Tomlyn Immune Support Powder Immune Supplement for Cats, 3.5-oz tub

Skip image gallery
Slide 1 of 7

At a Glance

  • Immune Support
  • All Lifestages

$12.58 First Time Autoship Price
this order
Save 40% (up to $20) today when you set up Autoship. 
$19.92 Autoship Price
(-5%) future orders
  • Keep saving 5% on every order
  • Get deliveries on your schedule
  • Skip, change, or cancel anytime
$20.97 Chewy Price
($6.00 /oz)
Save $0.02
$20.99 List Price
Promo, New Customers Only: Spend $49+, Get $20 eGift Card + Free Shipping with code: WELCOME
In Stock
FREE 1-3 day delivery on first-time orders over $35
Free 365-day returns

No interest if paid in full in 6 months on PayPal purchases of $149+. .

About This Item

Details

  • Features a high level of L-lysine at 500mg per scoop.
  • Helps manage conditions responsive to L-lysine, including upper respiratory problems, conjunctivitis and feline herpes.
  • Supports immune and respiratory health and helps maintain normal eye function.
  • Created in a highly palatable powder that makes administering to your feline friend easy and enjoyable.
  • Formulated by veterinarians, just one scoop per day contains the proper dose for your cat or kitten to stay in good health.

Ingredient Information

Instructions

FAQ

Learn More About Tomlyn From Our Team of Experts

Frequently bought together

Questions & Answers

23 Customer Questions

Where is the l-lysine for this sourced?

Answer by Chewy • Apr 12, 2020
Tomlyn sources their ingredients from mainly the United States and Canada, however some raw materials are sourced from China as that is the only location to obtain those raw materials.

How big is a "scoop?" Does a scoop come with the product?

Answer by Chewy • Feb 25, 2020
A scoop is equivalent to 1/8 of a teaspoon (0.52 grams). A scoop is included in the tub.

Why does the back of mine say only 1 scoop for cats 6months and older? But same 0.52gs per scoop

Answer by Chewy • Aug 14, 2019
It's directed that for kittens under 6 months get 1/2 scoop given 2 times daily. For cats 6 months and older get 1 rounded scoop given 2 times daily.

Can it be mixed with water and poured on dry food?

Answer by Chewy • Oct 05, 2022
This supplement is recommended to be mixed into dry or wet food. It is not recommended to mix in water.
Reviews
Write a Review
4.6
Rated 4.6 out of 5 stars
975 Ratings
Terms & Conditions

Customers Mention

Chewy identifies key considerations with the help of artificial intelligence and our veterinarians.

Effectiveness

91% Positive

Form and Administration

89% Positive

Ingredients

84% Positive

Nutritional Value

85% Positive

612 Customer Reviews

Rated 5 out of 5 stars
By Rey on Dec 16, 2025

Better alternative to chews

I used to give my cats the chewy lysine treats by smashing it up and adding to their food. They caught on eventually and refused to eat their wet food. I now add

I used to give my cats the chewy lysine treats by smashing it up and adding to their food. They caught on eventually and refused to eat their wet food. I now add this powder instead and they haven’t shown any resistance to it. It does have a chemical smell, but once I add it to wet food I no longer smell it. It has helped my cats herpes symptoms.

Rated 4 out of 5 stars
By KRISTIE on Feb 2, 2026

It's okay

My older 2 kitties don't mind it. Which MzLuna is Very Picky. So that is a Big plus. Much sure if it does what it says. Only reason it lost a star. Otherwise,

My older 2 kitties don't mind it. Which MzLuna is Very Picky. So that is a Big plus. Much sure if it does what it says. Only reason it lost a star. Otherwise, Happy Mama

Rated 5 out of 5 stars
By Alexandra on Jan 14, 2026

This works!

Anytime our cats seem to be having a minor cold or allergies (herpes flare up- runny nose or watery eyes), we sprinkle this in their wet food once a day for about

Anytime our cats seem to be having a minor cold or allergies (herpes flare up- runny nose or watery eyes), we sprinkle this in their wet food once a day for about a week, and their symptoms completely go away.

Rated 5 out of 5 stars
By MommyMom on Dec 25, 2025

My picky cat eats it

What I love about this product is my picky cat eats it . I’ve gotten something from the vet she would eat and I couldn’t stomach . She eats Tomlyn in her food

What I love about this product is my picky cat eats it . I’ve gotten something from the vet she would eat and I couldn’t stomach . She eats Tomlyn in her food with no issues . So do the cats I feed outside. This is a 10/10 for me.

Rated 4 out of 5 stars
By kaitlyn on Nov 19, 2025

Good vitamins

My cat will tolerate a half scoop on his food, but, not a whole scoop. It has a fish smell that my cat loves, but, he won't eat a whole scoop with his food. I just

My cat will tolerate a half scoop on his food, but, not a whole scoop. It has a fish smell that my cat loves, but, he won't eat a whole scoop with his food. I just use a half scoop . He has leukemia so, this helps his immune system. It's easy to use and lasts a long time. It's a very small scoop, so it lasts long and is worth the price

Rated 5 out of 5 stars
By Sadie on Jan 13, 2026

Manages symptoms well

This works well for managing feline herpes. It will not treat an outbreak, but helps with maintaining health to prevent outbreak

This works well for managing feline herpes. It will not treat an outbreak, but helps with maintaining health to prevent outbreak

Rated 5 out of 5 stars
By Deb on Sep 30, 2025

It worked!

My foster cat came to me with continual eye discharge. I gave it lots of time, thinking maybe she was stressed in new environment, but nothing changed. Finally

My foster cat came to me with continual eye discharge. I gave it lots of time, thinking maybe she was stressed in new environment, but nothing changed. Finally decided to try this, even tho I couldn't find good research on its benefits, so I was skeptical. BUT.... it worked for Pippi! It took a good 3 weeks but it worked!! No more eye discharge. At some point I'll stop giving it to her and see what happens... hoping her body can manage without it, but if not, it's worth the cost. I can sprinkle it on top of her wet food and she has no problem with it.

Rated 5 out of 5 stars
By Michelle on Oct 29, 2025

Keeps my cat healthy

My cat has been on immune support since he was a kitten due to health complications, he hated the brand I used to buy him so I decided to go for a something new

My cat has been on immune support since he was a kitten due to health complications, he hated the brand I used to buy him so I decided to go for a something new and tried TOMLYN, he can’t even tell the supplement is in his food and he has been as healthy as can be!

Rated 5 out of 5 stars
By Pam on Oct 17, 2025

Works great

Have used it for years. Have 4 cats and when they get sick this is what gets them over it. Don’t mess with putting it in food. Mix 2 scoops in a little water in

Have used it for years. Have 4 cats and when they get sick this is what gets them over it. Don’t mess with putting it in food. Mix 2 scoops in a little water in shot glass and give with medicine dropper. They don’t fight and this way I know each one is getting their full dose. Best medicine for cats immune.

Rated 3 out of 5 stars
By Sabrina on Jan 10, 2026

I haven’t seen a difference in health benefits

They don’t mind the taste so I still give to them not sure what it’s doing but hopefully it’s good for them

They don’t mind the taste so I still give to them not sure what it’s doing but hopefully it’s good for them