What are L-Arginine Benefits and Side Effects?

L-Arginine Benefits and Side Effects

L-arginine is most commonly known and used in the fitness industry for its ability to stimulate the release of growth hormone. Hence the reason why it is used in the body building world for enhancing stamina, strength, and performance. In this post we will discuss in more detail l-arginine benefits and side effects so you can make a more informed decision about whether this is a supplement that is right for you.

What Exactly is L-Arginine?

weight lifting

L-arginine is an amino acid used by the body in the biosynthesis of proteins, and is found naturally in dairy products, red meat, fish, poultry and eggs. It is converted in the body to nitric oxide: a chemical that opens blood vessels wider, in turn improving the flow of blood around the body.

It is a conditionally essential amino acid, meaning that it is not always essential, except maybe in times of illness and stress, such as the stress put on the body due to hard training or lifting weights. These conditions will cause catabolic stress and injury so under these circumstances the body requirements for l-arginine will be much higher.

It also has many uses other than just stimulating your growth hormone, so let’s dive right in and take a look at these.



beautiful glowing skin

One of the most powerful effects of l-arginine is its ability to boost immune function; and it may also help fight the inflammation that can cause some diseases in the first place. Out of control chronic inflammation is now thought to be the root causes of many inflammatory diseases, therefore, reducing it as much as possible can be very helpful to health.

It works like this: l-arginine’s antioxidant mechanisms help it to scavenge the free radicals that accelerate telomere aging. With the shortening of telomeres comes faster aging and increased susceptibility to age related diseases such as cancer, diabetes, Alzeimer’s, dementia, and heart disease.

Eat as many antioxidants as possible:-

The above is not a pretty list; and the very reason why it is SO important to have a regular high intake of antioxidants, be they from l-arginine, or/and from other sources such as those found in fresh fruits and vegetables. Please read this list of the highest antioxidant rich foods to find many more, and start incorporating them into your diet as much as possible.


skin aging process

Combining Supplements:-

topless man with muscles

Supplementing l-arginine with a combination of vitamin C and Omega 3 fatty acids will make for an effective all round anti aging combination. And taking l-arginine along with regular exercise (which is vital for heart health and to keep muscle mass up, especially as you age) will bring on  hormonal changes that can help build a more powerful, youthful and toned body.

The role of collagen

L-arginine can also help improve collagen synthesis in the skin. We’ve all heard of the importance of collagen in the aging process; collagen declines as we get older, giving the appearance of thinner, less plump skin (yikes), and taking supplements that help synthesise this precious collagen from the inside (such as l-arginine) is a very important part of negating this. Be mindful that most so called collagen infused face creams and beauty products are not able to cross through the skin barrier to be of any use, and are therefore often an expensive waste of money.



L-arginine improves the flow of blood, making it easier for the body to transport nutrients and oxygen to muscle and joint tissues. This will have the effect of giving you less pain if any kind both during and AFTER exercise (especially weight bearing exercise where muscles are more easily torn).

The main reason l-arginine is so commonly used in the body building and fitness industry is because of its ability to naturally increase the production of HGH (human growth hormone) and other amino acids such as l-glutamate, l Proline, and creatine.

L-arginine improves insulin sensitivity which makes its part in metabolic health important as it may help build lean muscle, fight joint inflammation and pain, repair injured tissue; and is also a great soother for the central nervous system.

How Much Do I Need To Feel the Benefits?

The most powerful muscle building effects from l-arginine come when combined with exercise, especially weight bearing, gym, circuit training, and boxing. Doses of 5-9 grams per day can increase resting growth levels by a minimum of 100%, and when exercising by up to 500%.


Male Fertility:-

single sperm

L-arginine helps blood circulation and the replication of cells, thus helping to improve sperm production and motility. Some studies show that, combined with other anti inflammatorys and antioxidants, l-arginine supplements can significantly improve up to 92% of male infertility cases.

This proves even more true for highly stressed men, as stress lowers l-arginine in the sperm production paths. Supplementation has also been proven to work more effectively when combined with l-glutamate and Yohimbine Hydrochloride.

Female Fertility:-

pregnant woman

L-arginine can also be beneficial in the treatment of female infertility, as it can actually increase the circulation to the genital tissue in both sexes.

Research suggests that l-arginine and NAC together may help to naturally balance hormones, playing a role in helping to alleviate inbalances of estrogen and PCOS.


Not only does l-arginine supplementation support cardiovascular and kidney health, but it also regulates the immune system by positively affecting immune responses and inflammation.

I found during my research, many studies to support these findings, especially when supplemented along with omega 3 fatty acids and other antioxidants, such as Vitamin E and C.


human heart valvesAs a popular supplement recommended by cardiologists, l-arginine improves heart health by lowering inflammation, boosting the health of blood vessels and the health of the whole cardiovascular system, lowering high blood pressure, and improving stamina.

And for those at high risk of heart disease, supplementation of l-arginine may act as a powerful and preventative measure against stroke and heart attack. But do be sure to use it alongside a good nutritional and exercise plan as nothing makes up for the lack of these two!


bicep curls

L-arginine is already made in adequate amounts by the body in a person who eats a healthy diet, and therefore no supplementation would be required. However, in those partaking in high amounts of physical activity and looking to cut fat and build muscle then this could be a helpful supplement in that process and may give you that extra edge you are looking for.

I must reiterate again that I can only find evidence of l-arginine’s usefulness when used either for medical reasons, OR in combination with physical exercise when the body has a higher demand for amino acids in the rebuilding torn muscle tissue. In most other cases you should simply get enough from your diet alone.


