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  6. 6-PACK Felisyl L-Lysine Immune System Support Granules for Cats (21 oz)


6-PACK Felisyl L-Lysine Immune System Support Granules for Cats (21 oz)

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Felisyl is a supplement that contains the amino acid L-Lysine for use in cats and kittens for conditions responsive to L-Lysine. L-Lysine is an essential amino acid, which means that your cat's body needs it, but can't produce it, so this supplement is a perfect choice to provide that necessity.

L-Lysine HCL Immune System Support for Cats helps keep your cat healthy by supporting the immune system naturally so that it can function normally and produce antibodies. Felisyl L-Lysine HCL Immune System Support for Cats also helps maintain healthy tissue, supports respiratory health, and may even help with your cat's vision. The L-Lysine is in palatable poultry, and the flavored fish base was making these granules easy to give to your cat, sprinkle over or mix with food.

Key Benefits:

  1. Enhanced Immune Function: Lysine is an essential amino acid that plays a crucial role in supporting the immune system of cats. Felisyl L-Lysine granules provide a concentrated source of L-Lysine, which helps strengthen the immune response, making cats less susceptible to various viral and bacterial infections.
  2. Cold Sore and Feline Herpes Relief: Lysine is commonly used to manage feline herpes virus (FHV-1) infections, which can cause symptoms such as cold sores, sneezing, watery eyes, and nasal discharge in cats. Felisyl L-Lysine granules help alleviate these symptoms and reduce the severity and duration of FHV-1 outbreaks.
  3. Support for Respiratory Health: FHV-1 infections often affect the respiratory system in cats. By boosting the immune response and reducing viral replication, Felisyl L-Lysine granules can help improve respiratory health, decrease congestion, and alleviate breathing difficulties associated with respiratory infections.
  4. Minimizes Lysine Deficiencies: Some cats may have dietary deficiencies or require additional lysine due to various factors, such as stress, poor appetite, or certain medical conditions. Felisyl L-Lysine granules ensure an adequate supply of lysine, which is essential for the production of proteins, enzymes, and antibodies, thereby supporting overall feline health.
  5. Palatable and Easy to Administer: Felisyl L-Lysine granules are typically flavored to be palatable for cats, making them easier to administer. The granules can be sprinkled over food, mixed with wet food, or given directly to the cat. This convenience allows for hassle-free supplementation.

It's important to note that while Felisyl L-Lysine Immune System Support Granules provide valuable support for feline health, it's always recommended to consult with a veterinarian before starting any new supplement regimen for your cat. They can provide specific guidance tailored to your cat's individual needs and overall health.

Immune Support for Cats

Fuel your pet with the supplements they need to remain healthy and boost their immune system with cat health supplements that add much-needed nutrients and amino acids to continue being active.


L-Lysine is an essential amino acid that your pet?s body doesn?t produce, so this supplement is the perfect aid that helps support your pet?s immune system so that it can function normally and produce antibodies. L-Lysine also helps maintain healthy tissue supports respiratory health.

Pet Health Supplement

A healthy immune system and eye health are essential for cats of any age. Ensure your furry friend remains active with healthy vision with these pet health supplements that help support normal inflammatory response and help support cat-eye health.


Guaranteed Analysis (Per 1cc Scoop):
L-Lysine HCI 250mg


L-Lysine in a palatable base

Useful Information

Approximately 250mg of L-Lysine per one rounded scoop (322mg)

Kittens under 6 months: ½ Scoop twice Daily

Cats older than 6 months: 1 scoop twice daily

Store in a cool, dry place, out of the reach of children. Keep tightly shut to preserve freshness.

