In this review published in 2017 researchers found insufficient evidence for use in management with doses of less than 1 g/day. However after the authors reviewed findings from 1 small double-blind, randomized, placebo-controlled trial that suggested doses above 3 g/day may reduce recurrence rates and improve patients’ self-reported symptoms, warranted further study as supplementation was well tolerated.
References:
Mailoo VJ, Rampes S. Lysine for Herpes Simplex Prophylaxis: A Review of the Evidence. Integr Med (Encinitas). 2017 Jun;16(3):42-46. PMID: 30881246; PMCID: PMC6419779. https://pubmed.ncbi.nlm.nih.gov/30881246/