L-arginine is an amino acid that plays a key role in your body’s regulation of blood flow because of its ability to increase nitric oxide production. It’s also found in many pre-workout mixes, and it can help enhance both physical and sexual performance.
L-arginine has been used effectively for everything from improving heart function to increasing memory to treating erectile dysfunction. Since the function of pretty much everything in your body depends critically on its blood supply, this is no small matter.
Here’s our research-backed rankings of the ten best L-arginine supplements on the market.
1. L-Arginine PURE
L-Arginine PURE delivers a high dose of L-arginine, and it does so with a highly pure formulation with multiple forms of L-arginine.
Most of its 700 mg of L-arginine per capsule is delivered as arginine alpha-ketoglutarate, but it also includes small amounts of free L-arginine, L-arginine L-pyroglutamate, and L-arginine HCL.
Since these are absorbed through slightly different pathways in your body, this might boost absorption and lead to arginine levels that increase rapidly and stay elevated for a long time. This makes it great for boosting your sex drive and for athletic performance.
2. Roam Nitric Oxide
When it comes to raising your nitric oxide production through L-arginine, Roam Nitric Oxide is the best solution.
It provides two sources of L-arginine, both the HCL form and the alpha-ketoglutarate form, as well as citrulline to aid and assist with nitric oxide production. There are no extraneous ingredients, and the only downside is that the capsule is gelatin, so not fit for strict vegetarians.
3. Sheer Strength Sheer NO
Sheer NO is a supplement that focuses on boosting nitric oxide through a variety of ingredients, but L-arginine is one of the key constituents.
It’s accompanied by pine bark extract and citrulline, so as far as supplements that will boost nitric oxide production, it’s one of the better ones. However, its L-arginine content is only middle of the road due to the other ingredients.
4. Havasu Nutrition L-Arginine
Havasu’s L-arginine supplement delivers 400 mg of arginine per capsule, split between L-arginine HCL and L-arginine alpha-ketoglutarate.
In addition, it provides the companion amino acid citrulline, which is also linked to nitric oxide production in the body, and beet root extract, which further enhances nitric oxide production. If you are looking for maximal blood flow, it’s a great solution.
5. BulkSupplements L-Arginine Base Powder
For the true do it yourselfer, BulkSupplements L-arginine is the way to go. Coming in a pure powdered form of L-arginine HCL (which is what the “base” in the name refers to), this is what you want if you are looking for a way to incorporate L-arginine into your shakes or smoothies.
The downside is shared with all powder-based supplements that are usually taken in low doses: you’ll need a milligram-accurate scale to measure out doses.
6. Jarrow Formulas Arginine-Citrulline Sustain
Jarrow Formulas never goes for flashy supplement formulations, but they do simple formulas quite well. This is the case with their L-arginine supplement, which is a combo of L-arginine and citrulline malate a vegetarian capsule.
It’s certified free of common allergens like gluten, soy, dairy, shellfish, and eggs, making it a good choice for people with food sensitivities and allergies.
7. NOW Double Strength L-Arginine
NOW delivers a heavy dose of L-arginine, with 1000 mg of L-arginine HCL per capsule.
Unfortunately, it’s got a few more binders and stabilizers than purists might like, and another disadvantage is the fact that the L-arginine is supplied in just one form as opposed to multiple different forms.
Still, for those looking for high L-arginine dosages, it’s a good buy.
8. L-Arginine PRO Powder
This powder-based L-arginine supplement is something a little different–it’s almost more of a sports drink than just a supplement. It provides a very high dose (5500 mg) of L-arginine, alongside vitamins C, D, K, and several B-vitamins.
It’s flavored with stevia along with the artificial sweetener xylitol, which some people may not like. The taste and flavoring might make it a little too overpowering to add to a smoothie or a protein shake, which limits its versatility.
9. Amazing Formulas L-Arginine
At 1000 mg per capsule, Amazing Formulas has a high-potency L-arginine supplement, but aside from that, there is not a whole lot going for this supplement.
