Citrulline - what it is, effects, dosage, when to take + opinions

Citrulline is a popular supplement among athletes that gets you pumped up on a workout: veins like cables and +50 to motivation. I've collected previous work from researchers who took subjects and tested whether they could actually do more and last longer with citrulline - in the gym, on the bike or in the... bedroom.

I prepared this article together with nutritionist Kuba Pągowski. Learn all about the properties of citrulline - you may find it will be a cool supplement for you, unless... you prefer to cut into watermelon. Lots of watermelons. But about that in a moment...

See also:

• Creatine
• L-carnitine
• Caffeine
• Arginine
• Whey protein concentrate (WPC)
.
• Whey protein isolate (WPI)
.
• Whey protein hydrolysate (WPI)
.
• Vegetable protein
• Protein nutrient
• BCAA

Citrulline - what is it?

Citrulline is a non-protein amino acid that the body produces naturally, but can also be found in food. It is included in many nutritional supplements for active people for its properties of increasing blood flow, reducing fatigue and achiness and lowering blood pressureand.

The name comes from the Latin citrullus meaning 'watermelon'. - because it is this fruit that is its richest sourceand.

Citrulline has several functions in the body, including and:

• takes part in the urea cycle,
.
• produces another important amino acid, arginine,
.
• increases blood flow in the circulatory system,
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• expands blood vessels,
.

Dietary supplements with citrulline are popular with active people, especially those training at the gym. Manufacturers offer preparations with citrulline in two forms:

• Citrulline malate  - a combination of l-citrulline and an ionised form of malic acid naturally found in fruit,
.
• L-citrulline - which is simply pure citrulline.

Both forms can produce similar effects, but it is citrulline malate that is more common in sports supplements. Interestingly, when using citrulline malate, it is not clear which health effects are due to citrulline and which are due to malateand.

How does citrulline work?

Citrulline works by converting into arginine, an amino acid that then stimulates the production of nitric oxide. This is a key neurotransmitter that helps to dilate blood vessel walls -a process called vasodilationand.

Through this action, citrulline:

• improves blood flow, allowing blood to move more freely, resulting in more efficient transport of oxygen and nutrients to organs and tissues ,
.
• lowers blood pressure, which is particularly important for those suffering from hypertension or who are predisposed to heart disease ,
• benefits muscle performance during exercise .

Can you say: if arginine is so cool, maybe it's better to supplement with it, instead of citrulline? Research suggests that consuming dietary supplements with citrulline may increase arginine levels in the body more than consuming arginine aloneand.

Is citrulline a steroid?

No, citrulline is not an anabolic steroid because, unlike synthetic versions of sex hormones, it does not affect protein synthesis and has no direct effect on muscle development . Citrulline is a safe and well-studied amino acid.

Citrulline is also a precursor to the body's production of nitric oxide (NO), which plays a role in dilating blood vessels and improving blood flow, so it is often used as a pre-workout supplement to enhance physical performance , but has nothing to do with so-called doping.

Is citrulline safe?

Yes, citrulline is safe to use. In research studies, taking up to 15g of citrulline per day had no side effectsand. Citrulline is a well-studied amino acid, and when used according to the manufacturer's recommendations, it should not harm you.

Properties of citrulline

According to scientific studies, citrulline has been shown to support training performance and post-exercise muscle recovery, has a positive effect on blood vessels, can reduce blood pressure (by up to 15%), and may be helpful in erectile dysfunctionand.

Citrulline was isolated in 1914 and has since attracted the interest of scientists, who have been 'under the magnifying glass' and with human participants to test the interesting properties of this amino acid .

Research to date suggests that citrulline:

Increases muscle pump

Call the power station, someone has solid cables to connect!"

Let's not kid ourselves - a good pump motivates performance. It is created when nitric oxide acts on the muscles, dilates the blood vessels and increases blood flow to the muscles. This makes them swollen and the veins on the arms more visible. The effect lasts for up to tens of minutesand.

Through its properties, citrulline contributes to the formation of arginine, which implies the production of nitric oxide (NO)and. The consequence of this is improved blood flow and therefore faster delivery of the substance to the muscles.

Well, and those cables.

Reduces fatigue during training

Citrulline can help you exercise for longer and survive the last series of your workout when you are already tired. Researchers interviewed several study groups to confirm this beneficial effect.

In a 2015 study, strength-trained men were divided into two groups. One received 8g of pure (99%) citrulline malate, the other a placebo. They performed five sets each of leg press, machine squat and leg raise. The men taking citrulline malate performed more repetitions during all exercises compared to the placebo groupand.

