Price: $18.99
(as of Oct 24, 2025 17:29:14 UTC – Details)
From the brand
Felisyl L-lysine Immune System Support Gel is a product designed to support the immune system of cats. L-lysine is an essential amino acid that plays a crucial role in various biological functions, including immune system function.
L-lysine is known to inhibit the replication of the feline herpesvirus, which is a common viral infection in cats that can cause respiratory and eye symptoms.
Immune System Support for Cats
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Immune System Support for Cats
Product Dimensions : 8 x 3 x 2 inches; 5 ounces
Item model number : FEL6547
Date First Available : December 15, 2013
Manufacturer : Pet Health Solutions / HealthyPets, Inc.
ASIN : B00MO9SHBE
Best Sellers Rank: #1,819 in Pet Supplies (See Top 100 in Pet Supplies) #9 in Cat Supplements & Vitamins
Customer Reviews: 4.4 4.4 out of 5 stars 1,464 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
Immune System Support – Packed with L-Lysine (an essential amino acid) to bolster your cat’s immune defenses. A stronger immune system helps keep your kitty healthier and more resistant to common feline illnesses, giving them the best chance at a long, happy life.
Respiratory & Eye Health – Formulated to support clear breathing and overall wellness in cats. Felisyl’s immune-boosting action helps ease sneezing, runny nose, and watery eyes associated with common respiratory issues, so your cat can breathe easy and stay comfortable every day.
Tasty, Easy-to-Give Gel – Highly palatable salmon-flavored gel that cats love, making supplement time feel like a treat. No more struggles with pills – simply place the gel on your cat’s paw or nose and they’ll lick it off willingly, ensuring stress-free daily dosing.
Vet-Formulated & Trusted – Developed by veterinarians for optimal feline health benefits. Felisyl is also vet-recommended, trusted by vets for its proven benefits and positive impact on cats’ lives. Pet parents can feel confident knowing this immune support gel is backed by experts and real results.
NASC Certified Quality, Made in USA – Manufactured to the highest quality and safety standards set by the National Animal Supplement Council. Felisyl carries the NASC Quality Seal and is proudly made in the USA, so you can trust you’re giving your cat a safe, premium-grade supplement for their well-being.
Customers say
Customers find the L-Lysine gel effective at boosting their cats’ immune system and helping with sneezing and runny eyes and nose, while appreciating its tasty salmon flavor and easy-to-administer gel form. The product receives mixed feedback regarding value for money, with some finding it great for the price while others consider it not worth the cost. Customers disagree on their cats’ acceptance of the product, with some reporting their cats love it while others say their cats refuse to eat it.