Last updated: November, 2023
Recently, L-arginine has gained popularity well outside the gym because of its many proven benefits. If you are looking for the best L-arginine supplement, here is what you need to know to get the best results and choose the right product.
- What Is L-Arginine?
- Types of L-Arginine Supplements (Pure, HCL, and AAKG)
- 2021’s Reviews of the Best L-Arginine Supplements
- Benefits of L-Arginine
- Who Should Take L-Arginine?
- FAQs about L-Arginine
What Is L-Arginine?
Arginine is one of the 21 amino acids your body needs for tasks like protein synthesis and enzyme reactions. Arginine is not considered essential because your body can make it out of other amino acids. However, it is considered to be a conditional amino acid.
Conditional amino acids are ones that your body can make it from other amino acids but don’t necessarily make enough of.
There are many roles of arginine in the body, such as healing wounds and building muscles. The big benefit of arginine though is that it is used as a precursor to nitric oxide (NO).
Why Nitric Oxide Matters
Like with most molecules found in the body, there are many roles of nitric oxide. It:
- Dilates blood vessels and arteries
- Acts as a neurotransmitter
- Improves blood flow
- Relaxes smooth muscle tissue
- Controls GI tract contractions
- Regulates immune response
For athletes, the most important role of nitric oxide is its ability to relax arteries. When the arteries are relaxed, more blood is able to get through – which in turn means more blood can get to muscles. The idea is that taking L-arginine supplements to increase NO will allow more blood (and nutrients) to get to muscles. (1,2)
Difference between Arginine and L-Arginine
Arginine is the name of the amino acid our bodies use. When referring to the synthetic or supplemental form of arginine, it is called L-arginine.
When it comes to benefits and results, there is no real difference between Arginine and L-arginine. (3)
Types of L-Arginine Supplements (Pure, HCL, and AAKG)
When looking for the best L-arginine supplements, you will notice that there are three different types which may be listed on the label. These all essentially do the same thing, but there are some subtle differences to note.
- Pure L-Arginine: When the ingredients list just L-arginine, it is the pure form. The important thing to know is that it tastes REALLY bad and has a texture like salt.
- L-Arginine HCL: This is L-arginine which has been bonded with hydrochloride. The reason for the HCL is to get rid of the bad taste. Since it is bonded and not pure, the supplement will actually only contain about 70 to 83 percent arginine. So, a 1000mg dosage of L-arginine HCL will only really give you upwards of 830mg of L-arginine!
- AAKG: This stands for arginine alpha-ketoglutarate. It is a synthetic type of L-arginine. It is better absorbed, more effective and provides better pumps. However, because it is synthetic, there is a risk that there might be harmful additives or byproducts. So, when using AAKG, it is particularly important that you choose a reputable company.
In Order of Effectiveness:
- Pure L-arginine
- L-arginine HCL
2021’s Reviews of the Best L-Arginine Supplements
1. Havasu Extra Strength L-Arginine
This is one of the most popular brands of L-arginine supplements. The supplement is made in the USA and has high quality standards.
Unlike the other L-arginine supplements listed here, it contains various ingredients formulated to optimize blood flow. The ingredients are 400mg of pure L-arginine, 400mg of AAKG, 400mg of L-citrulline (which is a very potent NO booster), and cayenne pepper (which is a thermogenic).
The only downside to this supplement is that it is very expensive. The entire bottle contains just 35 grams of active ingredients. If you are taking a high dosage of L-arginine daily, you’ll go through a bottle quickly.
2. NOW Double Strength L-Arginine
NOW is a really popular brand of supplements because they combine quality with affordability. One tablet contains 1 gram of L-arginine HCL. Remember that the HCL form of L-arginine is not pure, so you may only be getting 0.7grams of actual L-arginine per pill.
Even when you take this into consideration, you are still getting a really good deal. There are 120 tablets per bottle, and the bottles are cheap (especially if you buy more than one bottle at a time). It is also easy to modify your dosage by taking more/less pills.
3. Bulk Supplements Pure L-Arginine Powder
If you are looking for a very cheap L-arginine supplement, this is the one to go with. It is made out of pure L-arginine and contains no fillers or additives.
A package of the supplement contains a total of 100 grams of L-arginine. If you take 6 grams of L-arginine per day (3grams x 2 dosages), it will last you 16 days. You can save money by buying the supplement in large bulk containers.
