Citrulline

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    Last Updated: November 2, 2023

    L-Citrulline, or simply just citrulline, is a nonessential amino acid. It is efficiently turned into L-arginine in the kidneys after supplementation, which makes it a good choice for increasing nitric oxide synthesis in the body.

    Citrulline is most often used for .

    What is citrulline?

    Citrulline is one of the three dietary amino acids in the urea cycle (the other two are L-arginine and L-ornithine). Taking citrulline increases plasma levels of arginine and improves the ammonia recycling process and nitric oxide metabolism. Consequently, citrulline may be useful in situations in which nitric oxide is relevant, such as athletic performance, vascular health, and erectile dysfunction. There are very few foods that have useful amounts of citrulline, but watermelon is a notable exception. The two most common forms of citrulline are L-citrulline and citrulline malate.

    What are citrulline’s main benefits?

    There is limited evidence that citrulline supplementation can reduce ratings of perceived exertion, decrease muscle soreness, and increase power output and total repetitions performed in resistance training.[1][2][3] More research is needed to determine whether different supplement dosages, different formulations, or longer periods of ingestion can further improve exercise performance.

    A considerable amount of research suggests that supplementation with citrulline mildly reduces blood pressure.[4] More research is needed on citrulline’s potential effects for erectile dysfunction, but a small amount of research suggests a beneficial effect.[5]

    What are citrulline’s main drawbacks?

    Although the safety of long-term supplementation with high doses of citrulline warrants further investigation, research to date suggests that it is well tolerated in most individuals. Unlike arginine and ornithine, high doses of citrulline don't seem to result in gastrointestinal distress.[2]

    How does citrulline work?

    Citrulline supplementation increases the body’s arginine levels. Because arginine is the main substrate for the synthesis of nitric oxide, citrulline ingestion can indirectly increase nitric oxide production. In turn, given the role of nitric oxide in vasodilation, mitochondrial respiration, calcium handling, and glucose uptake, greater amounts of nitric oxide can theoretically improve circulatory health and muscle function and reduce fatigue.

    What are other names for Citrulline

    Note that Citrulline is also known as:
    • L-Citrulline
    • Stimol (Brand Name)
    • citrulline malate

    Dosage information

    To supplement L-citrulline for circulatory health or to alleviate erectile dysfunction, take 2,000 mg of citrulline, three times a day with meals, for a total daily dose of 6,000 mg. L-citrulline does not need to be taken with meals, however.

    To supplement for circulatory health with a citrulline malate supplement, take 1.76 g of citrulline malate for every 1 gram of citrulline you would normally take.

    To supplement L-citrulline to enhance sports performance, take 6,000 – 8,000 mg of citrulline malate about an hour before exercise. On days that you don't exercise, it can be broken up into smaller doses.

    Examine Database: Citrulline

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    Frequently asked questions

    What is citrulline?

    Citrulline is one of the three dietary amino acids in the urea cycle (the other two are L-arginine and L-ornithine). Taking citrulline increases plasma levels of arginine and improves the ammonia recycling process and nitric oxide metabolism. Consequently, citrulline may be useful in situations in which nitric oxide is relevant, such as athletic performance, vascular health, and erectile dysfunction. There are very few foods that have useful amounts of citrulline, but watermelon is a notable exception. The two most common forms of citrulline are L-citrulline and citrulline malate.

    What’s the difference between L-citrulline and citrulline malate?

    L-citrulline is often combined with malate, an intermediary of the Krebs cycle. In theory, supplementing with malate could increase ATP production, potentiating L-citrulline's ergogenic effects.[6] Although there has been some promising research showing that citrulline malate can improve exercise performance[3], it’s unclear whether citrulline malate is superior to citrulline, as there is currently no research directly comparing the two.

    Which foods are rich in citrulline?

    Citrulline is highest in watermelon (where it derives its name, as watermelons are known as Citrullus vulgaris[7]), which contains an average of 2.1 milligrams of citrulline per gram of wet weight (although absolute numbers vary).[8] Consuming watermelon has been noted to acutely increase both plasma arginine and citrulline (3.3 kilograms of watermelon is equivalent to 10 grams of supplemental L-arginine)[9][10] and to increase fasting arginine and ornithine in the range of 12%–22% following consumption of 780–1560 grams daily.[11]

    Other food sources of citrulline include muskmelons (cantelope), bitter melons, squashes, gourds, cucumbers, and pumpkins.[7]

    What are citrulline’s main benefits?

