Benefits of L-citrulline for circulation and sexual health
Two quick questions
Have you noticed changes in the quality of your sex life over the years?
Are you looking for healthy alternatives to support optimal blood circulation?
If you are here, it might be because you have heard about the relationship between citrulline, a food supplement widely used among athletes, and intimate relationships. Logically, you will now be wondering: what exactly does it consist of? Is this association real and effective?
How blood flow improves your relationship
Nitric oxide and L-citrulline
As we get older, our body reduces the production of nitric oxide, the molecule responsible for opening blood vessels. To counteract this effect, nature offers a specific tool present in foods like watermelon: L-citrulline.
Blood circulation and quality of life
Sexual health is a fundamental pillar of overall human well-being, directly connected to quality of life, emotional balance, and cardiovascular health. However, it is often treated as an isolated topic, ignoring that the quality of our sexual relationships depends directly on basic physiological processes.
When the body does not respond as expected in intimacy, it is common for insecurities, frustration, or anxiety to appear. Although there are multiple psychological factors, the physical basis is undeniable:
Proper blood circulation is a key factor for a normal sexual response.
What L-citrulline is, in short
L-citrulline is a non-essential amino acid, which means that the human body is capable of synthesising it on its own. Its main function is framed within the urea cycle, a key metabolic process for eliminating toxins from the body.
How L-citrulline works
Its true value for vascular health lies in its capacity for transformation through a highly efficient biological chain:
- Intake: L-citrulline enters the bloodstream.
- Transformation: It travels to the kidneys, where it is converted into L-arginine.
- Activation: This arginine becomes the direct precursor to nitric oxide.
- Result: Greater release of nitric oxide to relax the walls of the blood vessels. The result? Better blood circulation.
Fun fact:
Its name comes from Citrullus lanatus, the scientific name for watermelon, the fruit in which it was first isolated and which represents one of its greatest natural sources.
Why blood circulation is important in sexual relationships
To understand how a simple amino acid like citrulline can impact sexual relationships, it is necessary to observe the body's mechanics during arousal. The physical response, in both men and women, depends on a process called vascular congestion.
Vascular congestion process
- The neural stimulus: When the brain perceives a stimulus, it sends signals to the tissues in the genital area.
- The release of the messenger gas: These signals instruct the endothelial cells (the inner layer of the blood vessels) to release nitric oxide.
- Vasodilation: This gas instructs the smooth muscles of the arteries to relax and widen.
In men, this blood flow is one of the main physical mechanisms involved in an erection.
In women, this same process promotes the lubrication and sensitivity necessary to maintain comfortable and pleasurable sexual intercourse.
Enemies of nitric oxide: age and stress
The circulatory system is highly sensitive to our lifestyle. There are two factors that sabotage the production of nitric oxide:
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Biological ageing
From the age of 40, the capacity of the blood vessels to produce nitric oxide decreases and they lose elasticity.
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Chronic stress
A fast-paced lifestyle keeps cortisol and adrenaline (vasoconstrictor hormones) levels high, prioritising blood flow to the survival muscles and reducing blood flow to the reproductive system.
L-citrulline and blood flow according to scientific studies
The use of natural supplementation to support vascular function does not seek to force an immediate mechanical response as a drug would, but rather to support the body's physiological processes. Clinical studies provide revealing data:
- Improved rigidity: A benchmark clinical study published in the journal Urology¹ evaluated men with mild difficulties maintaining rigidity. After one month of oral L-citrulline supplementation, a significant proportion of the subjects reported improvements in their function, according to the evaluation scales used in the study.
- Psychological well-being: The researchers highlighted an increase in the psychological satisfaction of the participants, reducing performance anxiety.
- Vascular function: Other research² has shown that sustained supplementation promotes vascular function, consolidating its role as a primary and natural support tool.
How to take L-citrulline
To obtain the circulatory benefits linked to performance and sexual health, research suggests that a regular dose is necessary. Obtaining these amounts exclusively through the diet is complex. One would have to ingest more than a kilo of watermelon daily (especially the rind, which we rarely eat) to achieve optimal levels. For this reason, isolating the amino acid in a pure format is the most practical and convenient option.
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Ideally, opt for L-citrulline powder obtained through natural fermentation (100% vegan and additive-free).
For an even more comprehensive approach, many people combine this vascular support with adaptogenic ingredients focused on desire, such as organic black maca. While citrulline facilitates the physical mechanism, maca acts on the perception of energy, creating an ideal synergy for couples.
Citrulline vs arginine, which one to take?
If it is L-arginine that ultimately produces nitric oxide, why not consume arginine directly instead of citrulline? The answer lies in the efficiency of the human body.
| Characteristic | L-arginine | L-citrulline |
|---|---|---|
| Passage through the liver | Suffers the "funnel effect". The enzyme arginase destroys most of it before it reaches the blood. | Bypasses the liver intact. It is not recognised nor destroyed by the arginase enzyme. |
| Absorption into the blood | Low. Very high doses are required for it to reach the peripheral tissues. | Very high. The kidneys progressively convert it into arginine on a sustained basis³. |
| Gastric tolerance | High doses can cause stomach discomfort or heaviness and diarrhoea. | Excellent. It does not cause gastric discomfort, even with regular intake. |
Side effects and contraindications of L-citrulline
Although L-citrulline is a highly studied amino acid with high digestive tolerance, its vasodilatory mechanism of action requires certain precautions.
It should never be combined with prescription medications for erectile dysfunction, and it should be avoided if taking nitrate drugs for heart problems or chronic blood pressure-lowering medications. The combination can cause a drastic and dangerous drop in blood pressure. As usual, due to a lack of studies, pregnant or breastfeeding women should abstain unless expressly indicated by a doctor.
Understanding your body to improve the quality of your sex life
We often attribute the ups and downs in our sexual relationships to mental blocks or the wear and tear of routine, forgetting that the body needs its own vascular mechanics to be in top condition in order to respond.
Supporting nitric oxide production through such a clean and assimilable pathway as L-citrulline allows us to restore the raw material to the body that stress and the passage of time take away. In the end, understanding how we function on the inside shows us that taking care of our blood vessels on a daily basis is the most practical way to protect the quality of our sex life in the long term.
Bibliography
- Cormio, L., De Siati, M., Lorusso, F., Selvaggio, O., Mirabella, L., Sanguedolce, F., & Carrieri, G. (2011). Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction. Urology, 77(1), 119-122.
- Shirai, M., et al. (2018). Oral L-citrulline and Transresveratrol Supplementation Improves Erectile Function in Men With Mild Erectile Dysfunction: A Randomized, Double-Blind, Placebo-Controlled, Crossover Pilot Study. Sexual Medicine, 6(4), 291-296.
- Agarwal, U., Didelija, I. C., Yuan, Y., Wang, X., & Marini, J. C. (2020). Therapeutic potential of citrulline as an arginine supplement: a clinical pharmacology review. Paediatric Drugs, 22(3), 279-293.
About the author
Content researched and written by the Anastore editorial team.
Reviewed and verified against scientific literature by our Nutrition and Research Department.
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This article is strictly for informational purposes and does not replace the advice of a healthcare professional.