Lysine, an essential amino acid, is an exceptionally important amino acid that’s indispensable to building quality muscle fast and it also has quite a variety of benefits.
Lysine promotes muscle growth
1) Lysine promotes muscle growth by promoting vasodilator (independently of nitric oxide) and enhance blood flow which aids in transporting nutrients to the muscles (R).
2) L-lysine suppresses the parathyroid hormone, which is antagonistic to the thyroid. This will promote thyroid function and boost muscle growth (R). A higher lysine diet also results in higher thyroid hormone, T3, which increases metabolic rate, protein synthesis, androgen production, etc… (R) Read here about the importance of thyroid for muscle growth.
4) Lysine increases cell proliferation (rapid increase in the number or amount of something, in this case, muscle tissue). It also speeds up wound healing (R) and increases angiogenesis which in turn increases vascular endothelial growth factors leading to the formation of new arteries which can then supply tissue with oxygen and nutrients to help it repair and grow.
6) Insulin is the primary driver of amino acids into muscle tissue, and lysine increases insulin, thus aiding in driving more amino acids into the muscle. (R) It’s best to take lysine with a meal as it also increases postprandial IGF-1.
7) Lysine is involved in histone modifications, which are very critical for regulating chromatin structure (the DNA molecules packaged by histone) and function. This, in turn, can affect many DNA-related processes, such as transcription, recombination, repair, replication, and chromosomal organization, which is essential for building quality muscle (R).
Lysine is probably the most important amino acid for build muscle as it is the building block for de novo syntheses of almost all proteins and many peptides.
8) Lysine together with arginine boosts growth hormone (GH) release. It’s also shown that 1.2-1.5g of lysine and arginine, increase growth hormone by 2.7-8 fold, but there was no rise in GH when either one was administered alone. (R, R)
There appears to be a synergy between arginine and lysine as when ingesting of 5-9g arginine alone, only increased growth hormone ∼2 fold. (R) Higher doses arginine isn’t very well tolerated.
9) Lysine potently lowers cortisol, which is catabolic when elevated chronically. The effect seem to be potentiated by L-arginine and just 2.64g of each per day for only one week was able to significantly lower cortisol (R).
10) L-lysine acts like a serotonin receptor 4 (5-HT4) antagonist, and prevent serotonin (5-HT)-induced anxiety, diarrhea, ileum contractions, and tachycardia and in stress-induced fecal excretion. (R) As a confirmation to the above-mentioned study that lysine+arginine lowered cortisol, 5-HT4 antagonists (like lysine) block cortisol secretion in the adrenal cortex (R).
Lysine also partially blocks 5-HT4 receptors in the heart and can thus increase contractile strength, while can be a major plus for exercise performance. (28)
Also, anything that decreases serotonin indirectly increases dopamine, and lower cortisol with higher dopamine will lead to higher testosterone.
Infants need much higher lysine than older children and adults, because of their need to grow. Muscle builders can thus also capitalize on this amino acid to speed up growth.
Lysine helps burn fat
Lysine is required for the synthesis of carnitine. In order to burn fat (particularly long chain fatty acids), your body needs carnitine to transport fatty acids into the mitochondria. The more carnitine, the more fatty acids can be transported and the more energy you can produce. Insufficient carnitine can lead to higher triglycerides, cholesterol, diabetes, etc…
Carnitine is synthesized from two amino acids, namely lysine and methionine and requires ascorbic acid, ferrous iron, pyroxidine (vitamin B6) and niacin (vitamin B3) as cofactors. (R)
Carnitine is also very important to provide fuel during exercise and plays additional physiological roles in protecting organisms from oxidative stress, promoting substrate oxidation in brown adipose tissue, improving cardiac performance, and regulating energy partitioning in the body (R, R).
a) Fish being the highest source, followed by beef, chicken, milk, etc
b) Arginine and lysine compete for uptake into cells, and excess arginine will disrupt lysine uptake in cells and vise versa. Due to this antagonistic action, lysine and arginine should not be taken together in high doses. As seen in these two studies, 1.2g each resulted in a rise in GH and in young men, but 3g each did not increase GH and IGF-1 in older men. (32, 33)
c) The benefit of taking an amino acid (such as in a supplement), is that is doesn’t have to be deaminated and hydrolyzed in the liver, thus saving a lot of energy and also doesn’t produce waste products such as with digestion of meats etc…
Lysine is pretty cheap on its own and very well absorbed. It would be best to take it with a protein meal. Start with 500mg daily and work up from there. At most consume 1.5g x3 daily. Then it would be important to cycle 3 days on, 3 days off, or take it only on training days.
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