Just note that this is a powdered L-arginine supplement. L-arginine is disgusting tasting! So, be prepared to chug it down quickly or buy some empty capsules to cap it yourself.
4. L-Arginine by Pure Label Nutrition
Take a look at the ingredients label of this supplement and you’ll see it is mostly AAKG but also contains small amounts of pure L-arginine and L-arginine HCL. It also contains 20mg of L-arginine/L-pyroglutamate.
Though it isn’t very well studied, pyroglutamate has been shown to improve neurological health. When combined with L-arginine, it is effective in treating erectile dysfunction. (32)
This formula is likely to be very beneficial for people taking L-arginine to combat the disease as well as boost training results. Yes, it is quite pricy (a single bottle contains only about 63 grams of L-arginine total). However, it is a quality product.
5. L-Arginine Fuel
I’m not actually a big fan of this product. It contains 1.5 grams per serving, which means you are getting 45 grams of L-arginine per bottle. If you go with the recommended dosage of around 6 grams per day, you’ll go through a bottle pretty quickly. To make matters worse, it is the HCL form of the supplement, so the actual L-arginine you get is less than 1.5 grams per dose.
However, I still include this as one of the best L-arginine supplements because it is cheap. As a capsule, you are also spared from the disgusting taste of L-arginine powders. If you just want to try L-arginine to see how it makes you feel, this is worth considering before you commit to a higher-quality product or bulk supplement.
For the best quality and results, go with Havasu Extra Strength L-Arginine . However, if you don’t want to spend a fortune, then you are better off with the NOW L-arginine capsules or Pure L-Arginine Bulk Powder.
Whichever L-arginine supplement you choose, remember that you’ve actually got to work out to experience benefits. So hit the gym hard to get that pump!
Benefits of L-Arginine
As Science Direct wrote, “L-arginine is one of the most metabolically versatile amino acids.” Because of its importance, there are many benefits of taking L-arginine supplements.
While the key benefits all have to do with L-arginine’s ability to increase nitric oxide (and thus increase blood flow), the benefits extend well beyond this. Taking L-arginine can improve energy levels, help glucose uptake, and reduce plasma lactate, amongst many other benefits. Here are just some of the key ones. (6)
Pre Workout Benefits of L-Arginine
L-arginine is often included in the best pre workout supplements. Once taken, the L-arginine is quickly converted into nitric oxide. Blood vessels are widened so more nutrients can get to your muscles during exercise.
The increase in NO from L-arginine supplements results in:
- More energy during workout
- Increased strength
- Better recovery
- Lean muscle gains
- Ability to work out longer without fatigue (7)
Numerous studies back up these pre-workout benefits of L-arginine. In this study, for example, the researchers concluded that taking L-arginine enhances aerobic exercise capacity.
Post Workout Benefits of L-Arginine
Trainers often recommend taking L-arginine after your workout as well. By improving blood flow, the supplement helps your body eliminate waste like lactate and ammonia which cause muscle fatigue. It also helps distribute growth hormone and improves creatine production.
As a result, L-arginine has these post-workout benefits:
- Minimizes fatigue after working out
- Reduces recovery period between workouts
- Improves recuperation
- Replenishes glycogen stores faster (when combined with a carbohydrate)
- Increases gains by aiding in protein synthesis and tissue repair
- Prevents muscle breakdown by counteracting catabolic effects of intense workouts (8, 9, 10)
L-Arginine for Erectile dysfunction
The supplement L-arginine has been highly studied as a treatment for erectile dysfunction. (11) It is important to realize that most cases of erectile dysfunction (at least ones which aren’t psychological) are caused because the body isn’t able to dilate blood vessels and get adequate blood to the penis.
All of the main erectile dysfunction medications (Viagra, Cialis, Levitra) work by increasing nitric oxide.
L-arginine supplements can be viewed as an alternative to ED medicines because they boost nitric oxide naturally.
Numerous studies show that taking L-arginine can treat erectile dysfunction. Many urologists recommend L-arginine instead of Viagra for mild and medium cases of ED. Note that L-arginine for ED is particularly effective when combined with yohimbine hydrochloride or pycnogenol. (13, 14)
Metabolism Benefits of L-Arginine
There is still a lot of research to be done on this topic. However, preliminary studies show that taking L-arginine can increase metabolism.
The metabolic benefits are likely related to how L-arginine regulates hormones, glucagon, growth hormone, and insulin sensitivity. This is very good news for people who are looking to lose weight. (15)
L-Arginine and Creatine Synthesis
One of the most popular exercise supplements, creatine is molecule similar to protein which is important for energy production.