With several additional binders, the L-arginine comes only in an L-arginine HCL form. Perhaps better than free L-arginine, but not up to the standards of some of the top ranked supplements.
10. Bestvite L-Arginine
The L-arginine supplement from Bestvite is high dosage and no frills. It comes in the “free” form, which is cheap to manufacture but may not be as readily absorbed by your body as an alpha-ketoglutarate or even an HCL form of L-arginine.
Further, the capsule is stabilized by a lot of binders and fillers, which are a bit of a turn-off. The 1000 mg dosage is the one upside to this L-arginine supplement.
Best L-arginine overall: Pure Label L-Arginine
Delivering a potent and highly bioavailable dose of L-arginine, Pure Label is our overall winner thanks to its clean supplement design and delivery. If you’re looking for the best arginine-only supplement out there, choose Pure Label L-Arginine.
Best L-arginine for erectile dysfunction and sexual performance: Roam Nitric Oxide
If you are unhappy with your sexual performance, low levels of nitric oxide might be to blame. Roam Nitric Oxide boosts arousal and erectile function thanks to its multi-ingredient approach to up-regulating your body’s production.
Best L-arginine for heart health and blood pressure: Pure Label L-Arginine
For heart health, you want to keep things simple: Pure Label L-Arginine delivers over 700 mg of L-arginine per capsule, split across three different forms for maximum absorption. If you’re looking to emulate research that’s used L-arginine to control blood pressure, Pure Label is the way to go.
Best L-arginine for working out: Sheer Strength Sheer NO
Sheer Strength designed this supplement specifically to boost strength and endurance via L-arginine. You get a hefty dose of L-arginine alongside citrulline malate and pine bark extract, plus no extraneous binders or fillers. It’s perfect for setting personal bests at the gym.
Best L-arginine for weight loss: Havasu Nutrition L-Arginine
Havasu Nutrition L-Arginine pairs the nitric oxide boosting capabilities of L-arginine with widely-known nitric oxide boosters found in beet root extract. These ingredients interact to improve your body’s ability to process carbs, which is a huge help when trying to lose weight.
Best L-arginine for boosting nitric oxide: Roam Nitric Oxide
Roam Nitric Oxide includes two forms of L-arginine alongside citrulline malate to accelerate your body’s nitric oxide production. This makes Roam a great choice whether your goals are athletic performance or sexual performance.
Who should buy L-arginine?
L-arginine has three primary uses: improving workout performance and recovery, improving cardiovascular health, and improving sexual wellness, particularly in men.
On the performance front, L-arginine helps your body produce nitric oxide, which increases blood supply to your muscles by dilating your blood vessels. In addition, it shifts your carbohydrate metabolism so that your body can replenish muscle glycogen more readily following an intense workout.
Some research suggests that L-arginine can can also increase maximum anaerobic power production and one-rep max, probably by increasing muscular function.
On the health front, L-arginine helps decrease blood pressure by the same nitric oxide upregulation mechanism that boosts performance.
This could help lower risk for cardiovascular disease, but that’s not the only heart health benefit of arginine. It also helps improve your body’s ability to process carbohydrates, which becomes impaired in metabolic syndrome and in people who are overweight or obese, and is an independent risk factor for heart disease.
Since L-arginine modulates nitric oxide production, it’s also been used successfully as a treatment for erectile dysfunction. Some (though not all) cases of erectile dysfunction can be linked to a deficit of nitric oxide levels, and L-arginine appears to help in these cases.
So, through a few similar mechanisms, L-arginine is useful for people who want to improve their fitness, their athletic performance, and their sexual health.
Additionally, it also can help people who are looking to decrease their risk factors for heart disease.
How we ranked
When it comes to L-arginine, efficacy and dosage are king. We examined L-arginine supplements as well as nitric oxide supplements that used L-arginine in a central role alongside other compounds like citrulline to increase nitric oxide levels.
We looked at both categories because people looking to follow the scientific research as closely as possible likely want pure, unadulterated L-arginine, but people who take a more holistic approach to supplementation may want to take advantage of synergies between L-arginine and other ingredients involved in the synthesis of nitric oxide in the body.
