1. Home > 
  2. Dog Supplies > 
  3. Food Supplements > 
  4. Lysine Products > 
  5. Tomlyn L-Lysine Immune Support > 
  6. Tomlyn Immune Support L-Lysine Supplement Powder for Cats (3.5 oz)


Tomlyn Immune Support L-Lysine Supplement Powder for Cats (3.5 oz)

Item: 433343
1. Select type:
2. Select size:
This item is currently out of stock!


Tomlyn Immune Support L-Lysine Supplement Powder for Cats provides support to your cat's immune system and eye health.

If your cat suffers from an upper respiratory infection or from feline herpes then providing your cat with l-lysine can prove essential to their well-being. This amino acid contributes to the relief of eye irritation, cold sores, sneezing, difficulty breathing and more.

Tomlyn® Immune Support L-Lysine Supplement Powder for Cats includes 500 mg of l-lysine hydrochloride per scoop to provide an ample amount of the nutrient for cats in need of relief. This powder also features a palatable chicken and fish flavor that makes it easy to administer to your feline. If your cat suffers from the eye, immune, or respiratory problems, then try l-lysine to alleviate his or her ails today!

Key Features:
  • Veterinarian formulated trusted since 1976
  • Supports a healthy immune system and normal eye health and function
  • Tasty chicken and fish flavor
  • Ingredients

    Active Ingredients per Scoop: L-lysine Hydrochloride (500 mg)

    Inactive Ingredients: Brewer's Dried Yeast, Dried Whey, Hydrolyzed Fish (enzymatic), Hydrolyzed Poultry Liver (enzymatic), Lecithin, Mixed Tocopherols (a preservative), Rosemary Extract, Sodium Acid Pyrophosphate, Soybean Oil.

    Useful Information

    Cautions: Safe use in pregnant animals or animals intended for breeding has not been proven.

    If animal's condition worsens or does not improve, stop product administration and consult your veterinarian.

    For Use in Cats Only
    For use in cats only. Recommended for immune system support and conditions responsive to L-lysine.

    Directions for Use: Sprinkle over dry food or mix with a small amount of canned food.

    For cats and kittens under 6 months: ½ scoop given 2 times daily.
    For cats 6 months and older: 1 rounded scoop given 2 times daily.

    WARNINGS: For animal use only. Keep out of reach of children and animals. In case of accidental overdose, contact a health professional immediately. Store in a cool, dry place.

    Made in Canada.

    Customer Reviews

    Review Summary
    11 Reviews
    73% (8)
    9% (1)
    9% (1)
    0% (0)
    9% (1)
    91% Recommend this product (10 of 11 responses)
    By H859 H.
    June 12, 2021
    Very helpful tool when caring for feral, stray, or outside cats. Noticeably reduces the effects of viruses associated with the eyes and sinus. The cats eat the food with the lysine as well as they do without. Very good product.
    By Terry42
    Salisbury, Md.
    Easy To Administer
    December 24, 2018
    "Miss Puddin" is quite particular when it comes to accepting any kind of supplement to her fine dining but the L-Lysine Powder blends in perfectly with her food and she has never rejected it. Much easier than pills.
    • Healthful supplement.
    • None.
    By 4cats2dogs
    Olympia, WA
    Healthier than other brand so better value
    December 13, 2016
    I am about to buy yet another Tomlyn Immune Support L-Lysine Supplement Powder for our cats. I was tempted to buy the other brand (Felisyl) since it seems cheaper but then I noticed this Tomlyn brand is 500mg of L-Lysine per scoop so it's twice as concentrated plus the Felisyl has unhealthy additives like sugar where this Tomlyn has healthy additives like brewer's yeast. It makes sense why the very picky healthy pet store by me also carries this Tomlyn brand. I promise I don't work for any of these guys. I'm just wanting cat owners to get the best product for their kitties. Two of our four cats have immune weaknesses due to Feline herpes and this has been a great solution, way better than the treats of various brands we used to get. (They would like the treats when the bag first was opened then even a few days later would loose interest.) I sprinkle one scoop/cat onto their wet food, 1 scoop each morning. For a while at first I did mix it in as I was nervous. I don't even have to mix it in anymore, it's sprinkled right on top.
    By cammurk
    Munising MI
    great product
    November 7, 2016
    not only do I use this product for my own cat, who has an on going issue with sneezing, I use it for foster kittens and mommas in my care
    By Mo
    It's like a treat
    October 28, 2016
    One of the kitties LOVES this, he thinks it's a treat!
    By Sassy
    Good price!!
    June 6, 2016
    I've bought same size product elsewhere and it was more expensive. This is a good buy!
    By CatDogMom
    chicago, il
    Easy to put in wet food- my picky cats like it
    March 17, 2016
    We have four cats and of course the two that are pickier eaters need to get Lysine every day because our vet says they both have the Feline herpes virus. Our history: So we had tried the Lysine chewable treats (several brands) but one only ate them when the bag had just been opened and they were at their smelliest, and the other wouldn't touch them. We had resorted to grinding up the treats w/a mortar and pestle (since we had bought several bags) to hide the hard treats in their wet food. This powdered Tomlyn Immune Support L-Lysine Supplement Powder for Cats fixes those problems. It's already powdered and just a teeny level scoop (scoop provided) gives them 500mg which is what they need in a day. Since it's so easy to give we have been giving it without fail and one of the cats is noticeably more energized and has a better appetite. The other has no more runny eye because as I said this is so easy to give we definitely do it every day, mixing it in their wet food.
    By RcansawTraveler
    December 29, 2015
    been using lysine for my rescue cats for several yrs now. they all come in with URI. by adding lysine to their diet I see a much improved health such as watery eyes disappear, sneezing stops & I know their immune system is being improved. takes a few days to notice the improvement but they are always so sick when they come in. U can't beat the price and so much cheaper than other brands for a natural product to help fight against URI.
    By Rabbit78
    Bonita Springs, FL
    peace of mind
    November 29, 2015
    I bought this based on the advice of a coworker whose cat also has FHV. My vet had given me the lysine gel, which was a pain to always swab onto his fur for him to lick off. The powder is easy to mix into his food, he doesn't even notice it, and his FHV sneezing fits and eye issues cleared up within a few days. When I reduced the dosage to once a day and he had a flare up, just adding it to a 2nd meal quickly made his eye clear up.