    There is limited evidence that citrulline supplementation can reduce ratings of perceived exertion, decrease muscle soreness, and increase power output and total repetitions performed in resistance training.[1][2][3] More research is needed to determine whether different supplement dosages, different formulations, or longer periods of ingestion can further improve exercise performance.

    A considerable amount of research suggests that supplementation with citrulline mildly reduces blood pressure.[4] More research is needed on citrulline’s potential effects for erectile dysfunction, but a small amount of research suggests a beneficial effect.[5]

    Does citrulline improve exercise performance?

    Citrulline has been touted as an ergogenic aid due to its promotion of vasodilation and blood flow by indirectly increasing nitric oxide synthesis. However, research on citrulline suggests that its effect on exercise performance is not as substantial as some claim.

    For instance, 2 meta-analyses found that citrulline supplementation did not improve strength[12] or measures of aerobic exercise performance,[13] whereas other meta-analyses found that supplementation with citrulline reduced rating of perceived exertion (a subjective measure of the difficulty of an exercise), decreased muscle soreness, and increased power output and total repetitions performed in resistance training.[1][2][3]

    It’s important to note that these mixed findings may be related to variations in study populations, doses, formulations, or lengths. Although certain studies found that supplemental citrulline does not improve some aspects of exercise performance, the totality of the evidence shows that it may be mildly helpful for some aspects of resistance training. Further research is needed to see whether changing these variables (e.g., higher doses) can improve exercise performance.

    Does citrulline reduce blood pressure?

    Citrulline supplementation has been presented as a way of lowering blood pressure due to its capacity to boost nitric oxide production, a vasodilator. One meta-analysis does suggest that supplementation with citrulline can mildly decrease blood pressure, but because the participants were limited to healthy individuals, more research is needed to see whether this decrease applies to people with high blood pressure.[4] It’s also unclear whether certain forms (e.g., L-citrulline, citrulline malate, or citrulline from watermelon juice), higher doses (ranging from 2 to 8 grams in many studies), or increased lengths of supplementation reduce blood pressure further.

    Can citrulline help improve symptoms of erectile dysfunction?

    Citrulline is thought to be a proerectile agent because it is a precursor for arginine, and arginine is the substrate from which nitric oxide is produced and then can induce cGMP (via the NO/cGMP/VEGF pathway);[32] an increase in cGMP is also the ultimate effect of PDE5 inhibitors such as sildenafil (also known as Viagra) or icariin from horny goat weed.[33]

    In men with erectile dysfunction (as assessed by weak erections and erectile hardness score[34]) who were given 1,500 mg of citrulline daily (two doses of 750 mg) for one month, half of the 24 participants reported a benefit (as assessed by “very satisfied” with treatment), whereas there was an 8.3% improvement in the placebo group.[5]

    Citrulline appears to have proerectile properties that occur vicariously through arginine. It is likely more potent than arginine due to greater bodily exposure to arginine, but the preliminary evidence does not suggest that it is more potent than the reference drug sildenafil.

    What are citrulline’s main drawbacks?

    Although the safety of long-term supplementation with high doses of citrulline warrants further investigation, research to date suggests that it is well tolerated in most individuals. Unlike arginine and ornithine, high doses of citrulline don't seem to result in gastrointestinal distress.[2]

    Are there any side effects of taking high doses of citrulline?

    In humans, a 15-gram dose of citrulline taken acutely (in the short term) does not appear to cause diarrhea or intestinal upset.[31] In this respect, citrulline is notably different from both ornithine and arginine, which may cause diarrhea at 10-gram doses when taken in boluses[35][36] due to limited absorption of these amino acids, which then proceed to the colon to cause osmotic diarrhea.[35]

    How does citrulline work?

    Citrulline supplementation increases the body’s arginine levels. Because arginine is the main substrate for the synthesis of nitric oxide, citrulline ingestion can indirectly increase nitric oxide production. In turn, given the role of nitric oxide in vasodilation, mitochondrial respiration, calcium handling, and glucose uptake, greater amounts of nitric oxide can theoretically improve circulatory health and muscle function and reduce fatigue.

    How is citrulline created in the body?

