The Best L-Lysine for Cats (2022 Reviews)

Skylar Dial
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Cats are incredibly susceptible to herpesvirus and panleukopenia, two herpesviruses that can lead to severe symptoms, fatalities, and vomiting, particularly in kittens. Luckily, there are some good options available to protect them from these viruses.

There are many good options on the market for protecting your cat from herpesviruses, but one of the most popular and effective is L-Lysine.

And no, you can’t cook your cat!

Follow along below and learn why L-Lysine is one of the best lysine for cats, how to use L-Lysine for cats, how much to give your cat, and more!

Today, we’ll discuss:

  • What is L-Lysine?
  • What are the benefits of L-Lysine?
  • How to Give L-Lysine Properly to My Cat?
NameCategoryProduct
NOW Pet HealthBest OverallNOW Pet Health
Duralactin Feline L-LysineBudget PickDuralactin Feline L-Lysine
Vetoquinol Enisyl-F Oral Paste: L-Lysine SupplementUpgrade PickVetoquinol Enisyl-F Oral Paste: L-Lysine Supplement

1. NOW Pet Health

Our rating: 9 / 10

NOW Pet Health

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Pros:

  • Contains pure L-lysine for cats
  • Product of the USA
  • Flavors are chicken, beef, and salmon
  • Well-known supplement producer
  • Food-grade supplement
  • Low calcium ash content
  • Produced in GMP-compliant facilities
  • Created with organic and natural ingredients
  • Available at a discount

Cons:

  • Food-grade supplements require monitoring of use
  • Can cause a temporary nasal discharge

This 8-ounce container of NOW L-Lysine Powder for Cats is certified by the National Animal Supplement Council.

It comes in three flavors for your cat – chicken, beef and salmon. A package contains 60 doses which can last about 30 days.

The recommended dosage for this supplement is 10-60mg per day. Each scoop of beef contains 555mg of pure l-lysine powder.

2. VetriScience Laboratories Vetri Lysine Plus

Our rating: 8 / 10

VetriScience Laboratories Vetri Lysine Plus

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Pros:

  • Ingredients are 100% animal-sourced “ no plant-based ingredients
  • Contains high quality vitamins and amino acids
  • Discounted, if you buy 6 chews or more
  • Comes with a 100-day money back guarantee
  • Very affordable
  • Easy to administer
  • Also contains some wonderful herbal ingredients like Echinacea, Goldenrod, and Green Tea
  • Excellent reviews on Amazon

Cons:

  • Seems to be a bit hard to find
  • Not sold at retail stores
  • Some believe it may contain fillers

3. L-Lysine Soft Chews Optix Care Nutritional Supplement

Our rating: 8 / 10

L-Lysine Soft Chews Optix Care Nutritional Supplement

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Pros:

  • (5 / 5)
  • Great product
  • Extra large doses
  • Good price for the quality
  • Thicker than most other chewables
  • Promotes health in stressful times

Cons:

  • (3 / 5)
  • Large size
  • Odor
  • Bit too big

Formulated to promote & support the immune system during times of stress.

If you’re searching for the best l-lysine for cats, then you can’t go wrong with these L-Lysine Soft Chews from Optix Care. They’re specially formulated to provide large doses of l-lysine to your cats during times of stress. Which is exactly what you need during stressful times.

Plus, since they’re chewable, your pets won’t resist taking them.

4. L-Lysine Supplement

Our rating: 8 / 10

L-Lysine Supplement

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Pros:

  • 100% vegan formula
  • Comes with a 100% money-back guarantee
  • Safe for long-term use
  • Made in the USA with the highest quality ingredients
  • Reasonable price
  • Safe for pregnant and nursing cats

100% Vegan – 1 gram of L-Lysine for Every 2.1 lb of Cat or Kitten Weight

Having an indoor cat is a blessing, but it’s important to know that cats are naturally drawn to insects and other animals they can catch and hunt. This is what helps them to develop their natural hunting instincts which keeps them occupied.

That’s one of the reasons why so many cat guardians worry about their indoor cats. Their cats get bags of attention inside, but they get little attention beyond the home.

