Cold sore Q&A

What causes cold sore outbreaks to keep coming back?

HSV-1 never leaves your body. After a primary infection the virus retreats into the trigeminal ganglion and reactivates whenever your defenses drop. UV radiation is the single biggest trigger: it suppresses local immunity in lip tissue and destabilises viral latency. Most lip balms make this worse by delivering menthol or camphor, which irritate already-compromised tissue. Mineral SPF with 22% zinc oxide physically blocks the UV trigger at source, while manuka oil and graviola annonacin work at the barrier and immune level to keep the virus dormant.

Evidence

  • UV radiation is the leading documented environmental trigger for HSV-1 reactivation in herpes labialis, acting by suppressing local T-cell immunity in perioral skin.
  • 22% zinc oxide delivers broad-spectrum physical UV blockade (SPF 20) with zero chemical penetrants, removing the top reactivation trigger without menthol or camphor irritation.
  • Manuka oil's methylglyoxal fraction shows in vitro activity against HSV-1 at the lipid envelope; Labisan applies it directly at the labial barrier where viral shedding begins.
  • Graviola annonacin at a 22:1 extract ratio provides the immune-equivalent of 8000mg daily fruit intake, supporting systemic defence during the latency-to-reactivation window.

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