    Citrulline is created in the body by one of two pathways, either recycled from arginine (the conversion of arginine into nitric oxide leaves citrulline as a byproduct)[14][15] or produced from the nitrogen (and some carbon) contained in L-glutamine,[16] a process in which the enzyme ornithine transcarbamylase uses both ornithine and carbamoyl phosphate (which requires glutamine) to produce citrulline in enterocytes.[17][18]

    It appears that the arginine pathway accounts for about 10% of circulating citrulline and the glutamine pathway accounts for 90%;[14] reducing plasma glutamine levels can reduce plasma citrulline.[19]

    Where is citrulline metabolized in the body after consumption?

    The majority of citrulline either floats in the blood passively or is transported to the kidneys for conversion into arginine. Therefore, most bioactivities of citrulline are secondary to arginine ingestion.

    Approximately 83% of orally ingested citrulline appears to be taken up by the kidneys,[20][21][22] where it is converted into L-arginine in the proximal tubules (via the enzymes arginosuccinate synthase and arginosuccinate lyase[23]); this conversion of citrulline into arginine (either from supplemental citrulline or that produced as a byproduct of arginine creation of nitric oxide) accounts for 5%–15% of circulating arginine but 60% of total arginine (the difference being due to the ability of arginine to be incorporated into proteins).[19][24]

    Does citrulline impact muscle protein synthesis?

    Although citrulline does not appear to be an activator of mTOR, like leucine, (mTOR activation, via S6K, induces muscle protein synthesis), citrulline does appear to restore muscle protein synthesis rates[25][26] and muscular function after food restriction,[27] and this positive effect on muscle protein synthesis is abolished by rapamycin and is thus mediated by the mTORc1 pathway.[28][29]

    Citrulline does not activate the p44/42 MAPK pathway or the ERK1/2 pathway in skeletal muscle,[25] whereas leucine itself can activate ERK1/2 and induce 4E-BP1 (downstream of mTOR) to a much larger degree than citrulline.[25]

    Citrulline positively influences the mTOR pathway but does not appear to occur through direct activation, as with leucine. At minimum, citrulline normalizes suppressed mTOR signaling.

    In human studies, supplementation with 0.18 g/kg of citrulline per day for one week did not significantly modify leucine oxidation rates or whole-body protein synthesis,[30] but elsewhere, at the same dosage, it has been noted to improve nitrogen balance in humans in the fed state.[19] Oral doses of citrulline between 2 and15 grams do not appear to acutely affect urinary nitrogen in the fasted state.[31]

    Mixed evidence as to whether citrulline supplementation can help with muscle protein synthesis

    Does citrulline interact with other nutrients, supplements, or medications?

    Nutrient-Nutrient Interactions

    Branched Chain Amino Acids (special reference to Leucine)

    Branched-chain amino acids (BCAAs) are a group of three amino acids (leucine, isoleucine, and valine) that are involved in skeletal muscle synthesis and degradation. Of these three, leucine is commonly said to be the most “important” because it is the prime mediator of muscle protein synthesis (and appears to be the most common reason for supplementation with BCAAs).

    When looking at citrulline ingestion at rest, a dose of 0.18 g/kg was found to improve nitrogen balance in one study when ingested in the fed state[19] whereas another study noted a failure with the same dose; both whole-body protein synthesis and leucine oxidation rates were unaffected.[30]

    During exercise, 6 grams of citrulline taken by trained cyclists prior to a 137 km cycling test produced a reduction in plasma BCAAs relative to the control, and this effect was attributed to increased utilization of BCAAs for fuel.[37]

    Citrulline does appear to interact with BCAA metabolism in the body, although human studies have produced differing results based on the context of the study.

    Similar to how citrulline is able to restore muscle protein synthesis rates[25]PMD:16608884 and muscular function[27] during aging and malnourishment in rats via mTORc1-dependent means,[28][38] citrulline itself is a weak agonist (enough that it could be false positive from sensitizing mTORc1[25]). Conversely, leucine itself is a potent activator of mTORc1 activity.

    Citrulline may positively mediate leucine's signaling through mTOR, which theoretically suggests that they are synergistic. The application of this combination in weight lifters has not yet been investigated, so the synergism is currently just a hypothesis rather than a demonstrated fact.

