Affiliate Disclosure
blood and heart health image for l-arginine guide

L-Arginine Guide (+ Top 3 Supplements)

L-arginine is an amino acid produced by the body and derived from foods. It has been popularized as a supplement in the past few decades as a way to boost cardiovascular and fertility. But does the research back the hype?

In this guide, we’ve laid out the best l-arginine supplements. Farther down, we’ve summarized the research on l-arginine’s benefits and common dosages.

Top 3 L-Arginine Supplements

Best L-Arginine Supplement Overall

NOW Supplements – Pure L-Arginine Capsules


Pure l-arginine

Easy to take

No flavor

per capsule

This is the go-to l-arginine supplement. NOW Foods is a reputable health supplement brand, and this pick is no different. It’s one of the most popular and highly-reviewed l-arginine supplements on Amazon.

Best Value L-Arginine Supplement

BulkSupplements – Pure L-Arginine Powder (1 kg)

Pure l-arginine powder

Best value

Available in bulk

If you’re looking for the most bang for your buck, this is it. This pure l-arginine powder is available in bulk, making it one of the most inexpensive options per serving.

Best L-Arginine Cream

Preventix – Magnesium L-Arginine Cream

Easy absorption


No fragrance

Some people prefer to apply l-arginine topically, and this l-arginine cream does just the trick. It’s made with magnesium harvested from the Dead Sea to support healthy skin. It’s soothing to the skin and scent-free.

L-Arginine Benefits

Studies have found correlations between l-arginine supplementation benefits like reduced blood pressure and improve fertility. We’ve summarized the research below.

  • L-Arginine Blood Pressure Effects

Research has shown that l-arginine may be effective in lowering blood pressure.

In the early 1990s, it was discovered that taking l-arginine leads to increased production of nitric oxide inside the blood vessels.1The L-Arginine-Nitric Oxide Pathway Nitric oxide, in turn, causes vascular tissue (such as veins and arteries) to relax.2Vascular endothelial cells synthesize nitric oxide from L-arginine This process alone indicates that l-arginine may have an impact on blood pressure.

One study examined the cardiovascular effects of l-arginine on fifteen patients with sepsis syndrome, a condition characterized by inflammation following extreme infection.3L-arginine pathway in the sepsis syndrome. When each group was administered l-arginine, researchers noted a short-term decrease in blood pressure. They also noted an increase in cardiac output, the measure of blood volume pumped in liters per minute.

Another study demonstrated the mechanisms by which l-arginine reduces blood platelet aggregation.4An L-arginine/nitric oxide pathway present in human platelets regulates aggregation In plain English, the study indicates that l-arginine may help reduce the risk of blood clots by inhibiting certain blood-clotting mechanisms.

  • Immune System Support

Research has shown that l-arginine supplementation can support T cell function.5Regulation of immune responses by L-arginine metabolism T cells are a type of white blood cell that play a role in the immune system. The cited study shows that supplementing l-arginine may lead to an increase in immune system function.

  • L-Arginine Fertility Improvement

One study sought to examine the effects of l-arginine and pycnogenol in men with mild erectile dysfunction and low sperm count and motility.6Improvement of seminal quality and sexual function of men with oligoasthenoteratozoospermia syndrome following supplementation with L-arginine and Pycnogenol® At two months of treatment, the researchers measured significantly increased sperm concentration. They also noted a significant reduction in erectile dysfunction.

  • L-Arginine Weight Loss Impact

One study performed on pigs provides some promising insight into l-arginine’s weight loss effects.7Dietary l-arginine supplementation increases muscle gain and reduces body fat mass in growing-finishing pigs The study found that after 60 days of supplementation, pigs that were given l-arginine demonstrated a 5.5% increase in muscle mass and an 11% decrease in fat mass compared to a control. These findings indicate that l-arginine may be effective in promoting weight loss (specifically, fat loss).

Unfortunately, we need more human studies on l-arginine and weight loss. Further research is needed before we can know with more certainty whether l-arginine may be effective for weight loss.

L-Arginine and Pycnogenol

Several studies have demonstrated that l-arginine and pycnogenol may be effective reducing erectile dysfunction and improving fertility.

L-arginine and pycnogenol together have been studied as a means to affect erectile dysfunction.8Treatment of Erectile Dysfunction with Pycnogenol and L-arginine Proper erectile function is supported by nitric oxide, which can be increased by both l-arginine and pycnogenol individually. The study found that supplementing l-arginine and pycnogenol together may significantly improve sexual function in men with erectile dysfunction.

A slew of other studies have similarly found that supplementing l-arginine and pycnogenol together may be effective in men with mild to moderate erectile dysfunction.9Clinical Assessment of a Supplement of Pycnogenol® and l‐arginine in Japanese Patients with Mild to Moderate Erectile Dysfunction

As mentioned above, one study found that l-arginine and pycnogenol together may improve sperm count.10Improvement of seminal quality and sexual function of men with oligoasthenoteratozoospermia syndrome following supplementation with L-arginine and Pycnogenol The study noted a significant improvement in sperm concentration and erectile function after two months of supplementation.

