If you want to boost your fitness, check out L-arginine and L-citrulline. These two amino acids are often used in dietary supplements to stimulate the body’s functions. 

Both target the production of nitrous oxide, which helps relax blood vessels throughout the body, increasing circulation and heart health. These changes can help improve a few of the body’s functions: 

  • Athletic performance
  • Heart health
  • Blood pressure 
  • Sexual performance

Supplementing L-citrulline and L-arginine can help keep you healthy. However, since they complete similar tasks, you may wonder which is better. Contrary to popular opinion, you may not have to pick one over the other. 

This article will explore all the best parts of L-citrulline and L-arginine and help determine which supplement fits you best. 

How Amino Acids Work

Amino acids are critical to your body’s functions, but many don’t grasp how they work. These acids are the building blocks of proteins, which help develop and maintain tissues throughout your body. 

When you consume proteins, your body will break them down into amino acids, which will help carry out various functions. Amino acids are critical for much, from muscle-building to immune function.

What Makes an Amino Acid “Essential”

When talking about proteins, you may hear the term ‘essential’ amino acids. These are a group of nine amino acids that can’t be synthesized by the body, meaning you’ll have to get them through your diet. The nine essential amino acids are:

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

You’ll notice that L-arginine and L-citrulline are absent from the list, meaning they’re present in your body. You can still increase their benefits by supplementing.

L-Citrulline vs. L-Arginine

L-Arginine vs. L-Citrulline 

L-arginine and L-citrulline help the body but often get lumped together. Let’s explore their distinctive differences. 

What is L-citrulline?

L-citrulline is a non-essential amino acid produced in the body during the urea cycle. It is also present in many foods, like watermelons, cucumbers, and pumpkins. 

Due to recent discoveries, L-citrulline is offered in many supplemental forms, from pills to powders. 

L-citrulline Benefits 

L-citrulline has recently gained popularity due to a few prime health benefits. This amino acid increases nitric oxide production in the body, which helps widen blood vessels and improves heart health and circulation. 

The increased nitrous oxide will lower blood pressure, allowing increased exercise performance. With a sufficient amount, you’ll find increased activity capabilities and less soreness. 

What is L-arginine?

L-arginine is another non-essential amino acid found throughout your body. It is also found in many protein-rich foods, like fish, poultry, green beans, soy, whole grains, and dairy products. 

Like L-citrulline, this supplement is now offered heavily throughout the fitness world. Athletes are using it to maximize their body and help performance recovery. 

L-arginine Benefits

Though L-arginine is similar to L-citrulline, it offers significant benefits. Like its counterpart, L-arginine boosts nitrous oxide production throughout the body. This amino acid encourages blood flow and circulation by relaxing and widening blood vessels. 

The increased blood flow may help stop erectile dysfunction. 

Furthermore, studies suggest L-arginine can improve immune systems, especially those which may be compromised. 

Running Fitness Workout

Differences Between L-Arginine vs. L-Citrulline

If you’re thinking of supplementing these two compounds, you may wonder which is better. After all, these amino acids complete similar functions throughout the body, both increasing nitrous oxide. 

While the research isn’t finalized, early studies show that L-citrulline may be more effective than its counterpart. This amino acid produces more nitrous oxide, which increases the benefits throughout the body. This doesn’t necessarily mean you should stop L-arginine altogether.

Can I Take Them Together?

Though L-Citrulline has more pronounced effects than its partner, you may get the most out of taking them together. Research shows that the two compounds can have a more substantial impact by promoting one another. 

Side Effects of L-Citrulline and L-Arginine

We recommend talking to your doctor before starting any supplement, especially if you’re on anything that affects your blood pressure.

While L-arginine and L-citrulline are generally safe, there are specific side effects associated with their use. Both can cause effects of gastrointestinal distress. After taking, watch for any side effects, including:

  • Nausea
  • Bloating
  • Headache
  • Allergies 
  • Gout 

If symptoms persist, stop taking your supplements. L-arginine may also interact with medications, such as nitrates for angina or erectile dysfunction. Conduct proper research before you begin. 

Keep your Health High with Ultimate Nutrition

Exercise and healthy eating aren’t the only ways of boosting your body. Supplements can provide benefits for your energy, weight, and beyond. While you contain many non-essential amino acids, you can still find many uses in supplementing them. 

L-arginine and L-citrulline are two amino acids that help encourage nitrous oxide production. This process lowers overall blood pressure, which supports heart health and circulation, and can even help with certain medical conditions like angina and erectile dysfunction. While L-citrulline is shown to be more effective, pairing the two can help get the maximum benefit. 

Follow Ultimate Nutrition for all the best in supplementing. We’ll show you how to maximize your world, from our Protein Powders to our Weight Gainers. Even further, our articles will keep you up to date on the latest fitness and supplementing trends. Learn all about BCAA’s and what Creatine can do for your workout. 

Don’t fall short on your body– you deserve all the benefits supplementing can give you. 

Brian Rubino
Tagged: Supplements


Yes, I really wantnto fire 🔥 up my wngine with that nitrous oxide ( N.O) lol

— Michael Walsh

I have to agree with Jeb Dominick. Good catch.

— Edward Morton

I would never trust a web site owned by people who don’t know the difference between nitrous oxide and nitric oxide. You refer to your team of expert scientists. I don’t think so.

— Jeb Dominick

Want to buy ned to know where and dosage

— Bobby weiss