Some of the benefits of creatine include:
- Improved performance, particularly during high-intensity activities
- Power gains
- Faster workout recovery
- Regulating neurological health
Arginine and creatine are related to each other in the body. Studies have found that supplementing with L-arginine can increase muscle creatine by 1-2%. There is still a lot of research to be done, but taking L-arginine supplements could help you get the benefits of creatine naturally. (16)
L-Arginine and Growth Hormone Release
One of the most talked-about benefits of L-arginine is that it can increase growth hormone – the hormone which is touted for improving muscle growth, fighting signs of aging, burning fat, and much more.
At dosages of 5 to 9 grams of L-arginine, studies found that growth hormone increased. The increase in growth hormone was greatest when L-arginine was combined with exercise.
Note however that it takes these large dosages of arginine to increase growth hormone amounts. At this high of a dose, L-arginine can cause side effects like diarrhea. The best way to increase growth hormone is still to exercise. So, don’t take L-arginine just for its growth hormone benefits. (17, 18, 19)
Fertility Benefits of L-Arginine
Taking L-arginine supplements has been shown to improve fertility in both men and women. In men, L-arginine can increase sperm count, quality, and fertility. In women, studies show that L-arginine improves implantation. (20)
Heart Benefits of L-Arginine
Because L-arginine relaxes blood vessels and arteries, it is often recommended for people with cardiovascular conditions. Studies show that L-arginine can benefit people with disorders like angina and congested heart failure. (21)
Who Should Take L-Arginine?
Most people are able to get enough L-arginine without having to supplement with it. However, there are some cases where the amino acid is lacking. Even when it is not lacking, certain people can benefit from L-arginine supplements more than others. These include:
- Aging People: The body’s ability to produce nitric oxide decreases with age
- Vegetarians and vegans: These people might not be getting enough arginine, especially if they don’t eat lots of nuts and seeds
- People with Digestive Problems: These may not be able to metabolize proteins well
- Smokers: Damage from free radicals can reduce levels of arginine
- Type 2 Diabetics: They have increased levels of an enzyme that degrades arginine
- Out of Shape People: Studies generally show that people who are out of shape have better results from L-arginine supplements than highly-trained athletes. (22, 23)
FAQs about L-Arginine
How to Take L-Arginine
Take L-arginine approximately 30-45 minutes before working out and again after you finish your workout. Some people also take an additional dosage of L-arginine before going to bed (1 hour after eating your last meal of the day).
L-Arginine Dosage for Working Out
Most of the info about L-arginine dosage you will find is for treating heart disease or erectile dysfunction. If this is the reason you want to take L-arginine, please consult your doctor!
As for L-arginine dosage for working out, there are a lot of varying recommendations. Here are some general guidelines:
- 3-5 grams before working out
- 3 grams after working out
- Optional additional 1-3 grams before going to bed (24, 25, 26)
Note that some people take much larger dosages of L-arginine (such as up to 10 grams before working out). These high dosages are required if you want to boost human growth hormone. However, they can also cause side effects.
Side Effects of L-Arginine
Large dosages of L-arginine can cause:
To prevent side effects, start slowly! Start by taking a small dosage (such as just 1gram) and working your way up to a higher dosage.
Note that people with herpes might experience outbreaks after taking L-arginine. People with certain disorders may experience problems like changes to their blood sugar levels, decreased blood pressure, and increased risk of bleeding. Always check with your healthcare provider before taking a new supplement! (27)
Taking L-Arginine and ED Medications
Erectile dysfunction medications work by increasing levels of nitric oxide. L-arginine also increases nitric oxide levels. The combination of the two could result in your blood vessels becomes overly dilated.
The result? Your blood pressure could severely drop. Don’t combine these products without first consulting your doctor! (28)
Natural Sources of Arginine
You don’t necessarily have to take a supplement to get arginine. There are many natural sources of arginine that can be found in food. These include:
- Grass-fed beef
- Pasture-raised poultry
- Egg whites
- Livers and organ meats
- Wild salmon
- Seeds such as sesame, sunflower and pumpkin seeds
- Kefir, yogurt, and raw cheese
- Spirulina (often found in green supplements)
- Gelatin powder
- Soy protein isolate (4, 5)
Last update on 2023-11-27 UTC -5 / Affiliate links / Images from Amazon Product Advertising API - Details