Uses/Benefits The most predominant benefit of L-lysine is for treatment of mouth and genital lesions caused by herpes simplex virus, as well as shingles caused by herpes zoster viruses. Taking L-lysine can speed recovery time and reduce the chance of recurrent breakouts of herpes infection. It’s important to note that the effects of taking L-lysine on a regular, long-term basis are not known. Good results can be seen by initiating supplementation during the beginning phases of a herpes simplex episode.Lysine is also used as a neutralizer for analgesic antipyretics such as acetylsalicylic acid and ibuprofen and for the synthesis of antihypertensive agents. Other uses include parenteral and enteral nutrition and as a component of sports nutrition products. .