Does Arginine Work? It Might Not Give You a Pump, but Don’t Miss Out on its Other Benefits!

If you go to GNC and look at many of the supplements that are supposed to give you a nice big pump in the gym, you will find that many of them contain arginine, and many of them list arginine as the first ingredient. But does arginine actually cause an increase in nitric oxide and thus give your muscles the pump you are looking for? Furthermore, does arginine have any other benefits that will be useful on your quest to a lean, strong physique? The answer may surprise you!

 Does arginine make your muscles HUGE in the gym?

Putting arginine in pump-boosting pre-workout supplements was only a logical thing to do. After all, arginine is a precursor to nitric oxide, which is the main chemical responsible for the pump that you get after a set and the huge veins you see in the mirror. Contrary to what some say, recent evidence has shown that the pump you get in the gym does contribute to the hypertrophic effect of training as well as activation of muscle satellite cells – that is, in building more muscle mass after you lift [1, 2]. However, that discussion is for another article.

So, the supplement companies started putting arginine into their pre-workout supplements and saying that you would get a pump from it. All good so far. There were even some mouse studies showing that there was indeed an increase in NO (nitric oxide) from arginine. The problem with these mouse models is that they injected the arginine into the mice. I don’t know about you, but I tend to take my pre-workout supplement orally, not intravenously. It turns out that when you take arginine orally with a drink, it does not actually make it to the muscle cells to get metabolized into NO there. When we actually had decent human randomized controlled trials, arginine was shown to have no effect on blood flow, nitric oxide production, or performance [3, 4]. From Liu et. al.,

“The results of this study suggested that short-term arginine supplementation had no effect on nitric oxide production, lactate and ammonia
metabolism and performance in intermittent anaerobic exercise in well-trained male athletes.”

So then arginine is useless, right?

So then does that mean that arginine is pretty much useless for anything? I thought so for a long time after discovering that it had no effect on training or nitric oxide production. However, research on arginine was not over yet, and since the discovery that arginine was useless as a nitric oxide booster, there are some other certain properties of arginine that have me taking it virtually every single day.

Arginine has the potential to increase muscle growth over time

In one study, the test subjects took 3 g L-arginine, 2.2 g L-ornithine and a humongous 12 mg vitamin B12  twice a day for 3 weeks while the control group took a placebo. The study is confounded by the fact that they took ornithine and B12, however ornithine easily converts into arginine in the body. The subjects were powerlifters and they did a few sets each workout session. The lifters did bench press, squats and deadlifts. For each exercise they did 5-8 sets of 1-3 reps at 90 – 120% 1 rep maximum [5]. The researchers found that the concentration of growth hormone rose more after the workout in the group that took the supplements:

(image from

That’s a nice benefit, I guess. However, contrary to popular belief, increases in growth hormone are not well corrolated with muscle gain. A growth in muscle tissue is controlled on a more local level, and IGF-1, which is made from growth hormone but has different functions, has more to do with it. Luckily, the scientists saw IGF-1 increase as well:

(image from

One thing to keep in mind, though, is that the researchers did not measure the actual growth in muscle tissue over the three weeks, and hormonal elevations like GH and IGF-1 are not so great at predicting muscle growth over a long time. Still, the results of the study are very positive.


Don’t worry, it gets better…

Arginine decreases fat mass, improves insulin sensitivity, improves endothelial function, and flips genes that make fat get stored in your muscle rather than fat cells!

Here is where things really get interesting. In type 2 diabetics, arginine was shown to improve insulin sensitivity, endothelial function, oxidative stress, adipokine release, as well as decrease fat mass [ 6]! The main advantage to this study was that the supplemented subjects as well as the control group were placed on an exercise program and had to undereat. Arginine had an additive effect on all of the above parameters on top of the diet and exercise! According to the authors,

“In conclusion, a relatively short period of changes in lifestyle can improve glucose and insulin levels and endothelial function. Interestingly, L-arginine therapy seems to further improve several metabolic features characteristic of the metabolic syndrome, such as fasting and postprandial glycemic excursions, hyperinsulinemia, hypertension, visceral obesity, endothelial dysfunction, and unbalance in adipokine release.”

