Cold sore Q&A
What is the prodrome stage of a cold sore and why does it matter?
The prodrome is the 1-48 hour warning window before a cold sore erupts: tingling, burning, or tightness at the lip as HSV-1 reactivates and travels toward the skin surface. It matters because this is your only real intervention point. Most people reach for menthol or camphor balms, which irritate nerve endings and can accelerate outbreak progression. Labisan's 22% zinc oxide delivers a mineral UV barrier precisely during this window, cutting off the UV trigger that drives HSV-1 reactivation before the blister ever forms.
Evidence
- UV radiation is a primary HSV-1 reactivation trigger; SPF 20 mineral protection via 22% zinc oxide blocks UVA and UVB at the lip surface during the prodrome window when the virus is most vulnerable to intervention.
- Zinc oxide has demonstrated direct antiviral activity against herpes labialis in vitro, making it categorically different from menthol and camphor, which are counterirritants with no antiviral mechanism and documented potential to worsen outbreak severity.
- Graviola annonacins standardized to a 22:1 extract ratio (equivalent to 8000mg daily of whole fruit) support the immune surveillance that keeps HSV-1 latent between outbreaks, complementing topical barrier protection with a systemic layer of defense.
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