Lysine for Herpes Simplex Prophylaxis: A Review of the Evidence

Integr Med (Encinitas). 2017 Jun;16(3):42-46.


Background: Herpes simplex virus (HSV) has been implicated in the etiology of recurrent aphthous ulcers, cold sores, and genital sores.

Primary study objective: To summarize the research evidence for use of L-lysine to prevent HSV disease recurrence, a use not widely recognized by doctors.

Methods/design: Two scientists conducted a literature search of EMBASE, Medline, AMED, and CINAHL for the expanded terms lysine and herpes simplex or HSV in the title field and then independently screened the abstracts for clinically relevant articles. Disagreements on article inclusion were discussed before the literature was reviewed to see whether lysine is effective for preventing herpes simplex relapse.

Intervention: Oral L-lysine supplements were taken daily.

Primary outcome measures: Described individually for each trial reviewed.

Results: L-lysine supplementation appears to be ineffective for prophylaxis or treatment of herpes simplex lesions with doses of less than 1 g/d without low-arginine diets. Doses in excess of 3 g/d appear to improve patients' subjective experience of the disease.

Conclusion: Longer duration controlled studies of daily lysine doses exceeding 1.2 g/d are required to definitively test its role in herpes simplex prophylaxis. Patients with cardiovascular or gallbladder disease should be cautioned and warned of the theoretical risks of lysine supplementation.

Publication types

  • Review