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Arginine, which is more commonly called L-arginine when in supplement form, may improve circulation as a precursor to nitric oxide (NO) — a vasodilator that widens your blood vessels, allowing for increased blood flow (
For this reason, many athletes use L-arginine for pre-workout energy. It’s also an ingredient in many male enhancement and erectile dysfunction supplements.
Arginine is an amino acid, or building block of protein, that’s found in animal products like meat, fish, and eggs. It’s considered conditionally essential, meaning that most healthy people can synthesize enough of it to meet their needs without supplementing (
However, pregnant women, infants, and people with critical illnesses or injuries may require more arginine than they can create on their own (
Healthline evaluated the top L-arginine supplements based on these criteria:
- Third-party testing. A third-party testing facility can ensure the quality and purity of the product.
- Transparency. The packaging discloses the amount of L-arginine the product supplies.
- Ingredient quality. The supplement contains high quality ingredients and avoids unnecessary fillers and additives.
Here are the 10 best L-arginine supplements for 2021.
These supplements contain only L-arginine and are best for people who may need to supplement in instances of pregnancy, injury, or illness.
This high dose, vegetarian, and gluten-free L-arginine supplement provides 1,000 mg of L-arginine per capsule. The recommended serving size is 4 capsules, which would provide a whopping 4,000 mg if you take the full amount.
You may want to consult your healthcare provider before taking such a high dose.
This Horbaach product contains a few additives, such as silica and dicalcium phosphate, but the supplement is made in a cGMP facility that meets FDA standards.
The following products have a few extra ingredients that may make them more suitable for athletes.
This supplement is designed to be taken as a pre-workout nitric oxide booster.
It contains 1,650 mg of L-arginine — some in the form of L-arginine-alpha-ketoglutarate. It also provides citrulline.
Dr. Emil’s products are third-party tested and manufactured in a cGMP lab.
In combination with other herbal supplements, nutrients, and amino acids, L-arginine is said to naturally boost male enhancement and treat erectile dysfunction (ED).
This male enhancement supplement contains a similar set of ingredients as the two previous ones on this list, including 250 mg of L-arginine, along with zinc, maca root, and Panax ginseng.
The product is third-party tested and produced in an FDA-approved, cGMP facility. In addition to the active ingredients, it contains the lubricants stearic acid and magnesium stearate, plus the anti-caking agent silicon dioxide.
When shopping for L-arginine supplements, seek out products that have been third-party tested to ensure quality. Although the FDA regulates dietary supplements, it’s minimal compared with the agency’s oversight of prescription medications.
Bear in mind that the rigor of third-party testing varies. The best way to ensure appropriate testing is to look for a label from a certification program like USP, Informed Choice, ConsumerLab, or NSF International.
If a company’s sole assertion of third-party testing is a claim on its website that doesn’t link to a specific certification program, you may want to choose another product.
If you can’t find a product tested by a third party, look for one manufactured at a cGMP facility to ensure that it meets FDA quality standards.
Next, you should choose a product that most closely aligns with your dietary needs, whether that’d be a gluten-free, allergen-free, organic, or GMO-free product.
Because L-arginine is primarily found in animal foods, many L-arginine supplements are not vegetarian. If you’re vegan or vegetarian, look for supplements that are specifically labeled as suitable for these diets.
If ED is your primary concern, you should consult a healthcare provider for more treatment options.
Keep in mind that L-arginine isn’t an essential nutrient, so no set dosage guidelines exist. Your healthcare provider may give you dosage guidance if you need it.
Still, a standard supplemental dose of this amino acid is 3–6 grams.
For reference, the average daily arginine intake from food is 4.2 grams for adults. As such, some of the supplements in this list may not boost your current intake by all that much (7).
If you plan to buy a pre-workout or male enhancement supplement, choose one that states how much L-arginine it contains. Avoid those that contain proprietary blends, as this means that the specific amounts of ingredients aren’t disclosed.
L-arginine is an amino acid precursor to nitric oxide, which helps boost circulation and blood flow. As such, it’s commonly used in pre-workout and male enhancement supplements.
Furthermore, pregnant women, infants, and critically injured or ill people may need more arginine than they can produce on their own.
Be sure to talk to your healthcare provider before adding supplements to your routine.