L-Lysine and Animals

• According to the University of Michigan Healthwise Knowledgebase, high amounts of lysine have been linked to increased risk of gallstones and elevated cholesterol in animals.
  
  

L-Lysine and Humans

• When people take lysine at supplemental levels, consistent problems have not been reported. However, abdominal cramps and transient diarrhea occasionally have been reported at very high intakes (15 to 40 grams per day).
  
  

L-Lysine Use

• Lysine often is used to treat herpes viral infections. The University of Maryland Medical Center recommends 3,000 to 9,000 milligrams each day, in divided doses, to treat symptoms. For prevention, the recommendation is 500 to 1,500 mg each day, in divided dosages.
  
  

Drug Interactions

• The University of Michigan does not note any drug interactions with L-lysine. The University of Maryland Medical Center recommends that you not take L-lysine with arginine (another amino acid), because the two share common pathways in the body and excess arginine may lower L-lysine levels.
  
  

Taking L-Lysine

• Unless you are a serious athlete or a vegan who does not eat enough protein, you probably get enough lysine in your diet. A health care provider can help you determine if taking L-lysine might be beneficial.