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What is L-Lysine?

N.M. Shanley
N.M. Shanley

L-Lysine is an essential amino acid that is available as a nutritional supplement. It helps the body absorb calcium, and supports the creation of collagen. Evidence suggests that lysine may help treat cold sores and help prevent osteoporosis.

Amino acids such as L-Lysine are required to maintain good health. These acids are not manufactured by the human body. People get their required amount of amino acids from food, nutritional supplements, and herbs. Natural sources of this amino acid include red meat, chicken, fish, eggs, tofu, and legumes, such as beans and peas.

L-Lysine is linked to the production of carnitine. Carnitine converts fatty acids into energy, which in turn reduces cholesterol in the bloodstream. Lysine has also been used to treat cold sores.

L-Lysine can be found naturally in red meat.
L-Lysine can be found naturally in red meat.

Several studies were completed to test the effectiveness of taking these supplements on a regular basis to control cold sore and genital herpes outbreaks. These studies had mixed results. While some groups concluded that this supplement prevented outbreaks, other studies showed that the Lysine supplements had no effect on the duration or timing of outbreaks.

L-lysine is often taken as a supplement.
L-lysine is often taken as a supplement.

Since it is connected to the production of collagen, athletes sometimes take lysine supplements. Collagen builds connective tissues and helps the human body maintain lean muscle tissue and burn fat. No major studies support this use of the lysine supplement.

People with an L-Lysine deficiency can suffer from nausea, fatigue, dizziness, and other common flu-like ailments. Fertility issues may surface as well, if not enough L-Lysine is present in the body. Women who have trouble conceiving can talk to their doctor regarding supplement use.

Lysine supplementation might be beneficial, but there also are a few possible side effects.
Lysine supplementation might be beneficial, but there also are a few possible side effects.

Health-conscious people can supplement their L-Lysine intake with tablets or liquid. Lysine is also available as a cream that can be used to treat a cold sore or herpes outbreak in progress. Patients taking any medications should consult a doctor prior to taking supplements, as negative drug interactions are possible.

Too much Lysine in the body can cause problems also. Excessive use of lysine can cause cramps, nausea, and diarrhea. Extremely high levels of lysine can increase cholesterol and triglycerides in the bloodstream.

Overuse of lysine can cause diarrhea and stomach cramps.
Overuse of lysine can cause diarrhea and stomach cramps.

There was also one report of kidney disease in a patient who took lysine supplements. People can stop taking lysine immediately and see a doctor to help alleviate these symptoms. Pregnant women and those who are breastfeeding may not want to take this supplement. Not enough is known regarding the safe use of Lysine in pregnant women and nursing mothers.

Discussion Comments

KaBoom

@sunnySkys - A lot of supplements advertised in commercials aren't exactly proven to be effective.

However, even if L-Lysine doesn't work the way it is supposed to, your friends may be experiencing a placebo effect. They take the supplement, convinced that it will work. So their body is convinced too, and no more cold sores! Even though the L-Lysine didn't really do anything.

sunnySkys

For some reason I was sure the studies about L-Lysine and cold sores was conclusive. I have two friends that take this supplement for cold sores and they say it works well. Also, the commercials I've seen definitely make it seem like L-Lysine has been completely proven to work.

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    • L-Lysine can be found naturally in red meat.
      By: Artyshot
      L-Lysine can be found naturally in red meat.
    • L-lysine is often taken as a supplement.
      By: compuinfoto
      L-lysine is often taken as a supplement.
    • Lysine supplementation might be beneficial, but there also are a few possible side effects.
      By: Steve Silver Smith
      Lysine supplementation might be beneficial, but there also are a few possible side effects.
    • Overuse of lysine can cause diarrhea and stomach cramps.
      By: Johan Larson
      Overuse of lysine can cause diarrhea and stomach cramps.
    • Lysine can be used to treat cold sores.
      By: uwimages
      Lysine can be used to treat cold sores.
    • Tofu is a great natural source of L-Lysine.
      By: Jiri Hera
      Tofu is a great natural source of L-Lysine.