    Glutathione

    Citrulline increases levels of nitric oxide (NO), a vasodilator. Although NO effects are potent, the extent of vasodilation is limited by the short half life of NO, which is broken down by oxidation soon after it is formed.[39] One study found that taking reduced glutathione (GSH; a reducing agent) alongside citrulline may help to protect against the rapid oxidative destruction of NO. In vitro studies in human umbilical vein endothelial cells demonstrated that citrulline (0.3 mM) in combination with GSH (1 mM) resulted in significantly greater nitrite levels than vehicle-treated controls or citrulline alone. Similarly, 3-day treatment of rats with citrulline (500 mg/kg/day) and GSH (50 mg/kg/day) by oral gavage increased plasma nitric oxide levels more than a control or citrulline alone. The investigators also conducted a small human trial in which resistance-trained men were randomly assigned to orally ingest either a placebo or L-citrulline (2 g/day), GSH (1 g/day), or citrulline (2 g/day) in combination with GSH (200 mg/day) for 7 days, followed by a resistance exercise session. Consistent with in vitro and rat studies, participants who took GSH along with citrulline had significantly higher nitrite and nitric oxide levels at 30 minutes after exercise relative to placebo or citrulline alone.[39]

    Supplementing with reduced glutathione (GSH) alongside citrulline may extend the half life of nitric oxide, potentially resulting in greater vasodilation compared to L-citrulline alone.

    Nitrate

    Nitrate is a small nitric oxide donor that is the main bioactive of beetroot juice.

    Serum nitrite (reduced form of nitrate) appears to be increased during exercise after consumption of 6 grams of citrulline malate, which is thought to be an indicator of increased nitric oxide production.[40]

    Sodium Bicarbonate

    Sodium bicarbonate (baking soda) is an ergogenic supplement that is reported to increase physical performance, and although it is somewhat unreliable overall in doing so, it appears to be effective for short-duration activities characterized by metabolic acidosis ('the burn').

    Citrulline administration appears to promote ureogenesis (production of urea) and secondarily promote the renal resorption of bicarbonate;[41] it is thought that citrulline may promote a slight buffering effect by preserving bicarbonate.[42]

    A study assessing the synergism between citrulline and bicarbonate supplementation is currently not available.

    Theoretically synergistic, but has not been directly investigated at this moment in time

    Statins

    One study in endothelial cells (in vitro) noted that the tested statin (simvastatin) was able to increase mRNA concentrations of eNOS (the enzyme in endothelial cells that produces nitric oxide from arginine) and thus was said to act synergistically with arginine and/or citrulline to improve blood pressure in participants with high cholesterol.[43]

    Because simvastatin,[43] atorvastatin,[44][45] and lovastatin[46] (bioactive in red yeast rice) have all been noted to increase eNOS,[44] iNOS,[44][46] and nNOS[45] it is thought that this is a mechanism common to statin drugs in general.

    Statin drugs may be able to increase expression of the enzyme that mediates the conversion of arginine into nitric oxide, and there is possible synergism for other processes pertaining to nitric oxide. This hypothesis has not yet been tested in a living system.

    Update History

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    References

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    Examine Database References