    This was well worth the price, seems like it will last a long time, even using it twice daily, and it arrived quickly. For the peace of mind it has given me and the effectiveness of the product, I would definitely recommend this to everyone having to deal with FHV.
    By AzCatLover
    Cat doesn't like it
    October 11, 2015
    My cat doesn't like the fishy smell and won't go near anything with this power or on in it. Tried sprinkling it on his dry food; he then stopped eating dry food completely. Tried mixing it in his wet food, he sniffs and walks away. Won't take it in liquids either. Might trip mixing a little in Catsip milk to see if he might take it that way since I have the whole jar of powder left and Catsip milk is sweet (and almost lactose free so doesn't bother their digestive tracts). If your cat will take it, a little of the powder goes a long way so it would last quite a while..tiny measuring spoon comes with the powder. There are gel versions that might work better for picky eaters like my cat. For example, I use a high calorie protein gel for my senior cat who lost weight, (some of these type gels do have L-Lysine in the ingredients, you just have to read the labels) putting a dab on a q-tip and placing the gel on his tongue or inside cheek so he HAS to eat it. I hate having to force my cat to take something though, even when it is for his own good. Cat just won't do this powder so far, smells it instantly and turns up his nose and walks away, so unfortunately don't know if it works.
    By JLJ
    No seal on product
    September 28, 2015
    I've used this brand for a long time, and this was the first time it arrived without a seal. I used it anyway and hope it is okay.
    I can't really tell if it is helping my cats or not.

    Questions and Answers

    1 Question & 4 Answers
    March 5, 2019
    Could this product cause an increase in thirst in an older 12 year old cat? I've been using this product for a few weeks and have noticed my cat seems to be drinking a lot more water. Thank you.
    4 Answers
    I've had my cat on this product for eight years and she has shown no ill effects or excessive drinking.  If a cat does drink more water, it’s actually beneficial for the kidneys. A quick call to your vet will ease your mind.
    Submitted by: Sally51 on March 6, 2019 from Chesterland, OH
    I've been using this product on two of my cats for about 2 years and they have no issues with drinking more water. Since your cat is older I agree with Sally51, please contact your vet. I have had 4 cats that were diagnosed with feline diabetes. They would drink water as if they could not get enough. I hope it's not that serious, but I would ask the vet.
    Submitted by: HappyKittyMom on March 7, 2019 from Alabama
    I don’t know that this product is to promote more drinking or thirst in cats. This is not an effect in my cats.It is a supplement for immune support for feline herpies. Excess thirst may be a sign of kidney issues. 12 year old cats need to be monitored for kidney disease and other senior health issues. Check with your vet. Hope this is helpful. Jane  
    Submitted by: Teakmom on March 8, 2019 from Seattle
    Hi Carsguy, this is should not cause your cat to drink more water. I would contact you vet since your cat is a older cat just to make sure that there are no other issues that are causing your cat to drink more water.
    Submitted by: EntirelyPets on April 29, 2019

    Tomlyn Immune Support L-Lysine Supplement Chews for Cats (30 Count)Tomlyn Immune Support L-Lysine Supplement Chews for Cats (30 Count)Reg price: $22.99
    Sale price: $16.99