

🐾 Keep your cat thriving with every lick—because healthy cats are happy cats!
Felisyl L-Lysine Gel is a premium, vet-formulated daily supplement delivering 1000mg of L-Lysine in a tasty salmon-flavored gel. Designed to support immune function, ease respiratory symptoms, and promote eye health in cats and kittens, it’s NASC-certified and made in the USA for guaranteed quality. Perfect for picky eaters and effective against FHV-1 flare-ups, this gel helps your cat breathe easier, see clearer, and stay stress-resilient all year long.
























| ASIN | B00MO9SHBE |
| Active Ingredients | L-Lysine Monohydrochloride |
| Allergen Information | Codfish Free |
| Best Sellers Rank | #2,110 in Pet Supplies ( See Top 100 in Pet Supplies ) #13 in Cat Supplements & Vitamins |
| Brand | Felisyl |
| Brand Name | Felisyl |
| Customer Reviews | 4.4 out of 5 stars 1,979 Reviews |
| Flavor | Gel (5 oz.) |
| Global Trade Identification Number | 00814087006547 |
| Included Components | 1 |
| Item Form | Gel |
| Item Type Name | Felisyl L-Lysine Gel for Cats - Immune System Support - Supplement Support for Healthy Tissue, Respiratory, and Vision - Salmon-Flavored - Made in the USA - 5 oz |
| Item Volume | 5 Fluid Ounces |
| Manufacturer | Pet Health Solutions / HealthyPets, Inc. / Sogeval |
| Product Benefits | Aids Respiratory & Eye Health - Helps reduce the frequency and severity of respiratory discomfort, sneezing, runny nose, and watery eyes associated with environmental stressors., Eases Upper Respiratory Symptoms - Promotes normal respiratory tract function, making it ideal for cats prone to congestion, nasal discharge, or seasonal flare-ups., Helps Manage Stress-Related Flares - Supports a healthy immune response during stressful events like boarding, vet visits, moving, or changes in routine., High-Palatability Salmon Flavor - Smooth and tasty gel makes daily dosing easy—great for picky eaters who dislike powders or chews., Ideal for Kittens & Adult Cats - Safe and gentle enough for kittens while providing effective daily support for adult and senior cats., Supports Strong Immune Function - Delivers a daily dose of L-Lysine, an essential amino acid that helps maintain normal immune defenses and keep cats healthier year-round. Product Benefits Aids Respiratory & Eye Health - Helps reduce the frequency and severity of respiratory discomfort, sneezing, runny nose, and watery eyes associated with environmental stressors., Eases Upper Respiratory Symptoms - Promotes normal respiratory tract function, making it ideal for cats prone to congestion, nasal discharge, or seasonal flare-ups., Helps Manage Stress-Related Flares - Supports a healthy immune response during stressful events like boarding, vet visits, moving, or changes in routine., High-Palatability Salmon Flavor - Smooth and tasty gel makes daily dosing easy—great for picky eaters who dislike powders or chews., Ideal for Kittens & Adult Cats - Safe and gentle enough for kittens while providing effective daily support for adult and senior cats., Supports Strong Immune Function - Delivers a daily dose of L-Lysine, an essential amino acid that helps maintain normal immune defenses and keep cats healthier year-round. See more |
| Target Species | Cat |
| UPC | 814087006547 |
| Unit Count | 1 Count |
| Vitamins And Minerals | 1000 Milligrams |
| Volume | 5 Fluid Ounces |
| Warranty Description | 1 Month |
K**E
So Far So Good. Kitty Approved!
