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L-Citrulline and L-Arginine: This One-Two Amino Acid Punch Can Improve Circulation—And Your Love Life!

L-Citrulline and L-Arginine: This One-Two Amino Acid Punch Can Improve Circulation—And Your Love Life!

Scientific studies show the combination of L-Citrulline and L-Arginine increases Nitric Oxide production for cardiovascular, immune boosting, and sexual health benefits!

You have probably heard of the amino acid L-arginine, which is also called simply arginine.

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It is well known in the nutrition science community for its ability to increase nitric oxide production resulting in a wide variety of health benefits. But you probably have not heard much about its powerful amino acid cousin, L-citrulline, or just citrulline.

If you eat at least six cups of watermelon every day then you’re getting an adequate dose of the amino acid citrulline. Citrulline’s name is actually derived from the Latin word for watermelon—citrullus—because it was first isolated from the fruit in 1930.1

What does L-Citrulline and L-Arginine do?

Together they help:

  • Support cardiovascular health by boosting nitric oxide production and helping blood flow more easily throughout the body
  • Support healthy blood pressure and boost the immune system
  • Detoxify the liver and eliminate ammonia from the body
  • Improve sexual stamina and enhance recovery from an intense workout

Who might benefit from taking a supplement containing
both citrulline and arginine?

  • Anyone who wants to support healthy blood pressure Individuals who want to avoid angina (chest pain)
  • Individuals who want to avoid leg pain due to poor blood circulation
  • Anyone who wants protection from heart attack and stroke
  • Men suffering from erectile dysfunction
  • Athletes who want a faster recovery

How are citrulline and arginine related?

As soon as citrulline enters the kidney, vascular endothelium and other tissues, it is converted into arginine. Plasma and tissue levels of arginine increase, which is necessary for the production of nitric oxide and relaxation of blood vessels. An additional benefit of supplemental citrulline is that it helps eliminate ammonia, a highly toxic substance, from the liver.

Will citrulline and arginine help my sex life?

The answer is yes. Arginine has been well studied for its ability to enhance sexual satisfaction. Both men and women report longer and more intense orgasms when their intake of arginine increases. Additionally, arginine is often used by men to achieve long lasting and harder erections. Since citrulline is a precursor for arginine and arginine is a precursor to nitric oxide, you can combine the two for enhanced sexual pleasure and vascular health.

But you’re probably not eating six cups of watermelon every day, and actually it isn’t recommended. Watermelon is high in fructose (fruit sugar) and it’s a natural diuretic, so you’d be spending a whole lot of time in the bathroom.

In addition to watermelon, citrulline is found in cucumbers and cantaloupe, at very low levels, as well as the milk protein casein. But since it is a nonessential amino acid, you don’t have to rely on getting citrulline from food. It is manufactured from other nutrients in your body, however, you only manufacture it if you are young
and healthy and producing those other essential nutrients in adequate amounts!

The citrulline and arginine combination plays an essential role in your body

Citrulline, like arginine, is important in vasodilation, the widening of blood vessels, resulting from relaxation of smooth muscle cells within the vessel walls, especially in the large arteries and veins and smaller arterioles.

The endothelium (inner lining) of blood vessels uses nitric oxide to signal the surrounding smooth muscle to relax. This results in a relaxing of the blood vessels, and increased blood flow.

In the body, citrulline is converted to the amino acid arginine, which goes on to make another important substance—nitric oxide. When citrulline enters the kidney, vascular endothelium and other tissues, it can be readily converted to arginine, thus raising plasma and tissue levels of arginine and enhancing nitric oxide

The importance of nitric oxide to healthy blood flow

As stated, nitric oxide is integral to relaxing blood vessels which is necessary for healthy blood flow to the heart and genital area in both men and women, and throughout the body. Nitric oxide helps the blood vessels maintain their flexibility so that the blood flow is unrestricted. This, in turn, helps maintain healthy blood pressure, and a healthy sexual response.

When your vascular system is working efficiently there is less chance that a blood clot will form, which means there is less chance of having a heart attack or stroke.

Nitric oxide helps prevent blood clots because it prevents blood aggregation or platelets from becoming sticky. When platelets are not sticky they can move in a single file through the capillaries.

But if they are sticking together it’s like trying to move a dozen people through a crack in the wall. There is nowhere for the platelets to go, so a blood clot forms.

Additionally, nitric oxide works as an antioxidant that reduces the possibility of immune cells adhering to artery walls. This helps keep down inflammation,
which most health professionals agree is a major cause of the plaque formation that contributes to atherosclerosis.