For more information on pycnogenol, refer to our complete pycnogenol guide.

Nitric Charge: L-Arginine, Citrulline, and Pine Bark Extract

This is a top-notch blend of l-arginine, citrulline, and pine bark extract (which is similar in composition to pycnogenol).



Pine bark extract

L-Arginine and Alpha-Ketoglutarate

L-arginine and alpha-ketoglutarate are sometimes marketed as fitness and/or athletic performance enhancers, but there is currently not enough evidence to support this. One study did find that l-arginine and alpha-ketoglutarate supplementation resulted increased bench press one-rep-max.11Pharmacokinetics, safety, and effects on exercise performance of l-arginine α-ketoglutarate in trained adult men However, other research has found no impact of l-arginine and alpha-ketoglutarate on muscle performance or cardiovascular condition.12Acute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained men13Effects of 7 Days of Arginine-Alpha-Ketoglutarate Supplementation on Blood Flow, Plasma L-Arginine, Nitric Oxide Metabolites, and Asymmetric Dimethyl Arginine After Resistance Exercise

L-Arginine and L-Citrulline

One study looked at the effects of pycnogenol, l-arginine, and l-citrulline on sperm quality.14Sperm quality in men is improved by supplementation with a combination of L-arginine, L-citrullin, roburins and Pycnogenol®. The study examined the effects of these substances on 50 men with poor sperm quality over one month of supplementation. At the end of the trial, sperm volume, concentration, motility, and vitality were significantly improve compared to placebo. These findings indicate that l-arginine and l-citrulline together with pycnogenol may be effective in improving sperm quality.

Havasu - L-Arginine and L-Citrulline

Each twp-capsule dose contains a 400 milligrams of l-arginine and l-citrulline each. Perfect for taking both supplements together.



Beet root powder

L-Arginine Dosage

There is currently no officially recommended l-arginine dosage.

Some of the above-cited research used an l-arginine dosage of roughly 700 milligrams daily. Many users take up to 2 or 3 grams daily with no notable side effects, but little research has been performed on doses that high.


Research has shown that l-arginine may be effective in improving a handful of health factors, including blood pressure and fertility. In particular, studies have shown l-arginine and pycnogenol together can be effective in improve fertility and erectile function.

For further reading, our complete pycnogenol guide details a slew of research-backed health benefits of the ancient Indian herb, including cardiovascular, skin, and brain support.

TOP PICK: Pure L-Arginine Capsules

Pure l-arginine

Easy to take

No flavor

More for You

Stall Bars Guide
Stall Bars / Swedish Ladders: 2019 Guide & Reviews
Stall bars (also called wall bars, stall walls, Swedish ladders, and Swedish walls) are pieces of gymnastics equipment featured in
Read more.
Best Kava Brands Guide
Kava Guide + Top 6 Picks (Summer 2019)
Kava is a shrub that grows in the Pacific Islands. For centuries, its roots have been ground into a powder
Read more.
Best Black Seed Oil Guide
Best Black Seed Oil Brands (Summer 2019)
Black seed oil is an increasingly popular health supplement. It’s an extract used in Middle Eastern and South Asian medicine
Read more.
Best MCT Oil Brand
Best MCT Oil Brands (Summer 2019)
MCT oil is an increasingly popular health supplement. It’s great for supporting ketosis, and research indicates it may benefit weight
Read more.
gluten free protein shakes
Best Gluten-Free Protein Powders (Summer 2019)
When you’re looking for gluten-free protein powder, it can be annoying to slough through descriptions. To speed up the process,
Read more.
blood and heart health image for l-arginine guide
L-Arginine Guide (+ Top 3 Supplements)
L-arginine is an amino acid produced by the body and derived from foods. It has been popularized as a supplement
Read more.
image of brain for l-serine guide
L-Serine Guide (+ Top 3 Supplements)
L-serine is an amino acid that plays a role in the function of the nervous system, including the brain. It’s
Read more.
collage of pine bark, hands applying lotion, and brain illustration
Pycnogenol Guide (+ Top 5 Brands)
Pycnogenol is an extract from the bark of the French maritime pine tree. First developed in 1947, this woodsy supplement
Read more.
a man meditation at sunset and a rhodiola herb
Rhodiola Guide (+ 7 Top Picks)
Rhodiola rosea is an herb that grows in arctic and mountainous regions of Europe and Asia. Its roots have been
Read more.
an illustration of ashwagandha next to a silhouette of a person meditating
Ashwagandha Guide (+ 7 Top Brands)
Ashwagandha is an ancient medicinal herb used by Ayurvedic physicians of India for thousands of years. Today, it’s often taken
Read more.
Collage of vegan foods and vegan protein shakes
Best Vegan Protein Powders (Summer 2019)
Getting enough protein on a vegan diet isn’t always a piece of cake. (We’re talking vegan cake, of course.) So
Read more.
Chocolate paleo protein powder
Best Paleo Protein Powders (Summer 2019)
The paleo diet, praised as a holistic return to our ancestor’s dietary roots, has grown in popularity since the early
Read more.