So far, I am pleased with this Lysine gel for my Ragdoll Kitty. I got it because my kitty was suffering from red, irritated eyes with an occasional sniffle / sneeze. I decided to try and treat this internally rather than dealing with eye drops for this problem in her eyes since it would cause her stress and it is topical so the problem would probably continue without keeping that daily regimen up. I needed something systemic and more favorable to my kitty and she is treats and food driven. I was concerned a bit with some of the reviews dealing with quality control and I am happy to say that all is perfect. It smells great, and my cat loves it. She goes for it with the gusto of eating a Churu. She has only had several doses, but I can already see improvement in the redness in the whites of her eyes. I am so happy. Happy cat, happy life. I started on the minimum dose of 1/8th tsp twice a day and I wait to give it to her on a full stomach to avoid some of the digestive upset that can occur as a side effect. The amount you get in the tube is very affordable compared to others in oral drops or other powders and gels that are super expensive on dosing average. I also felt confident to purchase Felisyl due to it receiving the seal of approval from the NASC and believe it or not, during my research of Lysine products, it is even recognized under Good RX for its health benefits and prevention maintenance for my beloved feline along with several other vet formulated lysine products, but they were double to triple the purchase price. Very happy with my decision and hoping she continues to improve in her health, allergies and keeping her immune system well and strong. This product is so much cheaper than a Vet bill or repeat visits because the symptoms are only treated instead of trying to clear the underlying condition that this gel or more like a paste actually does for her internally and systemically. Allergies begone.
M**E
Highly recommend
I've been using Felisyl L-Lysine Gel for my cat, who has lifelong allergies, and it’s been a game changer! The gel is easy to administer, and my cat doesn’t seem to mind the taste at all. Since starting the supplement, I've noticed a significant reduction in her allergy symptoms—her sneezing has decreased, and she seems much more comfortable overall. It’s reassuring to know that L-Lysine can support her immune system and help manage her allergies. This product has made a noticeable difference in her quality of life, and I highly recommend it for any cat struggling with allergies!
J**R
Helped a lot, cat LOVES it.
Cat has runny eye and can get sneezy. Vet tx'd for sinus infection but that one eye never stopped weeping. Asked if Lysine would help, he said give it a shot. We did on many types and brands but our cat loves this one best. would eat the tube if you let him. Don't do that - the diarrhea is amazing - don't ask me how we found that out. We give a little in the am and pm and when he hears the box with the tube come out he comes running. If you are consistent in giving it, it works 95% - only occasional tiny weeping, no sneezing.
M**N
Great In A First-Timer’s Pinch!
This stuff seems great! In just three days, a kitten who had one leaky eye closed, and another who was the worst off with crusted-over closed eyes and mucus oozing out the eyes and nose, were able to eat, drink, explore and groom themselves again! That first one looks, and acts, normal but I’m still administering the medicine to them and they love the taste. The second is making great recovery towards eating dry kibble on their own, and drinking water, but makes a fuss over ingesting the medicine, so I have to scoop some onto my finger, gently coax their mouth open while holding them in place by the scruff, and line their tongue with it. This one also turns away from eating canned food, now, which were never a problem before the upper respiratory issues occurred. The positives about this supplement are it seems to have a fantastically—almost—irresistible flavor cats and kittens love; it’s easy to squeeze out; finger-feeding isn’t difficult, just tedious. This product is quite creamy, with a teeny-tiny bit of stiffness similar to something like mayo; it’s not runny, until reaching its last few remnants that more so “sneeze” out of the tube rather than glide on like normal.🤣 The negatives lie within the instructions—in the sense that you’re supposed to give a certain amount, twice, daily for three to four weeks…with only five ounces of product!🤣 I bought this four days ago and practically ran into fumes by morning of that fourth day!🤣🤣 Of course, I’ve also been handing out dosages to about five outdoor-only cats (with those in the roughest shapes, who won’t lick the product off the spoon, temporarily brought indoors for the finger-feeding)! Even for someone not giving this supplement to multiple kitties who started getting the sniffles, sneezies, and the watery eye goop that kept them shut, this stuff still wouldn’t last the expected three to four weeks! Counting the dosages given daily, there have only been about 16 total, in that tube. If a single cat were receiving the recommended two servings a day, I guesstimate that would only last a little over two weeks—defffffinitely not reaching the three, let alone four, week expectation…which is a brilliant marketing strategy haha. And it worked, because I just ordered a second tube—but I am also exploring other options, and will likely leave the gel usage for those who refuse to lick it off a spoon, or any dab to their nose, and must be finger-fed. I’ve also been using it in conjunction with a high calorie supplement for those with the lowest energy, and had the scraggliest looks. Both supplements, together, are doing well! Overall, this product was perfect for my “Oh no! I need L-Lysine, fast!” situation, and has been showing results! They certainly haven’t been instant, but observing that kitten who was the absolute worst off, out of the rest of the stray colony, gradually perk up in the beginning stages of returning to normal gives a little relief that something MUST be working. They can open both eyes about halfway, now! My only gripe is, I wish this tube were at least triple its size—for the same price!🤣
K**K
Easy use
I can’t say enough good things about Felisyl L-Lysine! My 27-lb Maine Coon came down with a cold, and I started giving this to him twice a day. Within one week, he was completely back to himself — clear eyes, better energy, and no more sniffles. It was easy to give, and he tolerated it well, which is a huge win with a big, picky boy like mine. I’m so relieved to have found something that truly helped him recover so quickly. Highly recommend for any cat parent looking for extra immune support!