What inhibits adequate nitric oxide production?

  • People who have atherosclerosis, diabetes or hypertension (high bloodpressure) often show impaired nitric oxide pathways.3
  • Over-consumption of salt can impair nitric oxide production.4
  • Aging—as we get older there is a decrease in nitric oxide production because the body makes less citrulline and arginine.5

Boosting nitric oxide production with nutritional supplements

Supplemental arginine helps the body produce more nitric oxide, and it helps with conditions that improve when blood vessels are relaxed, such as atherosclerosis
and intermittent claudication (difficulty walking due to pain in leg muscles because of inadequate blood supply).

Even more importantly, new studies are showing that supplemental citrulline also assists in nitric oxide production by boosting blood levels of arginine. It does this because it is more readily absorbed and bioavailable than arginine alone, and it bypasses metabolism in the liver and gastrointestinal tract and is readily absorbed in the kidneys.6, 7

Citrulline and argininescientific studies

In the first study to show that oral supplementation with citrulline raises blood levels of arginine, 20 healthy volunteers were given 6 different dosing regimens of placebo, citrulline, and arginine.

After one week of oral supplementation, the citrulline dose increased plasma arginine concentration more effectively than arginine alone.8

A study in humans also showed the citrulline supplementation’s “time release” effect on arginine production. In this study an oral dose of 3.8 grams of citrulline resulted in a 227% peak increase in plasma arginine levels after 4 hours, compared with a 90% peak increase with the same dose of arginine.7,9

Thus, acute oral administration of citrulline appears to be considerably more efficient at raising plasma levels of arginine over the long term than arginine itself.7

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Editor's Note:

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  1. Collins JK, Wu G, Perkins-Veazie P, Spears K, Claypool PL, Baker RA, Clevidence BA. Nutrition. 2007 March.

  2. Romero MJ, Platt DH, Caldwell RB, Caldwell RW. Therapeutic use of citrulline in cardiovascular disease. Cardiovasc Drug Rev. 2006 Fall-Winter;24(3-4):275-90.

  3. Dessy, C.; Ferron, O. (2004). "Pathophysiological Roles of Nitric Oxide: In the Heart and the Coronary Vasculature". Current Medical Chemistry – Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry 3 (3): 207–216. 

  4. Osanai, T; Fujiwara, N; Saitoh, M; Sasaki, S; Tomita, H; Nakamura, M; Osawa, H; Yamabe, H et al. (2002). "Relationship between salt intake, nitric oxide and asymmetric dimethylarginine and its relevance to patients with end-stage renal disease.". Blood purification 20 (5): 466–8. doi:10.1159/000063555. PMID 12207094

  5. Kang L, Reyes RA, Delp, JM. Aging impairs flow-induced dilation in coronary arterioles: role of NO and H2O2. Am J Physiol Heart Circ Physiol. 2009 September; 297(3): H1087–H1095. Published online 2009 July 17. doi:

  6.  Cynober L. Pharmacokinetics of arginine and related amino acids. J Nutr. 2007 Jun;137(6 Suppl 2):1646S-1649S. 

  7. Romero M, Platt D, Caldwell R, Caldwell R. Therapeutic Use of Citrulline in Cardiovascular Disease. Cardiovascular Drug Reviews Vol. 24, No. 3–4, pp. 275–290.

  8. Schwedhelm E, Maas R, Freese R, Jung D, Lukacs Z, Jambrecina A, Spickler W, Schulze F, Boger RH.  Pharmacokinetic and pharmacodynamic properties of oral Citrulline and Arginine: impact on nitric oxide metabolism. Br J Clin Pharmacol. 2008 Jan;65(1):51-9. Epub 2007 Jul 27.

  9. Kuhn KP, Harris PA, Cunningham GR, Robbins IM, Summar ML, Christman BW. Oral citrulline effectively elevates plasma arginine levels for 24 h in normal volunteers. Circulation AHA Scientific Sessions 2006; abstract 1692, p. II-1339.

  10. Figueroa A, Trivino JA, Sanchez-Gonzalez MA, Vicil F. Oral Citrulline supplementation attenuates blood pressure response to cold pressor test in young men. Am J Hypertens. 2010 Jan;23(1):12-6. Epub 2009 Oct 22.

  11. Sureda A, Cordova A, Ferrer MD, Tauler P, Perez G, Tur JA, Pons A. Effects of Citrulline oral supplementation on polymorphonuclear neutrophils oxidative burst and nitric oxide production after exercise. Free Radic Res. 2009 Sep;43(9):828-35. Epub 2009 Jul 6.

