Remedy · supplement
Lysine
Also: L-lysine
An amino acid taken for cold sores — with conflicting trial evidence.
Evidence by condition
Each grade reflects the research for Lysine and that condition specifically.
- CCold sores
Some older RCTs (~1 g/day or more) reported fewer recurrences, but others and the Cochrane review found no benefit and rated the evidence very low quality; it does not speed healing.
2 citation s
- Success of L-lysine therapy in frequently recurrent herpes simplex infection: treatment and prophylaxis Randomized trial 1987 · n=52 · Dermatologica · PMID 3115841
- Interventions for prevention of herpes simplex labialis (cold sores on the lips) Systematic review 2015 · n=2,640 · Cochrane Database of Systematic Reviews · PMID 26252373 · DOI 10.1002/14651858.CD010095.pub2
- Success of L-lysine therapy in frequently recurrent herpes simplex infection: treatment and prophylaxis
Lysine is thought to counter the arginine that herpes virus needs to replicate. The trials disagree — some show fewer cold-sore recurrences at ~1 g/day, others (and Cochrane) show nothing — so it is a low-risk option of uncertain benefit, not a proven treatment.