L-Citrulline and Reduced Diastolic Blood Pressure

Research synthesisLow evidenceMixed effect size6 studies · 3 beneficial · 3 neutral · 0 harmful

Across 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.

Effective dose range: 6-10 g/day
Studied populations: older adults, postmenopausal women, and pregnant women with chronic hypertension

Caveats: Evidence is mixed: half of the studies show no significant benefit, and the two meta-analyses reached conflicting conclusions (2018 meta-analysis found no effect; 2025 meta-analysis found a significant reduction, but that analysis included a subgroup combining L-citrulline with L-arginine). Pure L-citrulline alone may have a weaker or inconsistent effect. Many studies had small sample sizes, and the median study duration is only 28 days, limiting long-term inferences.

Generated Jul 13, 2026

Doses used in studies

g/day: 6–10 (median 6, IQR 6–8) — 3 studies

Time to effect

Median: 4 weeks · IQR 3 weeks–6 weeks · Range 2 weeks–8 weeks — Reported in 3 of 6 studies

6 of 6 papersPopulation:

Does l-citrulline supplementation and watermelon intake reduce blood pressure in middle-aged and older adults? A systematic review and meta-analysis of randomized controlled trials.
- 2025-10
- Meta-Analysis · n = 415
- Clinical nutrition ESPEN 69
- - Ping Luo
  - Jingfeng Chen
  - Kang Liu
  - Jia Zhang
- PubMed: 40789388
- DOI: 10.1016/j.clnesp.2025.07.1130
2 Insights on
- Reduced Diastolic Blood Pressure
- High evidence
- Elderly
Subgroup analysis showed that the combined supplementation of l-citrulline and l-arginine significantly decreased DBP (-4.86 mmHg [95 % CI: -7.93 to -1.79], P = 0.002)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
L-Citrulline supplementation attenuates aortic pulse pressure and wave reflection responses to cold stress in older adults.
- 2022-03
- RCT
- Experimental gerontology 159
- - Salvador J Jaime
  - Jessica Nagel
  - Arun Maharaj
  - Stephen M Fischer
  - Elizabeth Schwab
  - Christopher Martinson
  - Kim Radtke
  - Richard P Mikat
  - Arturo Figueroa
- PubMed: 34990772
- DOI: 10.1016/j.exger.2021.111685
8 Insights on
- Reduced Diastolic Blood Pressure
- High evidence
- Elderly
Pb (Δ-4 ± 6 vs. Δ2 ± 6 mmHg; P = 0.008) ... responses to the CPT were significantly attenuated following L-CIT supplementation vs. placebo.
Effect
Beneficial
Effect size
Small
Significant
Yes
Dose
6 g/day
Effects of L-Citrulline Supplementation on Endothelial Function and Blood Pressure in Hypertensive Postmenopausal Women.
- 2022-10-20
- RCT
- Nutrients 14(20)
- - Arun Maharaj
  - Stephen M Fischer
  - Katherine N Dillon
  - Yejin Kang
  - Mauricio A Martinez
  - Arturo Figueroa
- PubMed: 36297080
- DOI: 10.3390/nu14204396
5 Insights on
- Reduced Diastolic Blood Pressure
- High evidence
- Rigorous Journal
- Clinical
The abstract does not report significant changes in resting brachial BP; only aortic BP changes were significant. Brachial BP was assessed but no significant effect reported.
Effect
Neutral
Effect size
Small
Significant
No
Dose
10 g
Effect of L-Citrulline Supplementation on Blood Pressure: a Systematic Review and Meta-Analysis of Clinical Trials.
- 2018-10-03
- Meta-Analysis
- Current hypertension reports 20(11)
- - Mohammad Sadegh Mirenayat
  - Sajjad Moradi
  - Hamed Mohammadi
  - Mohammad Hossein Rouhani
- PubMed: 30284051
- DOI: 10.1007/s11906-018-0898-3
2 Insights on
- Reduced Diastolic Blood Pressure
- High evidence
- Clinical
Also, there was no changes in aortic ... diastolic (change 0.26 mmHg; 95% CI -2.27, 2.80 mmHg) blood pressure after L-citrulline supplementation.
Effect
Neutral
Effect size
Small
Significant
No
CHronic hypERtension and L-citRulline studY (CHERRY): an Early-Phase Randomised Controlled Trial in Pregnancy.
- 2023-10-03
- RCT · n = 24
- Reproductive sciences (Thousand Oaks, Calif.) 31(2)
- - Laura Ormesher
  - Stephanie A Worton
  - Ashley Best
  - Susanna R Dodd
  - Alice Dempsey
  - Elizabeth C Cottrell
  - Heather Glossop
  - Catherine Chmiel
  - Hoi Yee Wu
  - Ben Hardwick
  - Sophie Hennessy
  - Edward D Johnstone
  - Jenny E Myers
- PubMed: 37789125
- DOI: 10.1007/s43032-023-01335-4
4 Insights on
- Reduced Diastolic Blood Pressure
- High evidence
- Clinical
L-citrulline had no effect on diastolic BP (L-citrulline: -1.82 95% CI (-5.86, 2.22) vs placebo: -5.00 95% CI (-12.76, 2.76))
Effect
Neutral
Effect size
Small
Significant
No
Dose
3-g L-citrulline twice daily
The Effects of Oral l-Arginine and l-Citrulline Supplementation on Blood Pressure.
- 2019-07-22
- Review
- Nutrients 11(7)
- - David Khalaf
  - Marcus Krüger
  - Markus Wehland
  - Manfred Infanger
  - Daniela Grimm
- PubMed: 31336573
- DOI: 10.3390/nu11071679
2 Insights on
- Reduced Diastolic Blood Pressure
- Moderate evidence
- Rigorous Journal
The antihypertensive properties of Cit are more questionable, but are likely in the range of 4.1/2.08 to 7.54/3.77 mmHg
Effect
Beneficial
Effect size
Moderate
Significant
Yes

L-Citrulline and Reduced Diastolic Blood Pressure

Does l-citrulline supplementation and watermelon intake reduce blood pressure in middle-aged and older adults? A systematic review and meta-analysis of randomized controlled trials.

L-Citrulline supplementation attenuates aortic pulse pressure and wave reflection responses to cold stress in older adults.

Effects of L-Citrulline Supplementation on Endothelial Function and Blood Pressure in Hypertensive Postmenopausal Women.

Effect of L-Citrulline Supplementation on Blood Pressure: a Systematic Review and Meta-Analysis of Clinical Trials.

CHronic hypERtension and L-citRulline studY (CHERRY): an Early-Phase Randomised Controlled Trial in Pregnancy.

The Effects of Oral l-Arginine and l-Citrulline Supplementation on Blood Pressure.