L-Citrulline and Reduced Diastolic Blood Pressure

Research synthesisLow evidenceMixed effect size4 studies · 2 beneficial · 2 neutral · 0 harmful

Across 4 studies, 2 reported beneficial effects of L-citrulline on diastolic blood pressure, with effect sizes ranging from small to moderate, while 2 found neutral effects. The median study duration was 28 days (4 weeks), and the most-studied population was older adults (including middle-aged and elderly individuals). Doses ranged from 6 g/day to 10 g/day, though no single form was consistently used across studies.

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

Caveats: Evidence base is small (only 4 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. Most studies focused on clinical or elderly populations, and effects in healthier or younger adults remain unclear.

Generated Jun 11, 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 4 studies

4 of 4 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
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

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.

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