A number of related compounds are used in the biological pathway that L-arginine activates, and supplying these compounds alongside L-arginine may well increase the efficacy of a given dose of L-arginine.
When analyzing pure arginine supplements, we put a high priority on purity. Any additional ingredients, even binders or bulking agents, detracted from our ratings, and many supplements didn’t even make our list because they were so crowded with unnecessary ingredients.
A clean and streamlined supplement design informed our ratings of the L-arginine based nitric oxide supplements. We required that the more holistic supplement design not compromise the L-arginine dosage, and dropped anything that didn’t deliver an adequate amount of L-arginine (enough to be effective based on clinical research using L-arginine only).
Next, we checked to see if the other ingredients provided alongside L-arginine had strong scientific evidence supporting their efficacy. If not, we eliminated that supplement from our rankings—a nitric supplement that provides useless ingredients is no better than a basic L-arginine supplement, and is less pure.
The products that made the final cut represent the best of both pure L-arginine products and nitric oxide supplements that provide a hefty and efficacious dose of L-arginine.
L-arginine is an amino acid and is considered to be one of the essential building blocks of protein. It is most commonly used by trainers and fitness experts as a dietary supplement in an attempt to induce training performance, particularly with regards to gaining higher energy and overcoming muscle fatigue.
The benefits of l-arginine largely relate to the increase in the concentration of nitric oxide, which is a compound developed by the endothelium of the blood vessels that is known for expanding blood vessels.
Additionally, l-arginine is also used for improving cardiovascular health by dilating clogged arteries and increasing proper blood flow to the body.
Other uses for l-arginine include treating wounds, improve liver function, and foster an efficient number of hormones in the body. L-Arginine, or arginine, is developed naturally inside the human body.
As an amino acid, it becomes nitric oxide, which is then released into the bloodstream according to certain physiological changes, such as changes in blood pressure and cholesterol (1).
Arginine also signals your body to produce more protein, which has a considerable uses for gaining muscle and strength and for increasing sperm count.
More importantly, arginine also stimulates the growth of vital growth hormones along with glucose that enable you body to obtain the necessary nutrients for growth and higher energy.
This leads to a host of advantages that will be looked into greater detail.
There are various studies to show that l-arginine can help you gain muscle, boost male sexual health, and also improve cardiovascular health. As for muscle growth, a 2009 study (2) shows that l-arginine can lead to muscle growth and fat loss.
The study was experimented on 24 pigs over a 60 day period found tremendous results in overall weight loss and muscle development. Still, l-arginine shouldn’t be used as a stand-alone weight loss supplement.
Another study conducted by Zajac et.al (3) found that increases in l-arginine leads to an increase in growth hormone levels.
This has important results for bodybuilders and trainers who train to burn fat and achieve large muscle size. The l-arginine can lead to better protein synthesis and fat metabolism.
In addition, the release of nitric oxide provides a host of advantages in reducing recovery times in between training days to help overcome DOMS (delayed onset muscle soreness) and acute muscle soreness, which is why its found in many post workout drinks.
What this means is that you’re fatigued and sore muscles will be able to recover a lot faster and maximize your workout performance.
Secondly, l-arginine is also found to have important applications for fostering healthy sexual lives for both men and women. For men, it has the capacity to treat erectile dysfunction (4). Since it turns into nitric oxide, l-arginine can ensure healthy penile erection by expanding penis blood vessels and promoting proper blood flow. As a result, the penis can become stiff efficiently and remain erect for longer durations for engaging in sexual activities.
Increases in sperm count have also associated with a rise in l-arginine levels in the body. This offers a ray of hope to infertile men and gives them the opportunity to participate in healthy sexual activities.
Thirdly, l-arginine is also has been discovered to substantially improve cardiovascular health. By turning into nitric oxide, the amino acid eases clogged arteries and ensures health blood circulation.
This is also beneficial for alleviating chest pains and symptoms of coronary heart disease (5). However, the benefits of l-arginine on the heart are not conclusive; hence, it should be used on a case-by-case basis.