5. Lysine for Cats

Our rating: 8 / 10

Lysine for Cats

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Pros:

  • My top L-Lysine for cats recommendation makes use of Llysine Kitten, a cold and upper respiratory infection treatment spray.
  • And the two reasons for this are as follows.
  • The first is that it really does work at warding off colds and upper respiratory infections.
  • And the second is that it's inexpensive, easy to administer, and highly well-tolerated by most cats.
  • Lysine is one of the amino acids our bodies use to make proteins.
  • And it's not just any old protein – it's essential to the production of proteins called antibodies.
  • These antibodies help ward off viruses that can affect the respiratory system, including feline herpes.
  • But unlike the virus and the feline herpes, Llysine is easily absorbed into cats' systems.
  • In fact, it can be administered orally, topically or as a suppository.
  • And it's almost completely risk free.

6. Thomas Pet Felo Lysine

Our rating: 8 / 10

Thomas Pet Felo Lysine

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L-lysine for cats is going to be the answer you’ve been looking for if your pet is suffering from feline herpes virus (FHV), a stubborn condition that plagues many Birmans. This is recommended to use in conjunction with a vet-approved program.

In cats, the symptoms of feline herpes include:

If your Birmans ears are constantly flaring up – then this probably has something to do with their herpes.

7. Felisyl Immune System Support

Our rating: 8 / 10

Felisyl Immune System Support

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Our Review:9,8kg gives your cats the antioxidants and L-lysine they need to stay healthy

Proprietary Immuno support complex of Zinc, L-lysine and Vitamin C plus MSM.

Supports maintaining healthy tissue, respiratory health, vision and healthy immune response.

8. Vetoquinol Enisyl-F Lysine Bites: L-Lysine Chews

Our rating: 7 / 10

Vetoquinol Enisyl-F Lysine Bites: L-Lysine Chews

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Pros:

  • Made with real chicken liver
  • Used to treat cat herpes often caused by a viral infection
  • May lead to healthy skin and coat
  • A good addition to any cat food
  • For use on cats and kittens 8 weeks or older

L-lysine is an amino acid the body requires to produce the protein used to build cells.

This product is a chewy tablet, made with real chicken liver. This is one of the newest formulations for the prevention of respiratory tract signs caused by Feline Herpes Virus-1, cats often develop ear, nasal, and eye infections with herpes. L-Lysine is recommended by veterinarians to treat this herpes, but is a prescription only from your vet.

L-Lysine is an essential amino acid found in animal meat, so it required by cats. This supplement helps maintain and promote a healthy immune system in cats. It acts as a supplement to your cat’s diet, and they should be used for up to 2 weeks twice a day for best results. It’s an easy way to protect your cat from a variety of illnesses.

9. Pet Naturals of Vermont Lysine FunShaped Chews

Our rating: 7 / 10

Pet Naturals of Vermont Lysine FunShaped Chews

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Pros:

  • Highly palatable chewable tablet that doesn’t need to be hidden in food
  • Made with ingredients sourced from the USA
  • Made with high quality, all-natural ingredients
  • Safe for daily use; made to ensure your cat gets the required daily dose of lysine
  • Regular use can limit the amount of time kitty spends licking and biting
  • Bonus: Each purchase supports a no-kill animal shelter program
  • Bonus: Each purchase includes a free second bottle
  • Bonus: Each purchase comes with a 100% money-back guarantee
  • Bonus: Their customer service is available 24/7 to help you out
  • Convenient way to make sure your cat gets the daily dose of L-Lysine; highly palatable and made with high-quality ingredients

Cons:

  • You’ll have to hide it in food as it doesn’t have a pleasant taste
  • The price is a bit higher than other brands on the market
  • Takes some time for it to take effect

10. Global Pet Nutrition L-Lysine Powder

Our rating: 7 / 10

Global Pet Nutrition L-Lysine Powder

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Pros:

  • Protects against a variety of cat viruses
  • Easy to administer
  • Tastes great
  • Huge product container
  • Relatively cheap
  • Effective
  • Great quality

Calici Virus, Coronavirus, And Feline Viral Rhinotracheitis Virus.

11. L Lysine

Our rating: 7 / 10

L Lysine

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Pros:

  • 90ct of L-Lysine supports your cat’s immune system
  • FDA-approved
  • Made in the USA
  • Comes in a delicious chicken flavor
  • 90ct of L-lysine can be used for a 90 day period
  • 3.74oz
  • 30-day money back guarantee
  • Half of the recommended amount, twice a day
  • Slow release formula

Cons:

  • Expensive (compared to some other L-Lysine supplements)
  • Pediatrician recommendations for optimum immune system health: 2 million IU per day

12. Duralactin Feline L-Lysine

Our rating: 7 / 10

Duralactin Feline L-Lysine

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13. Nutrition Strength Lysine

Our rating: 7 / 10

Nutrition Strength Lysine

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This cat supplement features an exciting natural formulation that’s loaded with fresh and nutritious ingredients your cat will love.