L**D
Helpful with Feline Herpes Virus Symptoms
My senior rescue cat has feline herpes virus and is on medication for that. Constand snotty sneezs. This seems to help compared to other food additives. This and the antiviral medication are helpful. He loves the taste so when his nose is stuffed, snotty and he can't smell his food well this seems to get him eating more. I don't put it on his food, just the recommended amount daily on a plate more as a treat. Does seem to have helped his consition some.
G**O
Only 1 out of 3 cats liked the smell and taste of this product!
Only 1 of my cats would actually eat this stuff! The other 2 cats weren't trying to go near it. I even mixed it with their food and they refused to eat their food afterwards! The one cat that loved the taste isn't even the cat that I needed this for! lol One of my furrbabies had some eye drainage and some nasal drainage which is why i was hoping it would help since she already had a steroid shot and antibiotics. I have no clue if this stuff works, I just know 2 out of 3 cats hated the smell/taste.
M**A
It's a Miracle!
I was really skeptical about this but I read the reviews and decided to give it a try. My cat, Grayson, has developed allergies and we cannot figure out why or to what. One vet said to use a Lysine powder and sprinkle it on his food. I did that everyday for about a year and it didn't do squat. I found a puree treat-like product that worked the first time but they changed the formula and it doesn't work and he won't touch it anymore. So, that was a big disappointment. I tried a bunch of other drops, treats and other things that didn't help either. I tried a saline mister. I would shut us in the bathroom with the hot water running, so the bathroom would steam up and give him a little bit of relief. I gave him a bath. That didn't help. My poor guy was suffering, coughing, and sneezing up thick snot. He sounded like Chewbacca when he was sleeping. We went to a cat only vet and she couldn't figure it out either. It wasn't a repiratory infection because we tried anitbiotics and it didn't give him any relief. We tried to figure out what he was allergic to but we couldn't figure it out...not food...not wool rugs...not litter...not plants...not dust...etc...we were at a loss. When I found this, I was really hesitant to buy it but this was my last ditch effort. I read the reviews and reread the reviews and thought what did I have to lose. This is what I found: He doesn't like the taste. I was hoping he would but no luck. I couldn't hide it in a treat or food. I put it on his paw and he walked around for 20 minutes pretending it wasn't there before he gave in and licked it off. I read one review that said she put it on her cats mouth/nose area while it was sleeping and then it had to lick it off. That sounded like a good idea. I have found that trick or putting it on his paw when he is sleeping works too. It took Grayson a full week and then suddenly he cleared up. I couldn't believe it! I was shocked and so happy. He's snoozing next to me right now and I can't hear him. I can't hear him approaching from the next room anymore. He's my fuzzy little ninja now! He's running around, seems to have more energy and seems happier. I don't notice any type of a strong smell. It's supposed to suppport his immune system and since he cleared up, I think it has helped his health. It's definitely helped my mental health because I'm not worrying about him all the time. I just pray that they don't change the formula because I would like to keep him on this long term. I do want to mention, that I gave it to him once a day for a week. Once he cleared up, I didn't give it to him for a couple of days, he was definitely sneezing and getting stuffy again. I put him back on until he cleared up...maybe 3-4 days and stopped again. He's been clear for about 4 days now. I'll give it to him as needed, when he starts to get stuffy again. I like that it doesn't have to be everyday forever. I'm keeping my fingers crossed that this is my long term solution.
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2 weeks ago
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