Getting more out of your workouts: The Leucine – OptiMSM Connection

Protein in foods we eat is typically comprised of up to 20 different amino acids. Amino acids are the backbone of the protein we eat or drink. Though known mostly for the role in building and maintaining muscle, the amino acids are used in the body for normal cellular function, to support the immune system, and much more. Of the 20 amino acids that comprise protein, some are essential in that we must get them from the diet, and some are non-essential, meaning that the body can make them from other amino acids. When you are eating and ingesting enough high-quality protein, it is easier for the body to recover from athletic events and strenuous activity. In addition, we know that when you lift weights or participate in other resistance training, over time, the body responds by increasing muscle strength, muscle size, or both. A big part of what allows the body to react this way requires protein. So, if you want to get stronger and or bigger, you are going to have to eat plenty of calories from protein-rich foods, and you are going to have to work out. Beyond those basics, there a few other things you can do to optimize your body’s response to your workouts. New research demonstrates that you can enhance the muscle’s response to exercise training beyond just eating and training.

Research has shown that higher dietary protein intakes, along with resistance training,can help increase muscle size more so than when the same resistance training is performed with lower protein intakes.1 While all of the amino acids are needed for muscle growth to occur, the essential amino acid leucine is of utmost importance due to its specific role in stimulating the growth of new muscle proteins, a process called muscle protein synthesis. In addition, having enough leucine in the diet has also been shown to minimize muscle damage and protein breakdown in response to aging, extended periods of undereating, and intense exercise.2

Another way in which leucine can impact muscle protein synthesis is through the release of the hormone, insulin. Insulin is considered more than just a hormone that helps regulate blood sugar. It is also known as an “anabolic hormone” because it has a unique effect to aid muscles in taking up amino acids, such as leucine, to trigger muscle building processes. Once leucine enters the blood, much like carbohydrates, it will stimulate the pancreas to release insulin. In muscle, insulin causes carbohydrate uptake from the blood, but it will also increase muscle protein synthesis, just as leucine does. Although the thought that carbohydrates might assist leucine in maximizing muscle protein synthesis, research has shown carbohydrates offer no additive benefit compared to leucine alone.3

In the case of low carbohydrate intake, such as when one is following a low-carb diet, with high levels of leucine in the blood, the insulin release caused by leucine will activate the muscle protein synthesis pathway despite the lack of carbohydrates.4 So, leucine’s ability to increase muscle protein synthesis comes from being absorbed into the muscle from the blood and by also stimulating insulin release. As a result, supplementing the diet with leucine has become fashionable to increase the availability of leucine to support muscle function. The reason to share these mechanistic roles of leucine is to help with the understanding of its vital importance in driving muscle metabolism.

The quest for finding ways to improve leucine effectiveness is ongoing. Enhancing the absorption of leucine into muscle can play an essential role in promoting muscle performance and health. Several different nutrients have been studied to determine their potential to improve leucine’s absorption and effectiveness. One such novel approach examined the effectiveness of utilizing methylsulfonylmethane (MSM) to improve leucine absorption. Adding MSM to the diet has been found to enhance nutrient, particularly leucine, absorption. MSM itself is a natural organic sulfur-containing compound often used for its ability to reduce inflammation. U.S. Made OptiMSM is the only MSM generally recognized as safe (GRAS) and is well-tolerated.11 As a result, studies have shown that 3 grams of OptiMSM can reduce inflammatory markers and minimize muscle damage following intense exercise.5,6 Interestingly, MSM also decreases the ability of the hormone, cortisol, to cause muscle protein breakdown in response to stress from strenuous activity.7

Probably of more interest to the athlete or to the person who enjoys exercising, is MSM’s ability to enhance amino acid absorption. Studies on OptiMSM show it is absorbed less than an hour after ingestion.8 As a result, oral supplementation of MSM has been studied to determine its effects on amino acid absorption into the blood after ingestion. A study using OptiMSM found that as little as 2 grams, when ingested with protein, was effective at enhancing leucine absorption greater than just the protein alone.9 The study found that OptiMSM increased leucine’s uptake for use by the body by a significant 12-13%. The enhanced leucine remained elevated by about 10% over the average for three hours after ingestion, which has profound implications for promoting healthy muscle metabolism because increases of leucine in the blood correspond to increases in muscle leucine 10. Therefore, the combination of protein with MSM can very likely improve the gains and effects one has as a result of training.

