Best Supplements for Reduced Diastolic Blood Pressure
Ranked by research evidence. Compare 110 supplements across 179 papers from the biomedical literature, with effect direction, evidence strength, and dose range for each.
Top picks by evidence
- High evidence6 studies
Across 6 studies, 5 reported beneficial effects of red grape supplement on diastolic blood pressure, with effect sizes ranging from small to moderate. One study found no significant effect. The evidence, including meta-analyses and RCTs, indicates a small reduction in DBP, with the most notable effects seen in populations with hypertension or metabolic syndrome. Median study duration was 34 days, suggesting short-term benefits.
Dose: 520 mg/day (from one RCT) - High evidence5 studies
Across 5 studies, all reported beneficial effects of black cumin (Nigella sativa) supplementation on diastolic blood pressure, with effect sizes ranging from small to large. The median study duration was 56 days (8 weeks), suggesting effects typically observed at 8 weeks. The evidence primarily comes from meta-analyses and RCTs in clinical populations with metabolic diseases or hypertension.
- Moderate evidence4 studies
Across 4 studies, 3 reported beneficial effects on diastolic blood pressure, with effect sizes predominantly small. The most robust study, a meta-analysis of 821 participants, showed a moderate reduction (MD -3.42 mmHg), while another meta-analysis found a small significant reduction (WMD -1.09 mmHg); one meta-analysis reported a neutral effect. Median study duration was 90 days, and evidence applies to healthy adults or those at high risk of cardiovascular disease.
110 supplements
- HighRed GrapeAcross 6 studies, 5 reported beneficial effects of red grape supplement on diastolic blood pressure, with effect sizes ranging from small to moderate. One study found no significant effect. The evidence, including meta-analyses and RCTs, indicates a small reduction in DBP, with the most notable effects seen in populations with hypertension or metabolic syndrome. Median study duration was 34 days, suggesting short-term benefits. · Dose: 520 mg/day (from one RCT)5 beneficial1 neutral6 studies
- HighBlack CuminAcross 5 studies, all reported beneficial effects of black cumin (Nigella sativa) supplementation on diastolic blood pressure, with effect sizes ranging from small to large. The median study duration was 56 days (8 weeks), suggesting effects typically observed at 8 weeks. The evidence primarily comes from meta-analyses and RCTs in clinical populations with metabolic diseases or hypertension.5 beneficial5 studies
- LowL-CitrullineAcross 6 studies, 3 reported beneficial effects on diastolic blood pressure (with mixed small-to-moderate effect sizes), while 3 found no significant effect. The most studied dose range was 6–10 g/day, and effects were observed in older adults and clinical populations. Median study duration was 28 days, indicating short-term use. · Dose: 6-10 g/day3 beneficial3 neutral6 studies
- Moderategreen teaAcross 4 studies, 3 reported beneficial effects on diastolic blood pressure, with effect sizes predominantly small. The most robust study, a meta-analysis of 821 participants, showed a moderate reduction (MD -3.42 mmHg), while another meta-analysis found a small significant reduction (WMD -1.09 mmHg); one meta-analysis reported a neutral effect. Median study duration was 90 days, and evidence applies to healthy adults or those at high risk of cardiovascular disease.3 beneficial1 neutral4 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
- ModerateSpirulinaAcross 3 studies, all 3 reported beneficial moderate-sized effects of spirulina supplementation on reducing diastolic blood pressure. The evidence consistently shows a statistically significant reduction, with meta-analyses reporting a weighted mean difference of approximately -2.84 to -3.09 mmHg. Studies primarily included overweight and obese adults or general adults over 18 years, though dose ranges and study durations were not consistently reported.3 beneficial3 studies
- ModerateMoringaAcross 3 studies, all three reported beneficial effects on diastolic blood pressure, with effect sizes ranging from moderate to large. The highest-quality evidence, a meta-analysis of randomized controlled trials, found a moderate reduction (SMD -0.41, 95% CI -0.75 to -0.07). Two systematic reviews reported larger reductions (mean difference -6.82 to -7.32 mmHg). Study durations were not consistently reported, and no specific dose or form was identified.3 beneficial3 studies
- LowL-ArginineAcross 4 studies, 2 reported beneficial effects of L-arginine (alone or combined with L-citrulline) on diastolic blood pressure, while 2 found neutral results. The predominant effect size among beneficial studies was moderate, though the evidence base is small. Most studies did not consistently report dose or duration, but the strongest evidence comes from a 2025 meta-analysis in middle-aged and elderly individuals showing a moderate reduction of -4.86 mmHg with combined L-citrulline and L-arginine supplementation.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
- 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
- LowHibiscusAcross 3 studies, 2 reported beneficial effects on diastolic blood pressure, with effect sizes ranging from small to moderate (mixed). The most recent and largest meta-analysis (2025, n=1797) found moderate reductions in DBP, particularly in individuals over 50 years and in trials lasting at least 4 weeks. The median study duration was 28 days. Evidence is limited to a small number of studies, and one high-quality meta-analysis (2022) found no significant overall effect in patients with hypertension and metabolic syndrome, suggesting population-specific responses.2 beneficial1 neutral3 studies
- LowVitamin CAcross 3 studies, 2 reported beneficial effects of vitamin C on reducing diastolic blood pressure, with effect sizes ranging from small to large. The median study duration was 40 days, and the most-studied population was adults, including specific subgroups such as patients with diabetes and heat-exposed workers. Evidence is limited by the small number of studies and mixed findings, including one neutral result.2 beneficial1 neutral3 studies
- LowFlaxAcross 3 studies, 1 reported a small beneficial effect and 2 reported neutral results. The median study duration was 49 days (4+ weeks). The predominant effect size was mixed (small beneficial and small neutral across studies). The single beneficial study used a dose of 25 mL/day in adults with metabolic syndrome. The evidence base is too small to draw firm conclusions. · Dose: 25 mL/day (based on 1 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
- 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
- LowFenugreek SeedAcross 3 studies, only 1 reported a beneficial small effect on diastolic blood pressure, while 2 found neutral effects. The single beneficial result came from a small trial in Alzheimer's patients using 5 cc of fenugreek seed extract daily for 120 days. The median study duration was 88 days, suggesting effects may require several weeks to emerge, but the evidence is too sparse to confirm a reliable benefit.1 beneficial2 neutral3 studies