Arginine is a type of amino acid that makes up protein. Because it is commonly included in male vitality supplements, it is often labeled as a “men’s supplement.” However, contrary to many advertisements, arginine is a nutrient that benefits both men and women.

Arginine helps improve blood circulation, supports blood sugar control, and plays an important role in increasing muscle strength. Let’s take a closer look at arginine — a versatile supplement known to support overall health, including blood pressure, blood sugar, and muscle function.

WHAT: A Type of Amino Acid That Makes Up Protein

Harder for the body to synthesize when you’re not in good condition

Arginine is classified as a non-essential amino acid, meaning the body can normally produce it on its own. However, “non-essential” does not mean unimportant.

The human body requires 21 amino acids in total. Of these, 9 are essential amino acids that must be obtained from food because the body cannot synthesize them. The remaining amino acids, including arginine, are considered non-essential because the body can produce them.

The issue is that when the body is under stress, fatigued, or not functioning optimally, its ability to synthesize arginine may decline. In addition, arginine has relatively low absorption efficiency when consumed through food alone. For people who frequently feel tired or run down, supplementation may help fill this gap.

Is Arginine Different from L-Arginine?

In short, no — they are the same.

Amino acids can exist in two mirror-image forms, known as chirality. These are called the L-form and the D-form. While they have the same molecular components, their structures differ, like a reflection in a mirror.

Arginine, like most amino acids, exists in both L-arginine and D-arginine forms. However, of the 20 amino acids used by the human body (excluding glycine), 19 are in the L-form. That is why when people refer to “arginine,” they are almost always referring to L-arginine.

In other words, “arginine” is simply a shortened name — its proper form used by the body is L-arginine.

EFFECT: Supports Muscle Growth and Liver Function

Arginine plays several important roles in the body.

First, it helps produce nitric oxide (NO). Nitric oxide relaxes and widens blood vessels, improving blood flow. This improved circulation supports muscle growth and is one reason arginine is associated with enhanced physical performance and vitality.

Second, arginine supports the liver’s urea cycle. One of the liver’s key functions is converting ammonia — a toxic metabolic byproduct — into urea so it can be safely excreted in urine. If ammonia accumulates in the body, it can lead to chronic fatigue and liver-related issues.

Arginine accelerates this conversion process, helping the liver function more efficiently and reducing fatigue. Animal studies have shown improvements in liver function following arginine supplementation.

Finally, arginine stimulates insulin secretion, which can help regulate blood sugar levels. It also enhances mitochondrial activity, increasing basal metabolic rate and supporting fat breakdown.

HOW TO: Because absorption is low, supplements are often more effective than food

Look for these supportive ingredients

Arginine is found in red meat, fish, dairy products, eggs, lentils, and chickpeas, and it is also produced naturally in the body. However, due to its low absorption rate, many experts recommend supplementing rather than relying solely on dietary sources.

When choosing an arginine supplement, it is important to check whether it contains ingredients that enhance absorption.

One highly recommended supporting ingredient is ornithine hydrochloride. Ornithine is an amino acid involved in the urea cycle, helping remove ammonia from the body. When taken together with arginine, it creates a synergistic effect that improves metabolism and increases overall absorption.

Who Should Avoid Arginine?

Even beneficial supplements are not suitable for everyone.

• People with low blood pressure should avoid arginine, as it may further lower blood pressure.
• Older adults, especially those with a history of heart attack, should use caution or avoid arginine altogether.
• Individuals with kidney issues or gout should avoid arginine, as protein metabolism produces waste products that must be excreted through the kidneys.
• People with herpes (cold sores) should not take arginine, as the herpes virus uses arginine to replicate.

Best Taken on an Empty Stomach — Use Caution If You Have a Sensitive Stomach

Arginine is best absorbed when taken on an empty stomach. However, people with sensitive digestive systems may experience stomach discomfort.

If gastrointestinal issues occur, it is recommended to:

• Reduce the dosage
• Avoid taking it on a completely empty stomach
• Switch from capsules to liquid form

Liquid arginine supplements are typically taken once daily (100 mL), either on their own or mixed with half a cup of water. If discomfort persists despite these adjustments, supplementation should be discontinued.

Source: KB의 생각[KB 금융그룹] (https://kbthink.com/)