Based on what we have discussed here, it seems wise that to maximize the results of your workouts, include at least 2 grams of MSM along with your healthy diet. Finally, based on the benefits of MSM for reducing inflammation and preventing protein breakdown, and its ability to increase leucine absorption in the blood, MSM supplementation appears to be an advantageous strategy for safely magnifying the effectiveness of leucine on muscle performance and health.



1. Macnaughton LS, Wardle SL, Witard OC, McGlory C, Hamilton DL, Jeromson S, Lawrence CE, Wallis GA, Tipton KD. The response of muscle protein synthesis following whole-body resistance exercise is greater following 40 g than 20 g of ingested whey protein. Physiol Rep. 2016 4(15). doi: 10.14814/phy2.12893.

2. Cholewa JM, Dardevet D, Lima-Soares F, de Araújo Pessôa K, Oliveira PH, Dos Santos Pinho JR, Nicastro H, Xia Z, Cabido C.E., Zanchi NE. Dietary proteins and amino acids in the control of the muscle mass during immobilization and aging: role of the MPS response. Amino Acids. 2017 49:811-820.

3. Churchward-Venne TA, Pinckaers PJM, Smeets JSJ, Peeters WM, Zorenc AH, Schierbeek H, Rollo I, Verdijk LB, van Loon LJC. Myofibrillar and mitochondrial protein synthesis rates do not differ in young men following the ingestion of carbohydrate with whey, soy, or leucine-enriched soy protein after concurrent resistance- and endurance-type exercise. J Nutr. 2019 149:210-220.

4. Greenhaff PL, Karagounis LG, Peirce N, Simpson EJ, Hazell M, Layfield R, Wackerhage H, Smith K, Atherton P, Selby A, Rennie MJ. Disassociation between the effects of amino acids and insulin on signaling, ubiquitin ligases, and protein turnover in human muscle. Am J Physiol Endocrinol Metab. 2008 295:E595-604.

5. Kallman DS, Feldman S, Scheinberg AR, Kreiger DR, Bloomer RJ. Influence of methylsulfonylmethane on markers of exercise recovery and performance in healthy men: a pilot study. J Int Soc Sports Nutr. 2012, 9:46.

6. van der Merwe M, Bloomer RJ. The influence of methylsulfonylmethane on inflammation-associated cytokine release before and following strenuous exercise. J Sports Med. 2016,

7. Sp N, Kang DY, Kim DH, Lee HG, Park YM, Kim IH, Lee HK, Cho BW, Jang KJ, Yang YM. Methylsulfonylmethane inhibits cortisol-induced stress through p53-mediated SDHA/HPRT1 expression in racehorse skeletal muscle cells: A primary step against exercise stress. Exp Ther Med. 2020 19:214-222.

8. Krieger DR, Schwartz HI, Feldman R, Pino I, Vanzant A, Kalman DS, Feldman S, Acosta A, Pardo P, Pezzullo JC. A pharmacokinetic dose-escalating evaluation of MSM in healthy male volunteers; Miami Research Associates: Miami, FL, USA, 2009; pp. 1–83.

9. Data on File. Bergstrom Nutrition. Kreiger DR, Schwartz HI, Hernandez M, Pino I, Vanzant A, Parakso L, Acosta A, Caso J, Salzman R, Kalman D. A prospective, pilot clinical trial to evaluate the effects of MSM on amino acid absorption in healthy adults. Miami Research Associates: Miami, FL, USA, 2015; pp. 1–216.

10. Mitchell WK, Phillips BE, Williams JP, Rankin D, Lund JN, Smith K, Atherton PJ. A dose- rather than delivery profile-dependent mechanism regulates the “muscle-full” effect in response to oral essential amino acid intake in young men. J Nutr. 2015 145:207-14.

11. Butuwan M, Benjamin RL, Bloomer RJ. Methylsulfonylmethane: applications and safety of a novel dietary supplement. Nutrients. 2017 9:290.