For both people and cats, L-lysine is a way to manage and control herpes effectively. This amino acid is present in every cat's body, but some cats do not have enough of it to ward off infections and illnesses.

Does lysine really work for cats?

Results. There is evidence at multiple levels that lysine supplementation is not effective for the prevention or treatment of feline herpesvirus 1 infection in cats. Lysine does not have any antiviral properties, but is believed to act by lowering arginine levels.

How long does it take lysine to work in cats?

Lysine is given by mouth in the form of a powder, crushed tablet, chewable tablet, or paste/gel. Mix the powder in a small amount of food unless otherwise directed. This medication can take up to a few weeks before full effects are noted, but gradual improvements are usually noticeable after a few days.