    1. Blood Lactate (Exercise) - Benjamin Wax, Andreas N Kavazis, Kevin Weldon, Joseph SperlakEffects of supplemental citrulline malate ingestion during repeated bouts of lower-body exercise in advanced weightliftersJ Strength Cond Res.(2015 Mar)
    2. Blood Lactate (Exercise) - Fatih Kiyici, Hüseyin Eroğlu, N Fazil Kishali, Guleda BurmaogluThe Effect of Citrulline/Malate on Blood Lactate Levels in Intensive ExerciseBiochem Genet.(2017 Dec)
    3. Blood Lactate (Exercise) - Andrew J Chappell, Daniel M Allwood, Trevor N SimperCitrulline Malate Fails to Improve German Volume Training Performance in Healthy Young Men and WomenJ Diet Suppl.(2020)
    4. Blood Lactate (Exercise) - Hickner RC, Tanner CJ, Evans CA, Clark PD, Haddock A, Fortune C, Geddis H, Waugh W, McCammon ML-citrulline reduces time to exhaustion and insulin response to a graded exercise testMed Sci Sports Exerc.(2006 Apr)
    5. Blood Lactate (Exercise) - Benjamin Wax, Andreas N Kavazis, William LuckettEffects of Supplemental Citrulline-Malate Ingestion on Blood Lactate, Cardiovascular Dynamics, and Resistance Exercise Performance in Trained MalesJ Diet Suppl.(2016)
    6. Blood Lactate (Exercise) - Eric T Trexler, Dale S Keith, Todd A Schwartz, Eric D Ryan, Lee Stoner, Adam M Persky, Abbie E Smith-RyanEffects of Citrulline Malate and Beetroot Juice Supplementation on Blood Flow, Energy Metabolism, and Performance During Maximum Effort Leg Extension ExerciseJ Strength Cond Res.(2019 Sep)
    7. Weight - Paul Hwang, Flor E Morales Marroquín, Josh Gann, Tom Andre, Sarah McKinley-Barnard, Caelin Kim, Masahiko Morita, Darryn S WilloughbyEight weeks of resistance training in conjunction with glutathione and L-Citrulline supplementation increases lean mass and has no adverse effects on blood clinical safety markers in resistance-trained malesJ Int Soc Sports Nutr.(2018 Jun 27)
    8. Fatigue Symptoms - Bendahan D, Mattei JP, Ghattas B, Confort-Gouny S, Le Guern ME, Cozzone PJCitrulline/malate promotes aerobic energy production in human exercising muscleBr J Sports Med.(2002 Aug)
    9. Fatigue Symptoms - Pérez-Guisado J, Jakeman PMCitrulline malate enhances athletic anaerobic performance and relieves muscle sorenessJ Strength Cond Res.(2010 May)
    10. Aerobic Exercise Metrics - Stephen J Bailey, Jamie R Blackwell, Terrence Lord, Anni Vanhatalo, Paul G Winyard, Andrew M Jonesl-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humansJ Appl Physiol (1985).(2015 Aug 15)
    11. Muscular Endurance - Adam M Gonzalez, Robert W Spitz, Jamie J Ghigiarelli, Katie M Sell, Gerald T MangineAcute Effect of Citrulline Malate Supplementation on Upper-Body Resistance Exercise Performance in Recreationally Resistance-Trained MenJ Strength Cond Res.(2018 Nov)
    12. Muscular Endurance - Glenn JM, Gray M, Wethington LN, Stone MS, Stewart RW Jr, Moyen NEAcute citrulline malate supplementation improves upper- and lower-body submaximal weightlifting exercise performance in resistance-trained femalesEur J Nutr.(2017 Mar)
    13. Power Output - Eric T Trexler, Adam M Persky, Eric D Ryan, Todd A Schwartz, Lee Stoner, Abbie E Smith-RyanAcute Effects of Citrulline Supplementation on High-Intensity Strength and Power Performance: A Systematic Review and Meta-AnalysisSports Med.(2019 May)
    14. Power Output - Glenn JM, Gray M, Jensen A, Stone MS, Vincenzo JLAcute citrulline-malate supplementation improves maximal strength and anaerobic power in female, masters athletes tennis playersEur J Sport Sci.(2016 Nov)
    15. Body Fat - Arturo Figueroa, Stacey Alvarez-Alvarado, Michael J Ormsbee, Takudzwa A Madzima, Jeremiah C Campbell, Alexei WongImpact of L-citrulline supplementation and whole-body vibration training on arterial stiffness and leg muscle function in obese postmenopausal women with high blood pressureExp Gerontol.(2015 Mar)