  12. Chinda D, Nakaji S, Umeda T, Shimoyama T, Kurakake S, Okamura N, Kumae T, Sugawara K. A competitive marathon race decreases neutrophil functions in athletes.Luminescence. 2003 Nov-Dec;18(6):324-9.

  13.  Halstead, Bruce W., M.D. The Science of EDTA Chelation Therapy. Golden Quill Publishers, Inc., Colton, CA., 1979.

  14. Robbins, S.L.; Cotran, R.S.: and Kumar, V., eds. Pathological Basis of Disease. New York: W.B. Saunders, 1984.

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i have been using L-Arginine for 20 yrs. But, I haven’t used L-citrulline before. I will try it. Thanks a lot.

Whats the maximum dosage for a person with ED?  How many times a day should one take L-Arginine/L-Citruline for a boost in Nitric Oxide ?

Many Thanks,
V. W. Johnson

Is there any worry with diabetes? Or other health problems that a person should know before taking? Like throid problem/Diabetes?

I would like to know , what is the best L-Arginine and L Citrulline to take ,and how much can you take in one day ? And were is the best place to buy it at ?

I would like answers to above questions,please.Best brand of combination to take.Proper dosage and amount of times to take daily.Any medical conditions need to be considered?Any pertinate information appreciated.Thanks.

Answers to the above questions

Where can I order L-citulline and L-arginine?  Is it safe to use with diabetes 2 and ED problems?

I am an independent distributor for Herbalife and we have a product that has both of these amino acids in it! Please get in touch either via here or email .(JavaScript must be enabled to view this email address) if you would like more info or to place an order!

can you combine l arginine with Cialis or Viagra to enhance erections

I have done so and I find that I only need half the amount of Cialis or Viagra. My preference, however, is the amino acid L-citrulline combined with Cialis.

amzing fruit,somethink we eat tomato in the burger few tomato for make delicious, but we don’t know if tomato have a important nutrition special for to reduce cancer risk.

Brand name of product containing l-argenine and l-cetruline

now foods makes an excellent argenine citruline supplement.

We are independent distributor for Synergy Worldwide and we have a product ProArgi-9 Plus that has both of these amino acids conbined.
Susan and myself have been taking ProArgi-9 Plus for some time now and the affects on Susan and myself have been a profound positive experience Susan was suffering from hypertension and myself had high cholesterol problems with a high probability of heart disease, a friend of Susan’s introduced us to the Synergy V3 products, that was 6 months ago, Susan blood pressure has dropped from 158 over 95 back down to normal 110 over 75 and my cholesterol dropped down to normal and my doctor advised me there was no more need for me to take statin drugs, I had been on Lipitor for over 5 years to maintain normal cholesterol levels, but that’s not the best part we both feel much better, have more energy and confident, we sleep well look well. We have firmed up and lost weight, we trust you will have the same profound positive experience as we have had with these products
Our mission is to save a million lives through educating people about the amazing possibilities of the these amino acid L-arginine and L-cictrulline and the effects it has on the human body. 
Please get in touch either via here or email .(JavaScript must be enabled to view this email address) if you would like more information.

I’m a long time sufferer of ED. I’m thinking about trying the combination..L-arginine and L-citrulline. What would be the daily dosage (protocal) on takeing the two together?.. Thanks…Pete

Regarding combining L-citruline with Viagra or Cialias, multiple sources including WebMd say don’t do it as it can lead to dangerous drops in blood pressure.  I’d definatley check into this further before combining the two.

For Pete, you can visit
I am an independent distributor of SWW we have a newly launch product which has both L-Arginine and L-Citrulline. L-Citrulline allows for longer production of Nitric Oxide.
It has been recommended 1 serving per day - ie 1 scoop providing 5g L-Arginine & enough L-Citrulline combination for the best result)

Thanks for the web site and the info. I’ll go there and check it out..Thanks….Pete

I have been using L-Arginine in supplementation of 2000 mg a day for the last three and a half years. Recently I began juicing watermelon rinds as a base for my Kale juice and this contains large amounts of Citroline. The combination has done wonderful things for my sexual stamina and my workout stamina. I seldom need to use my Viagra any more and have sex frequently. I would heed the warnings of doubling up on L-Arginine and Viagra and/or Cialis because frankly I think the L-Arginine alone does wonders for blood pressure and circulation in general. And sexual ED is really a failure of a healthy blood circulation system. Good luck.

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