So, arginine makes exercise and diet even healthier as well as decreases visceral fat more than diet and exercise alone. Visceral fat is the fat inside you near your organs (as opposed to the saggy type of fat under the skin – subcutaneous fat) and is the most harmful fat from a longevity standpoint.

There have been other studies showing increases fat loss and/or decreased fat gain from taking arginine every day. Monti et. al., added 6.6g of arginine into biscuits and having their participants eat them every day and showed that “circulating glucose, proinsulin/insulin ratio and fat mass were decreased compared with the placebo biscuit recipient group.”[7] The arginine group lost 2 kg of pure fat while the placebo group only lost around 0.7 kg of fat in 2 weeks!

If that isn’t enough for you yet, how about the fact that arginine has been shown to flip the expression of certain genes with the net effect of having excess energy shuttled away from your fat cells and toward your muscle cells [8]! To date, this is one of the only common supplements known to have this effect. Most supplements that increase insulin sensitivity, for example, increase insulin sensitivity everywhere, not specifically in the muscle. According to the authors of this study,

“Dietary Arg supplementation increased mRNA levels for fatty acid synthase in muscle, while decreasing those for lipoprotein lipase, glucose transporter-4, and acetyl-coenzyme A carboxylase-? in adipose tissue. Additionally, mRNA levels for hormone sensitive lipase were higher in adipose tissue of Arg-supplemented pigs compared with control pigs. These results indicate that Arg differentially regulates expression of fat-metabolic genes in skeletal muscle and white adipose tissue, therefore favoring lipogenesis [fat storage] in muscle but lipolysis [fat release] in adipose tissue. Our novel findings provide a biochemical basis for explaining the beneficial effect of Arg in improving the metabolic profile in mammals (including obese humans).”

Now that is something!

Other possible mechanisms of action?

Adel Musso from Suppversity has suggested the following possible mechanisms of action for how arginine could promote fat loss and body recompositioning:

“Stimulation of [lipolysis] (release fat from adipose tissue); activation of genes that are responsible for the oxidation of fatty acids; interaction with PGC-1 alpha and triggers mitochondrial biogenesis and the“browning” of fat; regulation of adipocyte-muscle crosstalk resulting in an energy repartitioning effect away from the adipose and towards the muscle tissue; activation of the AMPK pathway, resulting in improvements in both lipid and glucose metabolism.”

Now, there have not been many long term studies investigating whether a diet that is already very high in protein (and thus, high(er) in arginine) would still show a benefit of supplementing with arginine on its own. Considering that a high quality protein, such as Whey, will only have about 0.5g of arginine for about 25g of protein, I would venture to guess that you would still see benefits with a high protein diet. Just know that this is not confirmed at the moment.

How to use arginine

It is important that you use arginine at the right time. There is little research showing that arginine has any benefit pre-workout, so there is really no need to take it before the gym. What really matters is taking it with your carbs. Arginine will make the pancreas secrete insulin, so if you do not have carbs after your arginine (or with your arginine), then you blood sugar can possibly drop, which can make you feel hungry. Not good if you are trying to lose weight. On the other hand, having an appropriate insulin spike with a carb meal is actually a very beneficial thing. A characteristic of diabetes is an absence of the initial spike in insulin following a carb-rich meal.

Thus, taking about 3-4g of arginine with your meals that are highest in carbs is going to give you the most benefit. The research currently supports 9-10 g of supplemental arginine per day for body recomposition results. For me personally, this means I take all of my arginine during my post-workout meals.