    16. Oxygen Uptake - John Ashley, Youngdeok Kim, Joaquin U GonzalesImpact of l-citrulline supplementation on oxygen uptake kinetics during walkingAppl Physiol Nutr Metab.(2018 Jun)
    17. Immunity - Sureda A, Cordova A, Ferrer MD, Tauler P, Perez G, Tur JA, Pons AEffects of L-citrulline oral supplementation on polymorphonuclear neutrophils oxidative burst and nitric oxide production after exerciseFree Radic Res.(2009 Sep)
    18. Plasma Arginine - Takashi Suzuki, Masahiko Morita, Yoshinori Kobayashi, Ayako KamimuraOral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover studyJ Int Soc Sports Nutr.(2016 Feb 19)
    19. Power Output - Joshua L Gills, Jordan M Glenn, Michelle Gray, Braden Romer, Hocheng LuAcute citrulline-malate supplementation is ineffective during aerobic cycling and subsequent anaerobic performance in recreationally active malesEur J Sport Sci.(2020 Feb 18)
    20. Rate of Perceived Exertion - Sean T Stanelle, Kelsey L McLaughlin, Stephen F CrouseOne Week of L-Citrulline Supplementation Improves Performance in Trained CyclistsJ Strength Cond Res.(2020 Mar)
    21. Heart Rate - Figueroa A, Trivino JA, Sanchez-Gonzalez MA, Vicil FOral L-citrulline supplementation attenuates blood pressure response to cold pressor test in young menAm J Hypertens.(2010 Jan)
    22. Heart Rate - Marcos Angel Sanchez-Gonzalez, Andrew Paul Koutnik, Katherine Ramirez, Alexei Wong, Arturo FigueroaThe effects of short term L-citrulline supplementation on wave reflection responses to cold exposure with concurrent isometric exerciseAm J Hypertens.(2013 Apr)
    23. Heart Rate - Arturo Figueroa, Stacey Alvarez-Alvarado, Salvador J Jaime, Roy Kalfonl-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight menBr J Nutr.(2016 Jul)
    24. Arterial Stiffness - Joaquin U Gonzales, Andrea Raymond, John Ashley, Youngdeok KimDoes l-citrulline supplementation improve exercise blood flow in older adults?Exp Physiol.(2017 Dec 1)
    25. Blood Pressure - Huan-Huan Yang, Xin-Li Li, Wei-Guo Zhang, Arturo Figueroa, Li-Hua Chen, Li-Qiang QinEffect of oral L-citrulline on brachial and aortic blood pressure defined by resting status: evidence from randomized controlled trialsNutr Metab (Lond).(2019 Dec 26)
    26. Blood Pressure - Powers R, et al[7-OR]: L-Citrulline administration increases the arginine/ADMA ratio, decreases blood pressure and improves vascular function in obese pregnant womenPregnancy Hypertens.()
    27. Blood Flow - Jeffrey M Rogers, Joshua Gills, Michelle GrayAcute effects of Nitrosigine® and citrulline malate on vasodilation in young adultsJ Int Soc Sports Nutr.(2020 Feb 24)
    28. Heart Rate - Brian Cunniffe, Maria Papageorgiou, Barbara OʼBrien, Nathan A Davies, George K Grimble, Marco CardinaleAcute Citrulline-Malate Supplementation and High-Intensity Cycling PerformanceJ Strength Cond Res.(2016 Sep)
    29. Aerobic Exercise Metrics - Harnden CS, Agu J, Gascoyne TEffects of citrulline on endurance performance in young healthy adults: a systematic review and meta-analysis.J Int Soc Sports Nutr.(2023-Dec)
    30. Total Antioxidant Capacity (TAC) - S Azizi, M Ebrahimi-Mameghani, M Mobasseri, N Karamzad, R MahdaviOxidative stress and nitrate/nitrite (NOx) status following citrulline supplementation in type 2 diabetes: a randomised, double-blind, placebo-controlled trialJ Hum Nutr Diet.(2020 Jul 19)
    31. Blood Pressure - Karla Balderas-Munoz, Lilia Castillo-Martínez, Arturo Orea-Tejeda, Oscar Infante-Vázquez, Marcelo Utrera-Lagunas, Raúl Martínez-Memije, Candace Keirns-Davis, Bryan Becerra-Luna, Gabriela Sánchez-VidalImprovement of ventricular function in systolic heart failure patients with oral L-citrulline supplementationCardiol J.(2012)
    32. Blood Pressure - Juan José Orozco-Gutiérrez, Lilia Castillo-Martínez, Arturo Orea-Tejeda, Oscar Vázquez-Díaz, Adrián Valdespino-Trejo, René Narváez-David, Candace Keirns-Davis, Olín Carrasco-Ortiz, Adolfo Navarro-Navarro, Rocío Sánchez-SantillánEffect of L-arginine or L-citrulline oral supplementation on blood pressure and right ventricular function in heart failure patients with preserved ejection fractionCardiol J.(2010)