In a 2016 study, a group of 22 trained cyclists took 2.4 g/day of L-citrulline or placebo for 7 days. On day 8, they took 2.4 g of L-cytrulline or placebo 1 hour before a 4km time trial on the bike. In the 'citrulline' group, it reduced the time it took to complete the exercise test and lowered the subjective feeling of muscle fatigue after exerciseand.

Reduces muscle soreness after exercise

A good workout can follow you for several days. You can feel its effects even just walking down the stairs from the gym - it's just fatigue and soreness.

When you do a strong workout, your muscles work so hard that the circulation is unable to supply them with enough oxygen. This is when they start to produce lactateand.

Lactate has a bad reputation as the 'culprit' of muscle pain and fatigue. However, its production is a natural mechanism that tells you when your body has reached its limits and needs rest.

In a 2017 study, a group of men were given either a placebo or a watermelon drink enriched with L-cytrulline (3.45 g in 500 ml). After two hours, they ran a half marathon (21 km). The men drinking the juice reported less muscle soreness from 24 to 72 hours after the race, and their bodies maintained lower plasma lactate concentrations.

Influences on growth hormone (GH)

Growth hormone (GH, pronounced  growth hormone) plays an important role in tissue (e.g. muscle) regeneration and recovery, which is particularly important for those who train regularly.

Citrulline is one of the better growth hormone boosters. A 2010 study involved two groups of experienced cyclists. One group received a placebo and the other 6g of citrulline malate before starting a 137km bike ride.

The supplemented group had a 67% higher growth hormone output. The increased GH is linked to citrulline's effect on better amino acid utilisation and activation of pathways affecting its ejectionand - i.e. better tissue regeneration and restoration.

Reduces blood pressure

Citrulline is helpful in lowering blood pressure. This happens under the influence of nitric oxide, which dilates blood vessels and improves blood flowand.

A 2015 study analysed the effects of citrulline supplementation on 43 obese postmenopausal women. They were divided into 3 groups and tookand:

• L-cytrulline (6 g),
.
• L-cytrulline (6 g) and trained WBVT (vibration training),
.
• placebo and trained with WBVT.

L-cytrulline or l-cytrulline combined with vibration training lowered blood pressure in the women studiedand.

In 2016, a group of 12 young men were given 3g of citrulline daily and after just one week, their blood pressure dropped by 6-16% .

What is important: it is not clear whether citrulline has a significant effect on blood pressure in healthy individuals .

Erectile enhancement

Citrulline with arginine can be found in many erection tablets available over-the-counter. Let me stress right away that citrulline will not cure erectile dysfunction, but in some men it may prove supportive therapy.

In a 2011 study, a group of 24 men with erectile dysfunction were given either a placebo or 1.5g of citrulline daily for one month. Before and after supplementation, the men rated penis hardness on a dedicated scale and indicated the number of sexual intercourses per monthand.

After one month of supplementation:

• the hardness rating of the penis increased from 3 to 4 in 50% of subjects using citrulline and in 8% of subjects in the placebo group,
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• the number of intercourses increased in both groups,
.

Another 2018 study tested the efficacy of taking L-citrulline and transresveratrol in 13 patients with erectile dysfunction who are using concomitant medications for the disorderand.

The researchers concluded that additional supplementation of citrulline and trans-resveratrol may support erectile dysfunction treatment therapy. Importantly, the addition of these compounds to therapy does not cause side effectsand.

Care for endothelial health

The vascular endothelium is the single layer of cells between the lumen of the vessel and the smooth muscle cells of the vessels, explains nutritionist Kuba Pągowski.

Citrulline, through its positive effect on the endothelium, reduces the risk of hypertension and other cardiovascular conditions, type 2 diabetes, and many diseases underlying endothelial dysfunctionand.

Increases endurance

Recent research suggests that citrulline supplementation may indirectly improve exercise performance through various mechanisms - nitric oxide synthesis, ammonia buffering, increased oxygen delivery and energy production .

In research studies with athletes on improving endurance, blends of citrulline with other compounds worked best . Citrulline solo is not the best supplement typically for improving endurance. It can support it indirectly, but if you are endurance training, for example, beta-alanine would be a more apt choice .

How does citrulline not work?

When taking citrulline, it's worth knowing what effects to ... not expect. There are various opinions circulating about it among athletes ("it stimulates me"), and supplement manufacturers bend reality in their product descriptions ("giga concentration, giga erection").

Citrulline is not a good product.

Citrulline: