L-Lysine & Blood Pressure

Fact Checked

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Evidence does not suggest that lysine, an essential amino acid, has any effect on blood pressure — at least not directly. It may, however, improve cholesterol levels. High cholesterol can narrow arteries, which often increases the risk of high blood pressure as well as other cardiovascular conditions, such as heart disease, angina, heart attack and stroke. Therefore, taking a supplement containing lysine may be of some benefit but talk to your doctor before doing so.


A study published in the January 1983 “American Journal of Clinical Nutrition” shows that lysine increases carnitine levels in the blood. After given 5 grams of lysine orally, participants experienced an increase in plasma carnitine in as little as six hours. Levels continued to rise for a total of 48 hours. Carnitine converts fatty acids into energy, which may prove beneficial for lowering blood cholesterol, according to the University of Maryland Medical Center.


Another study published in the December 2008 “American Journal of Clinical Nutrition” supports the university’s claim, indicating carnitine promotes significant improvements in low-density lipoprotein levels. It appears this nutrient had the most impact on oxidized LDL levels, reducing numbers by over 15. Oxidized low-density lipoproteins increase the risk of cardiovascular disease. If lysine increases the plasma levels of carnitine, it stands to reason that it should also be of some benefit on cholesterol.

Blood Pressure

Although it doesn’t have a direct impact on blood pressure, the effect that lysine has on cholesterol could help eliminate at least one factor known to contribute to high blood pressure. If, however, high blood pressure isn’t a result of elevated cholesterol levels, this supplement won’t likely be of assistance. Instead, other methods are necessary to reduce blood pressure, such as reducing sodium intake to no more that 1,500 milligrams, losing weight or increasing your level of physical activity.


The recommended daily intake of lysine is primarily based on your weight. Therapeutic dosages are often set at 12 milligrams per kilogram of body weight. The more you weigh, the more lysine you will need to take. Talk to your doctor to best establish your dosage. Too much of this amino acid has been linked to an increased risk of gallstones and renal failure.