Nothing at all. I legit completely got rid of it. I use zero light therapy on my lips since February 2021. Though I really should use it because I often have dry/chapped lips and light therapy would help with that. But for cold sores, I don't do anything anymore. No protocol. No routine. I wrote about it a bit below. I pointed red & far red light at the source of the inflammation instead of the lips, one singular time. For 15 minutes. And 20 years of agony was gone overnight.

https://ionizer.substack.com/p/light-therapy-to-cure-cold-sores

Before February 2021, I did use a device called virulite (fda approved) https://www.amazon.com/Virulite-Approved-Invisible-Electronic-Treatment/dp/B003HUP4TM for a few years. I do not recommend this product. It does work but it's so over priced and very weak. And literally any laser diode works 100x better. With red light laser, I would get rid of the cold sore within the same day. With the virulite device, it would take a few days.

Further, I am huge on treating the symptoms and the underlying cause in any inflammation. Your skin inflammation for example could be caused by air pollution, chemical sensitivity, unfiltered shower water, a latent virus, or something else. One of the most unique things about me and light therapy is that shockingly, I don't actually want to use it. I want to actually cure and heal my body period. I hate relying on anything in life. I also trust the body. That's what light therapy is about, giving your body energy at the local cellular level to overcome inflammation. So if you commented and told me you have light therapy devices that work perfect, that still isn't enough for me to hear. The goal is for you to use nothing at all. Your skin should not be under any state of inflammation or duress from simply existing. Maybe it sounds corny but it's what I believe in.