L-arginine can improve your body’s ability to refuel and repair after a tough workout. L-arginine is best known for its ability to dilate blood vessels and increase blood supply to muscles, which can account for its ability to improve athletic performance, but numerous studies have also noted that L-arginine altered carbohydrate metabolism in a beneficial way.
The supplement has found applications in improving metabolic function in people at risk for heart disease for this same reason, but a fascinating study conducted by researchers at the University of Texas at Austin suggests that athletes could take advantage of the same benefits (6).
The study involved twelve trained cyclists who completed hard training rides, then refueled with either a carb-only sports drink or a supplement that provided both carbohydrates and L-arginine.
The researchers found that when the cyclists refueled with a supplement that provided L-arginine in addition to carbohydrates, their rate of carb oxidation decreased following exercise, which they interpreted as a sign that more carbohydrates were being absorbed into the muscles as opposed to just being burned for energy.
These results indicate that recovery after a tough workout can be boosted if you consume L-arginine in addition to carbohydrates—your muscles can take better advantage of the available fuel in your system to replenish your muscle glycogen stores.
Although there are clear benefits to the function of l-arginine, there are also certain side-effects that need to be considered prior to use. This is why it is crucial that you consult your medical physician.
Heart patients need to be especially cautious prior to using any l-arginine supplements. There is research to support l-arginine, in fact, can lead to poor heart health.
A John Hopkins study concluded the l-arginine neither improves vascular stiff nor does it increase ejection fraction (7). The study also led to the death of 6 patients of the l-arginine which led the study being cancelled at an early stage.
There are also minor side effects associated with l-arginine that can be experienced as a result of overdose. Some of these side effects are nausea, diarrhea, and weakness in the body.
This is why it is important that you pay close attention to the type of diet you are following. We have already mentioned how l-arginine is found in many food sources. A diet rich in such foods along with l-arginine supplements can heighten the risks of an overdose.
For muscle building, l-arginine can boost your physical endurance levels and minimize recovery periods during and between workout days. If you have a medical condition, such as erectile dysfunction, impotence, or a heart disease, l-arginine can help you alleviate its symptoms. However, you should never hasten to use it without consulting your medical physician.
L-arginine doses in the scientific literature typically range from three to eight grams of L-arginine per day.
The higher end of the dosage range is typically reserved for clinical trials on people with heart disease or hypertension, while studies on sports and athletes in training use more middle-of-the-road doses, around five grams per day.
Some more sophisticated studies prescribe dosages based on body mass: a typical amount might be 0.08 grams of arginine per kg of body mass. So, an 80 kg athlete (176 pounds) would take 6.4 grams of L-arginine per day. This helps control for the fact that larger people have much more body mass and blood volume, so the same dosage of L-arginine will affect them to a lesser extent than a smaller person.
The research is less clear on how L-arginine should be spaced out throughout the day. Some studies use several divided doses, at different times during the day, but some have also had success with a single large dose of L-arginine all at once.
One thing we do know is that if you are using L-arginine to boost recovery after a tough training session or competition, you want to take L-arginine alongside one gram of carbohydrates per kilogram of body mass, and consume it as soon as possible finishing your workout.
This is the best way to optimize post-workout muscle glycogen recovery using L-arginine.
Q: What is L-arginine?
A: L-arginine, sometimes also known simply as arginine, is an amino acid that’s used as a building block for many different kinds of proteins in your body.
It can be found in protein-rich foods, both plant and animal-based, and it also plays an important role in regulating your body’s production of nitric oxide. Nitric oxide helps control blood supply by creating vasodilation, a relaxation of the blood vessels. This can increase blood flow and oxygen supply, which explains why L-arginine is a popular pre-workout supplement.
When your muscles get more oxygen during a workout, your ability to perform is improved. This same mechanism is also why L-arginine has been researched as a treatment for high blood pressure and for erectile dysfunction, which is linked to abnormal blood flow.
Q: What foods are rich in L-arginine?
A: As a naturally occurring amino acid, L-arginine can be found in a wide range of foods that are rich in high-quality protein.