    33. Muscle Soreness - da Silva DK, Jacinto JL, de Andrade WB, Roveratti MC, Estoche JM, Balvedi MCW, de Oliveira DB, da Silva RA, Aguiar AFCitrulline Malate Does Not Improve Muscle Recovery after Resistance Exercise in Untrained Young Adult MenNutrients.(2017 Oct 18)
    34. Blood Flow - Kim van Wijck, Karolina A P Wijnands, Dennis M Meesters, Bas Boonen, Luc J C van Loon, Wim A Buurman, Cornelis H C Dejong, Kaatje Lenaerts, Martijn PoezeL-citrulline improves splanchnic perfusion and reduces gut injury during exerciseMed Sci Sports Exerc.(2014 Nov)
    35. Heart Rate Variability - Casonatto J, et alCitrulline malate supplementation might potentiate post-exercise hypotension in hypertensives: A 24-hour analysisSci Sport.()
    36. High-density lipoprotein (HDL) - Ochiai M, Hayashi T, Morita M, Ina K, Maeda M, Watanabe F, Morishita KShort-term effects of L-citrulline supplementation on arterial stiffness in middle-aged menInt J Cardiol.(2012 Mar 8)
    37. Blood Pressure - Juliano Casonatto, Daniel Massaharu Enokida, Kamila GrandolfiInter-Individual Responses to Citrulline Malate Oral Supplementation on Post-Exercise Hypotension in Hypertensives: A 24-Hour AnalysisArq Bras Cardiol.(2019 Jul 10)
    38. Blood Pressure - Qiu J, et all-citrulline supplementation reduced peripheral blood pressure in Chinese adults with prehypertensionJ Hypertens.()
    39. Asthma Symptoms - Fernando Holguin, Hartmut Grasemann, Sunita Sharma, Daniel Winnica, Karen Wasil, Vong Smith, Margaret H Cruse, Nancy Perez, Erika Coleman, Timothy J Scialla, Loretta G QueL-Citrulline increases nitric oxide and improves control in obese asthmaticsJCI Insight.(2019 Dec 19)
    40. Heart Rate Variability - Alexei Wong, Oksana Chernykh, Arturo FigueroaChronic l-citrulline supplementation improves cardiac sympathovagal balance in obese postmenopausal women: A preliminary reportAuton Neurosci.(2016 Jul)
    41. Liver Fibrosis - Zahra Darabi, Mina Darand, Zahra Yari, Mehdi Hedayati, Amirhosein Faghihi, Shahram Agah, Azita HekmatdoostInflammatory markers response to citrulline supplementation in patients with non-alcoholic fatty liver disease: a randomized, double blind, placebo-controlled, clinical trialBMC Res Notes.(2019 Feb 15)
    42. Blood Pressure - Babak Sharif Kashani, Paritash Tahmaseb Pour, Majid Malekmohammad, Neda Behzadnia, Faezeh Sheybani-Afshar, Mohammad Fakhri, Samira Chaibakhsh, Farah Naghashzadeh, Salavan AidenlouOral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trialJ Cardiol.(2014 Sep)
    43. Growth Hormone - Sureda A, Córdova A, Ferrer MD, Pérez G, Tur JA, Pons AL-citrulline-malate influence over branched chain amino acid utilization during exerciseEur J Appl Physiol.(2010 Sep)
    44. Growth Hormone - C Moinard, I Nicolis, N Neveux, S Darquy, S Bénazeth, L CynoberDose-ranging effects of citrulline administration on plasma amino acids and hormonal patterns in healthy subjects: the Citrudose pharmacokinetic studyBr J Nutr.(2008 Apr)
    45. Insulin - Thibault R, Flet L, Vavasseur F, Lemerle M, Ferchaud-Roucher V, Picot D, Darmaun DOral citrulline does not affect whole body protein metabolism in healthy human volunteers: results of a prospective, randomized, double-blind, cross-over studyClin Nutr.(2011 Dec)
    46. Erections - Luigi Cormio, Mario De Siati, Fabrizio Lorusso, Oscar Selvaggio, Lucia Mirabella, Francesca Sanguedolce, Giuseppe CarrieriOral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunctionUrology.(2011 Jan)
    47. Blood Pressure - Heidi A B Smith, Jeffrey A Canter, Karla G Christian, Davis C Drinkwater, Frank G Scholl, Brian W Christman, Geraldine D Rice, Frederick E Barr, Marshall L SummarNitric oxide precursors and congenital heart surgery: a randomized controlled trial of oral citrullineJ Thorac Cardiovasc Surg.(2006 Jul)