Not really efficaceous: https://www.cochrane.org/CD010095/SKIN_measures-preventing-c...

My vet said the same (chronic respiratory problems in cats are often caused by feline herpesvirus). The effect on the cat is at best slight.

I'm not sure if anecdotes are allowed or welcomed, hope this is okay: Around 2003 I learnt about lysine having something to do with preventing HSV-1, so I got some and took some large doses until the bottle was finished. Haven't had a cold sore since, and I was getting them ~yearly before. Sometimes I can feel the tingling and think shiiit, here it comes again finally, but I never really had a proper breakout.

Also, the more I hear about the HSV/Alzheimer's link, the more I freak out about my shitty memory :(

> Sometimes I can feel the tingling

That's the viral shedding.

Correct. In case it was unclear, I didn't mean to imply that I'm "cured", only that I've never had an outbreak since then.

Only anecdotal, but yes.

Supplement before if I know I will be increasing UV exposure. e.g. visiting high desert

Visiting know stressful environment. (choose your own adventure)

Or if I think I might be starting to feel one coming on.

Outbreaks in the decades after are way down from outbreaks from the decades before, but please do remember correlation is not causation and becoming a person who can consider mitigation may be more significant then the particular ritual.

Oh and prescription anti-virals work wonders.

I used to supplement with a huge oversupply of lysine, enough that I could smell it on my skin, and taste it in my saliva. I could never detect any effect, whether shortening an outbreak, reducing severity, or preventing an outbreak. I have had to conclude that nerve cells that host the virus manage to keep excess lysine outside the cell.

A peanut or nut binge would definitely worsen an outbreak, though.

Oral acyclovir also has no effect on the strain(s) I have. I have had an outbreak start while taking acyclovir prophylactically, and proceed through the whole cycle.

Valacyclovir 1000mg still works. Initially, one tablet. Now, 2 or 3.

No (I think). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6461191/

Here is a nice round up of the known evidence: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6419779/

TLDR: "Longer duration controlled studies of daily lysine doses exceeding 1.2 g/d are required to definitively test its role in herpes simplex prophylaxis"

EDIT: After reading through the provided table, to me it seems that most studies show little to no evidence that Lysine doses help against the virus. It looks like it's mostly placebo. (Disclaimer, I am not a virologist, this is my take on the paper.)