Customer Reviews

Review Summary
12 Reviews
75% (9)
17% (2)
8% (1)
0% (0)
0% (0)
92% Recommend this product (11 of 12 responses)
By Nicole
Good product at the best price
April 21, 2017
Can't find this stuff any cheaper! It pays to buy in bulk. My cats haven't had any herpes issues since they started taking this
By Meezer3
Chicago, Il
Important for all cat owners to be aware
January 18, 2016
According to our Vet Ophthalmologist, 85 % of all cats are infected with the Herpes virus that can cause devastating effects to their eyes. Many only carry it and show no signs, while others actively break with the disease often while under stress. One of our cats is such a animal.
Our Vet suggested we feed all our cats this supplement that can help their immune system keep the viruses growth in check and bolster their immune system. I have advised all my friends to use this powder in their cats food daily. I have owned Siamese cats for 42 years, and have been feeding this supplement for years now and I feel it helps them to stay healthy.
By Lynn
Love This Product
October 31, 2015
I have ordered the Felisyl many times, it truly makes a difference for cats with upper respiratory.
By iluvcats
Felisyl granules are the best
September 4, 2015
Felisyl granules are by far the best to use, in my opinion. It mixes well with wet food. The tiny granules are very palatable, unlike the paste that has a very strong seafood scent. I'm very pleased with this product and will continue buying it.
By Dixie S.
May 19, 2015
The cats took a bit of getting use to it after having Viralys for so long. It is not lasting quite as long as the Viralys, but cost wise it is much better. I will buy it again.
By peacherooo
Oriskany, NY
this works
May 2, 2015
I highly believe that this product helps my cats get over sneezy/watery eyes. I simply put a scoop into their canned food and they eat it right up. In less than a week they are back to normal.
By Blanca58
Houston, Tx
March 15, 2015
Just started using this, but my cat accepts it very well. I have been using another brand and will know better later if I see a difference in her well being.
By Frauline
Wonderful Product, Good Value
February 28, 2015
I purchased two of the powder form Felisyl supplements for my Sabrina. At first I never even heard of this nutrient until my Sabrina had a second go around with an eye issue. This time our Vet diagnosed her with Feline Herpes. Being a fairly new cat parent I am learning lots about cats. I am very pleased with this powder and my Sabrina doesn't seem to mind the "taste or slight yeasty scent" at all. I just mix it around in her wet food and she's good to go! I will definitely be purchasing again from Entirely Pets. From the moment I placed my order, my order confirmation email came right through with tracking shortly thereafter.I literally had my order in two days - regular shipping (I'm from NY). Oh, BY THE WAY... I noticed in some earlier reviews BEFORE placing my order that for some reason customers weren't receiving the "tiny" measuring spoons in with the product. I guess I was lucky and did. However, upon testing the tiny measuring spoon given with the product, it's the exact same measurement as an 1/8 measurement spoon.
By I n.
North Carolina
Review for 6-PACK Felisyl Immune System Support Granules (21 oz)
June 16, 2013
Have used this before. It helps the immune system in kitties.
By Karen
Outer Banks, NC
My Cats Love This
April 1, 2013
I have several rescued cats that take l lysine. This is the one product that they all love, I can just sprinkle it on their food and down it goes. One kitty won't even eat unless her food has it! highly recommend
By Kat
Delmar MD
Felisyl Powder
December 20, 2012
I have four indoor kitties and we were constantly having upper respiratory infections. My vet suggested that I put them on Llysine to help with the symptoms. The cost was exorbitant to say the least. So I started looking around and found Entirely Pets.

Felisyl is the best supplement I have ever given my kitties. They get 500ml daily and love the flavor. I actually have a kitty that wants to eat it right out of the cannister.

Way to go Entirely for offering such great products!
By Rae
Memphis, TN
It really makes a difference!
April 27, 2011
My Siamese cat has a bad case of herpes, because she was left untreated for so long before she was adopted which means she will always show some symptoms no matter how good the medicine is. We tried other brands of lysine powder and pastes that cost more money than the Felisyl, such as Viralys. None of them made the difference that Felisyl made for our cat. She has less frequent eye watering and sneezing compared to the other brands. She seems happier and more full of life!

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