When to take L-Arginine | PlanYourVitamins.com

What is L-arginine good for?

Short answer: L-arginine has potential benefits for cardiovascular health, blood pressure, athletic performance, diabetes and nitric oxide production.

L-arginine is an amino acid required for creating proteins, and is also involved in promoting blood circulation.

L-arginine for blood circulation

Specifically, L-arginine is converted into a chemical called nitric oxide by your body, and this chemical causes the blood vessels to expand, resulting in an improved blood flow.

This has also been shown to directly benefit people who suffer from conditions such as peripheral artery disease by improving the function of blood vessels that have been narrowed due to atherosclerosis. For this reason, L-arginine, together with L-citrulline, are the two most common ingredients to be found in nitric oxide boosting supplements.

A 2021 meta-analysis found that L-arginine supplementation could help to reduce high blood pressure through the same mechanism, although interestingly this was observed to work more effectively in women than in men. It has also been observed that L-arginine supplementation can have a positive effect on overall aerobic and anaerobic performance.

L-arginine for diabetes

Furthermore, a 2017 study revealed that L-arginine supplementation in middle aged adults who suffered from metabolic syndrome and impaired glucose tolerance resulted in an improvement for both issues, and it was concluded that this could help to significantly delay the onset of diabetes.

When should I take L-arginine?

Short answer: L-arginine is best taken on an empty stomach, at least 2 hours since the last meal and at least 30 minutes before the next meal. For workouts, it can be included in your pre-workout routine.

L-arginine is a popular supplement in the world of exercise, and a 2020 meta-analysis was performed to determine the best time for taking L-arginine in order to take advantage of its benefits for athletic performance. It was found that taking L-arginine between 60 to 90 minutes before exercise yielded the most effective results, so you may want to incorporate it into your pre-workout routine, depending on the timing.

Otherwise, being a single amino acid, it is recommended to take L-arginine between meals, on an empty stomach, in order to maximize absorption.

What does L-arginine combine well with?

Short answer: L-Arginine has been shown to work well together with B-complex, garlic extract, L-citrulline, L-lysine, pine bark extract, vitamin B6, vitamin B9, vitamin B12 and vitamin C.

With vitamin C, for antioxidant effects

L-arginine's benefits to cardiovascular health seem to be amplified when combined with vitamin C, in particular due to the way in which L-arginine improves endothelial function, that is, the function of the inner lining of the blood vessels, together with vitamin C's antioxidant properties.

Research showed that after one month of supplementing vitamin C and L-arginine, a significant improvement was observed in people suffering from the cardiovascular side-effects of COVID-19 infection.

With L-lysine, for stress & anxiety

L-arginine also seems to pair well with another amino acid, L-lysine, by promoting the production of collagen and enhancing bone formation, as well as normalizing hormonal stress response in humans that suffer from high trait anxiety. L-arginine and L-lysine are thought to have a synergistic effect when combined due to the way in which they share the same pathways in the body.

That said, high levels of L-arginine could result in lower levels of L-lysine, as they compete for absorption, so it is advised to combine them in moderation.

With B vitamins and garlic extract, for cardiovascular health

Another study looked at the potential for combining L-arginine with aged garlic extract and vitamins B6, B9 and B12 to help treat atherosclerosis, the hardening and narrowing of the arteries due to plaque buildup. The study found that this combination was particularly effective at reducing the progression of the disease, in addition to improving several other aspects of cardiovascular health.

With pine bark extract, for erectile dysfunction

L-arginine has also been studied in combination with Pycnogenol, which is a particular formulation of pine bark extract, for its potential as a treatment for erectile dysfunction. Studies found that the combination was particularly effective in helping men aged between 25 to 45 to achieve normal erections.

With L-citrulline, for nitric oxide production

L-arginine and L-citrulline are two compounds which are known to promote the production of nitric oxide, a chemical that serves to relax and dilate our blood vessels, reducing blood pressure, improving blood flow, and enhancing overall cardiovascular health. The two can frequently be found combined in supplements marketed as "nitric oxide boosters".

What are natural sources of L-arginine?

If you are interested in achieving your daily L-arginine intake through your diet, rich sources of L-arginine include:

Turkey
Pork
Chicken
Pumpkin seeds
Milk
Cheese
Yoghurt
Lentils
Chickpeas

One more thing regarding L-arginine

Our body's ability to process L-arginine supplements declines as we get older, so it is advisable to seek advice from your trusted doctor before taking any supplements containing L-arginine in order to ensure that they are suitable for you.

L-Arginine data sources & further reading

Last updated by Asklepios on 30th January, 2025