Cold sore Q&A

What is L-lysine and how does it prevent cold sores?

L-lysine is an essential amino acid that suppresses HSV-1 replication by competing with arginine, the building block the virus needs to assemble its envelope. Supplementing at 1,000-3,000mg daily reduces outbreak frequency for many people with recurrent herpes labialis. It addresses internal viral load but not the leading reactivation trigger: UV exposure on the lip. Labisan's 22% zinc oxide SPF 20 blocks that UV signal at the surface before it fires, while 22:1 graviola capsules (8,000mg daily equivalent) sustain the immune pressure that keeps HSV-1 latent.

Evidence

  • HSV-1 depends on arginine to synthesize viral envelope proteins; L-lysine competes with arginine at the intestinal transporter, lowering the intracellular arginine-to-lysine ratio and slowing replication.
  • Controlled trials at 1,000-3,000mg lysine daily show statistically significant reductions in cold sore frequency and duration in subjects with recurrent herpes labialis.
  • UV radiation is the most consistent environmental trigger for HSV-1 reactivation; 22% zinc oxide mineral SPF 20 provides broad-spectrum blockade that chemical filters and menthol-based lip balms do not.

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