The most practical, cheapest, and sane way of doing this is to buy a back of bulk arginine from amazon or another bulk supplier and in the morning or whenever, create a drink that has 10g of arginine in it. I mix it with crystal light for taste and lemon juice to counter arginine’s awful taste (you’ll want the lemon juice, trust me). Then just drink a third of that drink 15 minutes before (or during if you don’t have time) your 3 biggest carb meals. Don’t go for pills – super expensive in comparison and you’ll be popping a ton of pills.

Now remember, it has been shown that arginine amplifies the effects of diet and training! So you still can’t sit on your butt all day long, eat, and think arginine will fix it all. It won’t. But if you are busting your butt in the gym and have your diet in order, arginine might just give you the extra help you need!


If you would like to see the sources referenced in this article in an easy-to-read, interactive format, click here.

If you would like to get the best price on a pure L-Arginine supplement, try Powder City; it is my favorite bulk supplier for supplements. To save 10% off your order and make it even cheaper, use the following link and the coupon code it gives you:
(I buy most of my bulk supplements from Powder City because of the price and purity. I would never recommend a brand I did not use myself or didn’t believe in.)


Have any questions not covered in this article? Don’t be shy to comment below!



1. “Involvement of Nitric Oxide Synthase in Skeletal Muscle Adaptation to Chronic Overload.” Journal of Applied Physiology. N.p., n.d. Web. 01 Oct. 2014.

2. Anderson, J. E. “A Role for Nitric Oxide in Muscle Repair: Nitric Oxide-mediated Activation of Muscle Satellite Cells.” Molecular Biology of the Cell 11.5 (2000): 1859-874. Web.

3. Fahs, Christopher A., Kevin S. Heffernan, and Bo Fernhall. “Hemodynamic and Vascular Response to Resistance Exercise with L-Arginine.”Medicine & Science in Sports & Exercise 41.4 (2009): 773-79. Web.

4. Liu, Tsung-Han, Ching-Lin Wu, Chi-Wei Chiang, Yu-Wei Lo, Hung-Fu Tseng, and Chen-Kang Chang. “No Effect of Short-term Arginine Supplementation on Nitric Oxide Production, Metabolism and Performance in Intermittent Exercise in Athletes.” The Journal of Nutritional Biochemistry 20.6 (2009): 462-68. Web.

5. Zajac, Adam, Stanis?aw Poprz?cki, Aleksandra ?ebrowska, Ma?gorzata Chalimoniuk, and Jozef Langfort. “Arginine and Ornithine Supplementation Increases Growth Hormone and Insulin-Like Growth Factor-1 Serum Levels After Heavy-Resistance Exercise in Strength-Trained Athletes.” Journal of Strength and Conditioning Research 24.4 (2010): 1082-090. Web.

6. Lucotti, P., E. Setola, L. D. Monti, E. Galluccio, S. Costa, E. P. Sandoli, I. Fermo, G. Rabaiotti, R. Gatti, and P. Piatti. “Beneficial Effects of a Long-term Oral L-arginine Treatment Added to a Hypocaloric Diet and Exercise Training Program in Obese, Insulin-resistant Type 2 Diabetic Patients.”AJP: Endocrinology and Metabolism 291.5 (2006): E906-912. Web.

7. Monti LD, Casiraghi MC, Setola E, Galluccio E, Pagani MA, Quaglia L, Bosi E, Piatti P. l-Arginine enriched biscuits improve endothelial function and glucose metabolism: A pilot study in healthy subjects and a cross-over study in subjects with impaired glucose tolerance and metabolic syndrome. Metabolism. 2013; 62:255–26.

8. Tan, Bie, Yulong Yin, Zhiqiang Liu, Wenjie Tang, Haijun Xu, Xiangfeng Kong, Xinguo Li, Kang Yao, Wanting Gu, Stephen B. Smith, and Guoyao Wu. “Dietary L-arginine Supplementation Differentially Regulates Expression of Lipid-metabolic Genes in Porcine Adipose Tissue and Skeletal Muscle.” The Journal of Nutritional Biochemistry 22.5 (2011): 441-45. Web.