2-3 grams up to 3 times daily is the adequate amount that has been studied in trials, but always buy from reputable companies, and always read labels carefully. The last thing you want to do is load your body up with synthetic chemicals, fillers, and preservatives. And definitely do not exceed recommended doses.

I have found some good quality supplements on Amazon that have all the above requirements if you want to take a look: —>Pure Science L Arginine Capsules<—


L-arginine is safe for most people when either taken in capsules, powder, administered in a shot, or applied to the skin in appropriate doses.

In clinical settings, l-arginine has been trialed safely with only minor side effects, and has been proven to be beneficial in those who need it for medical reasons (in which case consult with your doctor first), OR for those who are doing a lot of physical activity and are looking to get into shape, cut fat, and build muscle.

Possible side effects may include:-

Bloating, diarrhea, gout, allergies, inflammation of airways, asthma may worsen, may interact with medications that lower blood pressure. Always consult with your doctor before use or if you have any of these side effects. These supplements are not intended to treat illness or disease.

I hope you have found what you are looking for in this article; if not then feel free to leave any comments or questions in the thread below and I will get back to you as soon as I can. Thanks for reading!

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Stefanie Taylor
Plant based eating is set to EXPLODE in 2019! And I myself have been living this healthful lifestyle for over 2 years and feel pretty awesome for it. So, I decided to design this website to share the experiences of my own plant based transformation with others; and to also show how I did it safely and healthily to ensure I met all my nutritional requirements.

Good nutrition has helped me through many health issues in the past. I have lived, breathed, studied, tried, and tested healthy foods and food fads for as long I can remember. but I know that plant based eating is most definitely here to stay. Additionally, I have studied Sports Nutritional Advisory, Nutritional Therapy, and Clinical Weight Loss to add to my knowledge and understanding of nutritional human needs.

This website is not intended to treat or diagnose any medical disease or illness. It's merely meant as a way of showing you how to boost your health through the eating of more nutritious plant foods, instead of junk foods.

Oh, and thanks for stopping by! Have a happy plant based life, and please feel free to drop me a line in the comments thread below any time :)

14 thoughts on “What are L-Arginine Benefits and Side Effects?”

    • That’s interesting William, I would be interested to know how you feel it is working for you and if you have any side effects? Thank you for reading.

  1. Wow this stuff is great, I just bought some of this stuff, but the dosage is on milligrams, I take 8.5 milligrams is that too much???

    • Hi Jalal ok don’t panic, usually the dosage is in grams as it is quite a bulky thing (you can even find it in powder form). In my article I speak of the dosage in grams (there are 1000 milligrams in 1 gram), so you are actually taking a minute amount so definitely not too much.

      I can only presume you have got in some kind of really condensed extracted form which could explain why it is in such tiny amounts. I would just take what it says on the label as it has obviously been worked out correctly. But in my research on L Arginine I didn’t come across it in this form. I would be very happy to look into it more if you want to send me a picture of the labeling.

  2. I actually do intermittent fasting and I really would love to have the benefits of l arginine but my coach says I should not take it before workouts. What do you recommend for people who do intermittent fasting?

    • Hi Furkan, thanks for reading. I don’t know the specific reasons why your coach has told you not to take it before your workouts as in the research I have done I have found a lot saying you should take it both before (30-60 mins)and also after. Some people have side effects of stomach ache and nausea etc so I presume if you are one of those people then you shouldn’t take it before. Anyway, maybe you could ask your coach and let me know his reasons as I would be intersted, and I want to make sure that I have all the correct information.

      As for intermittent fasting, you would have to tell me more about how often you do this and when. Obviously if you are on a fast then you wouldn’t want to put amino acids into your body (but this may depend how strict the fast is and your reasons for doing it).

      In my research on L Arginine (and I have done quite a lot) I can find no clear answer as to whether it should be taken on an empty stomach or with food, as the true data about what is best is just not available yet. There is an argument for taking it on an empty stomach so it doesn’t have to compete with other amino acids for absorption, and then there is argument saying it should be taken with food as the nutrients in the food will ENHANCE absorption.

      So, I guess you have to experiment with what works best for you, bearing in mind possible side effects.

  3. Very interesting article about L Arginine. All of the information that is needed on this subject is shown here. You had given other uses for this supplement besides body building.

    • Hi Tony, thanks for reading and yes there are many reasons to use this supplement, including medically, which is an eye opener for most people. Very interesting indeed!

  4. Very interesting and helpful. I’m interested in anything thats anti aging these days. Also keeping up with my health from the inside out. Thank you for this article.

    • Hi Toni, glad you found this interesting, a lot of people are getting into the healthy thing these days, which is great. Just keep everything natural and you won’t go far wrong.

  5. So many benefits for L-Arginine. If we eat a lot of the food high in this supplement such as eggs and fish, is that sufficient or do we need more? I guess I am curious how much I need to supplement. I eat 2 to 4 eggs a day, I know seems like a lot. Maybe I need to look up how much 1 egg provides.

    • Hi there, I don’t think you need to worry about your egg intake as they are such a great source of protein and other nutrients and they definitely have a place in a healthy diet. As for L-Arginine, I think you would only need to supplement if you had any of the risk factors or reasons to stated in the post, OR maybe if you workout a lot or are on a vegan diet maybe.

  6. Great article about L-Arginine. It is necessary for many of our health and strength of our body especially in growing kids. I really love that you have mentioned every bit of it. It doesn’t have side effects for most of the people and really great to attain a good health.

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