Some particularly good sources of L-arginine include pork loin, turkey breast, peanuts, pumpkin seeds, many different kinds of dairy, and surprisingly, even spirulina.
A diet high in these foods can naturally increase your body’s levels of L-arginine without the need of a supplement. Powder or capsule-based L-arginine, on the other hand, is a great addition to a protein shake or a smoothie if you want to add some more L-arginine to meals that would otherwise be devoid of it.
Q: How can you increase nitric oxide without L-arginine?
A: If you want to stimulate your body to produce nitric oxide without using an L-arginine supplement, you have two good options.
The first is to take a supplement that provides other molecules used in the same chemical synthesis pathway that L-arginine uses, and rely on the L-arginine that your body gets naturally from your diet. A good example of another compound related to the same nitric oxide production pathway is citrulline.
Alternatively, you can try stimulating nitric oxide production through a different pathway entirely. The best way to do this is with beetroot juice or a beet supplement, which contains natural sources of nitrates, which also increase nitric oxide production through a completely different molecular pathway. The end result is the same, though: better blood supply thanks to vasodilation induced by nitric oxide.
Q: Can L-arginine help with erectile dysfunction (ED)?
A: L-arginine is a common ingredient in male enhancement pills and other sexual wellness supplements for men because of its ability to increase nitric oxide production. Some research has drawn a connection between low nitric oxide levels and poor erectile function.
A review article published in the journal Cardiovascular Research pointed out that both erectile dysfunction and heart disease share many of the same risk factors: obesity, smoking, and high blood pressure, to draw just a few examples (8).
All of these risk factors modulate your body’s ability to regulate blood vessels using nitric oxide, which suggests that L-arginine, which increases nitric oxide production, could assist with erectile dysfunction.
A 1999 study confirmed this hypothesis, demonstrating that men with erectile dysfunction who had low levels of nitric oxide production reported substantial improvements in sexual function after taking an L-arginine supplement (9).
However, this study did note that not all cases of erectile dysfunction can be attributed to low nitric oxide levels, so while L-arginine may certainly help, it’s not going to be the solution for everyone.
Q: How should you take L-arginine?
A: L-arginine should be taken at a fairly high dose, between three and eight grams per day depending on your body size.
It’s not clear whether you should take this dosage all at once, or spread it throughout the day—there hasn’t been enough research comparing these different dosing protocols.
If you are looking to boost your recovery after a tough workout, though, you should definitely take your L-arginine dose all at once, and combine it with one gram of carbohydrates per kilogram of body mass (or half a gram of carbs per pound of body weight, roughly).
Q: What does L-arginine do for your sexual health?
A: Since L-arginine plays an important role in the synthesis of nitric oxide, it can be a helpful supplement for men who have erectile dysfunction.
Since men’s ability to get and sustain an erection is dependent on their ability to maintain blood flow, low levels of nitric oxide have been linked to erectile dysfunction in men, and L-arginine supplementation appears to help these men.
Interestingly, some research has suggested that women may also benefit from multi-ingredient supplements designed to boost L-arginine levels, but the research on this subject is not definitive (10).
L-arginine supplements can be used by people looking to boost their athletic performance through increased muscle blood supply, and by people who are overweight, obese, or just want some help lowering their risk factors for heart disease.
By upregulating your body’s nitric oxide production, L-arginine can improve sports performance as well as decrease blood pressure.
Additionally, it may help alter your body’s carbohydrate metabolism in a favorable way, which can help athletes recover and refuel after a tough workout, and also help people who are overweight, obese, or who have metabolic syndrome.
L-arginine might be even more helpful for increasing your aerobic and anaerobic performance if it’s taken alongside with other components in your body’s nitric oxide synthesis pathway, such as citrulline.
Whether it’s beneficial to take L-arginine alongside other nitric oxide boosters like beet supplements remains an open question. Nevertheless, L-arginine is a good bet for both boosting athletic performance and reducing blood pressure.
For Alpha XR‘s #1 L-arginine recommendation, click here.