The Fast Facts
- L-arginine, which is the supplement form of arginine, supports key functions like immune health and helps your cells work together.
- Most people get enough arginine from their diet, but you may benefit from L-arginine supplements if you have high blood pressure, erectile dysfunction (ED), or are an athlete.
- Our dietitian recommends trusted brands like Nutricost and Thorne as the best L-arginine supplements on the market.
Your body needs arginine, more commonly known as L-arginine in supplement form, to carry out several important functions.
It’s an amino acid that helps build proteins. It’s especially important for producing nitric oxide, which widens blood vessels to support blood flow, promoting immune function and aiding cellular communication.
While most people get enough through diet, supplements may be helpful to boost athletic performance or during certain life stages or for specific health conditions, such as pregnancy, critical illness, high blood pressure, or erectile dysfunction.
Read on for our dietitian’s top picks for the best L-arginine supplements available.
A note on price
General price ranges with dollar signs ($ to $$$) are indicated below. One dollar sign means the product is rather affordable, whereas three dollar signs indicate a higher price.
Generally, prices range from $0.15–$2.00 per serving, or $14.97–$42.00 per container, though this may depend on where you shop.
Formulations for athletes tend to be more expensive.
Note that serving sizes vary by product but are generally 1–4 capsules.
Pricing guide
- $ = under $0.25 per serving
- $$ = $0.25–$1 per serving
- $$$ = over $1 per serving
• trusted by healthcare professionals
• dairy, soy, and gluten-free
• affordable
• third-party tested
• non-GMO, gluten-free, and vegetarian
• affordable
• high dose might not be suitable for some
• contains other ingredients that may benefit athletes
• made without caffeine, gluten, or soy
• only contains 20 servings per container
• only contains one ingredient
• third-party tested
• affordable
• no flavored varieties
• vegan-friendly
• made in GMP-compliant facility
• easy to swallow
All products included in this list have undergone Healthline’s extensive vetting process. We also evaluated the top L-arginine supplements based on these criteria:
- Third-party testing: We prioritized supplements that are tested by an independent lab to ensure quality, safety, and purity.
- Transparency: We looked for brands that clearly state the exact amount of L-arginine in each serving and are open about how ingredients are sourced.
- Ingredient quality: We chose supplements that contain high quality ingredients, without unnecessary fillers and additives.
- Customer reviews: We checked online reviews to evaluate how users rate the effectiveness, taste, and overall experience of each supplement.
- Price: We included products available at a variety of price points, without compromising on quality.
- Dosage: We selected supplements that provide L-arginine in clinically studied doses.
When shopping for L-arginine supplements, seek out products that have been third-party tested to ensure quality. Although the FDA regulates dietary supplements, this is 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’s a gluten-free, allergen-free, organic, or GMO-free product.
Because L-arginine is primarily found in animal foods, some L-arginine supplements are not vegetarian. If you’re vegan or vegetarian, look for supplements specifically labeled as suitable for these diets.
If ED is your primary concern, you should consult a healthcare professional for more treatment options.
Dosage
Keep in mind that L-arginine isn’t an essential nutrient, so no set dosage guidelines exist. Your healthcare professional may give you dosage guidance if you need it.
Dosing depends on what you’re intending to treat. For example, higher doses of L-arginine may be helpful for improving ED symptoms and athletic performance, while lower doses may be appropriate for treating other symptoms or medical conditions.
It’s important to understand that, because L-arginine is conditionally essential and supplementation has been shown to benefit only certain populations, most people do not need to supplement with L-arginine.
If you’re interested in taking a supplement containing L-arginine to treat a specific medical condition like ED or to improve athletic performance, discuss dosing with your healthcare professional.
Even though L-arginine supplements are generally safe to take, they’re not appropriate for everyone and may interact with commonly prescribed medications.
It’s also
Most people do not need to supplement with L-arginine. This is because the body can meet L-arginine demands through dietary consumption of protein sources like fish and nuts, body protein breakdown, and endogenous L-arginine production by the kidneys.
Research suggests that L-arginine supplements are generally safe for most people, even when taken in high doses for long periods. However, some people may experience side effects like stomach pain and diarrhea when taking
L-arginine supplements aren’t safe for everyone. If you have any underlying health conditions or are taking medications, check with a doctor before starting supplementation.
L-arginine supplements are generally not recommended for people who have:
- kidney disease
- low blood pressure (hypotension)
- guanidinoacetate methyltransferase deficiency, an inherited condition that impacts arginine metabolism
L-arginine may also interact with medications like those used to treat high blood pressure.
Check with a healthcare professional if you have questions about taking L-arginine supplements. They can help you determine whether L-arginine supplements are safe and appropriate for your needs.
Useful supplement shopping guides
Check out these two articles to help make supplement shopping a breeze:
Research suggests that L-arginine supplements are generally safe for most people, even when taken in high doses of up to 30 g per day for long periods of time. Most supplements contain only around 1-5 g of L-arginine, so it would be difficult to take too much.
Some people may experience side effects like stomach pain and diarrhea when taking more than 9 g per day.
Also, do not give your child L-arginine unless it’s medically necessary and was suggested by a healthcare professional. Giving a child too much L-arginine is extremely dangerous and can be fatal.
There are several different forms of L-arginine supplements. Talk with a trusted healthcare professional like a physician or registered dietitian to see which one is right for you.
Some research suggests that L-arginine may help improve symptoms of ED when taken in specific doses. For example, a 2022 study in 98 people found that a daily dose of 6 g of L-arginine for 3 months significantly improved erectile function in people with mild-moderate ED.
Do not take L-arginine supplements for ED without discussing it with a doctor first. L-arginine has the potential to interact with medications, including those used to treat ED, like Viagra.
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, people who are pregnant, infants, and those who are critically injured or ill may need more arginine than they can produce on their own.
Be sure to talk with a healthcare professional before adding supplements to your routine.