Herpes labialis
Not recommended
Monolaurin is a monoglyceride of lauric acid sold as a supplement for cold sores (herpes labialis), promoted for the antiviral activity it shows in lab settings. In people with cold sores it has not shown convincing benefit – there is no evidence base for this use. What actually helps during a flare are oral or topical antivirals such as aciclovir or valaciclovir, especially when started at the first signs. The substance itself is harmless in this role, but do not use it instead of treatment with proven benefit, or you may miss out on care that works.