This supplement is 100% vegetarian friendly has no preservatives or artificial colors. Shpure’s Nutrition Strength Lysine for Cats is the highest potency L-Lysine on the market. This vegetarian formula is storable and delivers maximum benefit.

14. Tomlyn Immune Support Daily L-Lysine Supplement

Our rating: 7 / 10

Tomlyn Immune Support Daily L-Lysine Supplement

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Lysine is an essential amino acid needed for tissue development, proper growth, and collagen production in cats.

Amino acids act as precursors for muscle and joint tissue. Lysine helps the body make other amino acids, specifically arginine and glutamine, which are also building blocks for collagen.

Lysine also assists with muscle movement and therefore is a necessary part of any diet, supplementing inflammatory issues and joint pain in cats.

15. BEST PET SUPPLIES LLC Allergy Immune Bites

Our rating: 7 / 10

BEST PET SUPPLIES LLC Allergy Immune Bites

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Pros:

  • Strong natural immune booster
  • Effects that last a really long time
  • Small, easy to use doses
  • Great product for those who are on a tight budget

The Allergist's Guide owners Stanley Rosenberg and Kelly Mallon have created a formula made from lysine that reduces the most common allergic response cats and dogs experience, including irritation from seasonal allergies and itching from fleas.

The formula is easily digestible, soluble in both water and alcohol, and has been extensively tested over many years.

The recommended dosage is 1/64th of a teaspoon, added to your pet’s food. This formula helps to optimize your pet’s immune system to allow it to naturally fight vaccination reactions, allergies, and the seasonal joys that come with springtime and warmer weather. The formula is also formulated for cats and dogs who need to be protected from intestinal worms and other parasites.

16. Vetoquinol Viralys L-Lysine Supplement

Our rating: 7 / 10

Vetoquinol Viralys L-Lysine Supplement

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(8 oz)

We recommend Vetoquinol Viralys l-lysine supplement because of its effectiveness and high-quality ingredients.

This product uses a balanced amino acid, l-lysine, which helps kitty to build a healthy immune system. At the same time, it helps kitty to battle any number of existing illnesses.

17. Vet Worthy Lysine Paw Gel Aid

Our rating: 7 / 10

Vet Worthy Lysine Paw Gel Aid

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Pros:

  • Good price
  • Tougher formula than the powder version
  • Vet recommended
  • The gel makes it easier to administer
  • Ease of application
  • Does not have an unpleasant taste
  • May have a long shelf life
  • Easy to administer
  • Good for those who have a hard time giving pills to their cats

Cons:

  • No scientific backing for it being faster than the powder form
  • The gel takes a long time to dry
  • The tube is hard to squeeze out
  • Not easily available
  • Capsules are awkward to open

If you are looking to purchase a Lysine supplement for your cat, this Vet Worthy brand one is among the best you can find. The 3 oz. tube is a great way to buy Lysine for cats, particularly if you have a hard time getting them to take their pills or giving them a liquid form. This is because it’s gelled and thus has a better shelf life than other forms of Lysine for cats, which could be a strain on your finances.

18. L-Lysine 500mg

Our rating: 7 / 10

L-Lysine 500mg

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L-Lysine for cats is the ideal supplements for cats with herpes, cold sores, FIP virus, URI, Feline Herpesvirus 1 & Calici-Virus. According to the manufacturer it may also help your cat if they have Feline Immunodeficiency Virus (FIV), Feline Infectious Peritonitis (FIP), eye infections such as conjunctivitis. It may also help them fight an upper respiratory tract infection also known as URI.

The dosage is between 400mg to 500mg daily for the first two weeks, then it’s recommended to give 250mg daily until the condition is resolved.

When giving this to your cat it’s best to either mix it in with their food or give it to them with a syringe. One of the best things about L-Lysine is that it’s a natural and safe substance which comes from a plant. And the best part is that it can be given to cats even when they’re pregnant.

