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L-Lysine — Frequently Asked Questions

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Frequently Asked Questions

Does L-Lysine really help with cold sores?

Clinical evidence suggests it can. A 1987 RCT found 1 g lysine three times daily significantly reduced herpes simplex recurrence and severity. The mechanism is competitive inhibition of arginine, an amino acid HSV needs to replicate. For prevention, 500-1000 mg daily is commonly used; during active outbreaks, 3 g/day is typical. Results vary between individuals.

Can I take L-Lysine and L-Arginine together?

They have opposing effects regarding herpes — lysine inhibits HSV replication while arginine may promote it. If taking lysine for cold sore prevention, avoid high-dose arginine supplementation. For general health, moderate amounts of both from food are fine. If using both as supplements, take them at different times of day.

How much L-Lysine should I take daily?

For general health, 500-1000 mg daily is sufficient. For herpes prevention, 1-3 g daily is the studied range. During active cold sore outbreaks, up to 3 g daily in divided doses has been used. The RDA for lysine is about 38 mg/kg body weight, easily met through a diet containing adequate animal protein.

Full L-Lysine Guide

References

  1. (). Success of L-lysine therapy in frequently recurrent herpes simplex infection. Dermatologica. DOI
  2. (). Dietary L-lysine and calcium metabolism in humans. Nutrition.
  3. (). Oral treatment with L-lysine and L-arginine reduces anxiety and basal cortisol levels in healthy humans. Biomedical Research. DOI