CI -0.75 to -0.07), while two systematic reviews reported larger reductions (mean difference -6.82 to -7.32 mmHg). The evidence base is small and overwhelmingly positive, which may reflect publication bias; no consistent dose or form data were reported.3 beneficial3 studies
- ModerateSpirulinaAcross all 3 studies, spirulina supplementation was consistently associated with beneficial moderate-sized reductions in diastolic blood pressure. Two meta-analyses reported reductions of approximately -2.84 mmHg and -3.09 mmHg, and a systematic review reported a moderate effect size (g = -0.73). The most studied population was overweight and obese adults, though other meta-analyses included general healthy adults over 18 years.3 beneficial3 studies
- LowL-CitrullineAcross 4 studies, 2 reported beneficial effects on diastolic blood pressure (one moderate-sized, one small), while 2 reported neutral effects. Overall, the evidence suggests a potential small reduction in DBP, predominantly observed in older adults, but the findings are mixed and not consistently statistically significant. Most studies used doses of 6–10 g/day over 2–8 weeks.2 beneficial2 neutral4 studies
- ModerateBeetrootAcross 3 studies, 2 reported beneficial effects on diastolic blood pressure, with effect sizes ranging from small to moderate. One meta-analysis found a small but significant reduction per mmol increase in nitrate intake, while a smaller RCT observed a moderate reduction with beetroot juice. The evidence is based on a small number of studies with varied populations, including clinical and healthy adult groups.2 beneficial1 neutral3 studies
- LowLemon BalmAcross 3 studies, 2 reported beneficial effects of lemon balm on reducing diastolic blood pressure, with moderate to large effect sizes, while 1 meta-analysis found a neutral, non-significant effect. The two positive RCTs studied stage 1 hypertensive patients at doses of 10 mL/day (liquid extract) and 400 mg/day (powder), with effects observed after 28 days. The evidence is limited in volume and mixed in outcome, with beneficial effects seen in individual RCTs but not confirmed in the sole meta-analysis. · Dose: 400 mg/day (powder) or 10 mL/day (liquid extract)2 beneficial1 neutral3 studies
- LowVitamin CAcross 3 studies, 2 reported beneficial effects of vitamin C on diastolic blood pressure, with effect sizes ranging from small to large. The median study duration was 40 days, suggesting effects may emerge over several weeks. The most prominent beneficial effect was observed in a meta-analysis of adults with diabetes, while evidence in young healthy adults was neutral.2 beneficial1 neutral3 studies
- Lowchia seedAcross 3 studies, 2 reported beneficial effects on diastolic blood pressure, with effect sizes ranging from moderate to large, while 1 study found no effect. The median study duration was 70 days. Doses of 30–50 g/day were studied, but results were inconsistent across doses and populations.2 beneficial1 neutral3 studies
- LowFlaxAcross 3 studies, 1 reported a moderate beneficial effect of flaxseed oil on diastolic blood pressure (DBP) in adults with metabolic syndrome, while 2 meta-analyses found no significant effect in broader populations. The beneficial study used 25 mL/day of flaxseed oil for 49 days, but the aggregate evidence is predominantly neutral with small effect sizes. Median study duration was 49 days, though only 1 study reported duration. · Dose: 25 mL/day (from the single beneficial study)1 beneficial2 neutral3 studies
- LowblueberryAcross 3 studies, 1 reported a small beneficial effect on reducing diastolic blood pressure, while 2 found neutral effects. The beneficial finding was statistically significant, but the average reduction was small (−2.20 mm Hg). The evidence is drawn from meta-analyses and a systematic review, mostly in healthy adults, with dose and duration not consistently reported.1 beneficial2 neutral3 studies
- LowFenugreek SeedAcross 3 studies, 1 reported a beneficial small effect of fenugreek seed supplementation on diastolic blood pressure, while 2 found neutral effects. The only statistically significant finding (p < 0.001) came from a small RCT in Alzheimer's patients using 5 cc of fenugreek seed extract over 120 days, while a meta-analysis and another RCT found no significant reduction. Evidence is limited and mixed, with no clear convergence on dose or population, and the median study duration was 88 days across two studies.1 beneficial2 neutral3 studies
- LowavocadoAcross 3 studies, 1 reported a small beneficial effect on diastolic blood pressure, while 2 found neutral effects. The predominant effect size is small. The most studied dose is 1 avocado daily, and the populations include adults with abdominal obesity or elevated triglycerides. Effects were observed in a 6-month trial, but a shorter 21-day trial showed no significant change. · Dose: 1 avocado per day (approximately 180 g or 300 kcal)1 beneficial2 neutral3 studies
- Very lowL-ArginineAcross 3 studies, 1 reported a beneficial moderate-sized effect on diastolic blood pressure, while 2 reported neutral findings of small magnitude. The single beneficial effect was observed in a meta-analysis of middle-aged and elderly individuals receiving combined L-citrulline and L-arginine supplementation. Evidence is too limited to identify a consistent dose range or study duration.1 beneficial2 neutral3 studies