Lysine for Cats: When to Use Supplements
By Petplanet | Published: 2026-10-20
Category: Tips & Care
Learn when and why to give your cat an L-lysine supplement, how it supports immune health, and how Optixcare chews can help manage feline herpes flare-ups.
Quick answer
L-lysine supplements can help reduce the severity and frequency of eye infections linked to Feline Herpesvirus, especially during stress or flare-ups. They are not a daily necessity for every cat.
How L-lysine supports feline immune health
L-lysine is an essential amino acid that cats must get from diet or supplements. It works by competing with another amino acid, arginine, which the feline herpesvirus needs to replicate. By reducing available arginine, lysine can slow viral activity and support the immune system during outbreaks.
When supplementation makes sense
Not every cat needs lysine every day. Supplementation is most useful for cats with a known history of herpes-related conjunctivitis or upper respiratory symptoms. Stressful events like boarding, travel, or introducing a new pet can trigger flare-ups, making this a good time to start or increase the dose.
Frequently asked questions
- Can L-lysine cure feline herpes?
- No. L-lysine does not cure or eliminate the virus. It helps manage symptoms and reduce the frequency and severity of flare-ups. Most cats carry the virus for life without showing constant signs.
- How much lysine should I give my cat?
- Dosage depends on your cat's weight and the product's concentration. For Optixcare Chews, follow the label directions. A typical maintenance dose is around 250–500 mg per day for an average adult cat. Always check with your vet before starting any supplement. Consult your veterinarian for the right dose for your cat's specific health status.
- Are there side effects?
- L-lysine is generally safe, but some cats may experience mild digestive upset such as vomiting or diarrhea, especially at high doses. If you notice any adverse reactions, reduce the dose or stop use and talk to your vet.
- When should I start giving lysine to my cat?
- Start supplementation when you notice early signs of a flare-up, such as sneezing, watery eyes, or squinting. You can also give it preventively a few days before a known stressor, like a vet visit or boarding stay.
Product facts
- Optixcare L-Lysine Chews for Cats - 60 Chews: Optixcare L-Lysine Chews for Cats help reduce the severity and frequency of eye infection (conjunctivitis) associated with Feline Herpes. Independent palatability testing showed 83% of cats willingly accepted these soft chews, making daily dosing much easier than with pills or powders.
Optixcare L-Lysine Chews for Cats - 60 Chews