19. MY LUCKY PETS LLC cat Eye Care

Our rating: 7 / 10

MY LUCKY PETS LLC cat Eye Care

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Pros:

  • Great dose for cats
  • Balanced with amino acids
  • Multi-purpose, used to boost your cat’s immune system and also for skin care
  • My lucky pets is a trusted brand
  • 100% manufacturer’s warranty (Peace of mind)

What is L-lysine and why is it good for my cat?

L-lysine is an essential amino acid. It’s important to our body and is one of the first to diminish in times of stress such as colds or allergies. L-lysine is found in high protein sources like meat or poultry. It’s likely that your cat isn’t ingesting enough L-lysine in their daily diet.

The use of L-lysine in cats can:

20. Vetoquinol Viralys Gel L-Lysine Supplement

Our rating: 6 / 10

Vetoquinol Viralys Gel L-Lysine Supplement

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L-lysine is an essential amino acid that helps promote strong immune system functions in cats. This supplement also contains vitamin C which helps boost immunity in a natural way.

This lysine gel is made for cats of all ages and is a lifesaver for cats that suffer from sneezing, runny nose, squinting, and watery eyes.

21. Tomlyn Immune Support Daily L-Lysine Supplement

Our rating: 6 / 10

Tomlyn Immune Support Daily L-Lysine Supplement

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We recommend the L-Lysine supplement from Tomlyn, taking into consideration several factors like customer service and value for money. Although the packaging might be designed for cats, it’s very easy to open and close for people.

Overall this L-Lysine supplement from Tomlyn is a great way to add an immune booster to your cat’s diet.

The supplement is made from pure l-lysine hydrochloride, adding an essential amino acid to your cat’s diet. Lysine requirements are increased for cats who are stressed, pregnant, nursing, or over 6 years of age.

22. MPP Cat Healthy Supplement Immune Eye Respiratory or Hairball Aid Pumpkin Soft Chews

Our rating: 6 / 10

MPP Cat Healthy Supplement Immune Eye Respiratory or Hairball Aid Pumpkin Soft Chews

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The MPP Cat Healthy Supplement Immune Eye Respiratory or Hairball Aid Pumpkin Soft Chews contains pumpkin which has several benefits for cats such as acting as a natural laxative. It also works as a demulcent to protect the stomach lining and to help cats who have problems with dry or watery eyes.

The supplement aids in digestion especially for cats with delicate stomachs. It helps them to keep a healthy coat. It’s good for cats who are experiencing a change in seasons. The supplement is recommended for overall health and well-being. The nutritional supplement is natural and safe and contains no artificial flavors or colors.

The formula is palatable and cats will enjoy the small soft chews. It’s also easy to store and is suitable for cats of all ages.

23. DRS. Foster and Smith L-Lysine Soft Chews

Our rating: 6 / 10

DRS. Foster and Smith L-Lysine Soft Chews

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If your cat is suffering from cold sores, then try the L-Lysine Soft Chews for Cats by DRS. Foster and Smith and see how it works. Not only will this help heal the cold sores, but it will also help prevent future outbreaks.

It contains L-Lysine, which is an essential amino acid that helps to support healing and reduce the frequency of herpes virus outbreaks.

This supplement comes in a great-tasting soft chew that you can simply give to your cat, and they’ll gobble it up.

24. Vetoquinol Enisyl-F Oral Paste: L-Lysine Supplement

Our rating: 6 / 10

Vetoquinol Enisyl-F Oral Paste: L-Lysine Supplement

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Pros:

  • Details the benefits of this product
  • Reviews that state this is a great product
  • Considerable amount of good reviews
  • Has a decent amount of positive reviews
  • Good quality and price
  • Has a fair price
  • Great viscosity

25. Buddy & Lola L Lysine

Our rating: 5 / 10

Buddy & Lola L Lysine

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If you’ve been looking for the best L-Lysine for cats, you’ve probably read plenty of reviews online, and you’ve probably noticed that the other products on our list aren’t the cheapest. While Buddy & Lola doesn’t break the bank, it’s just as good as the more expensive supplement options out there.

It has some awesome benefits for your feline friend. The formula is packed with essential vitamins and nutrients that will help with infections, upper respiratory problems, and other allergy-related issues. The supplement is also amazing for keeping your cat’s coat shiny and healthy.

Another perk about the Buddy & Lola supplement is that it comes in an easy-to-use capsule form. All you have to do is give it to your cat with some food. And, unlike other diet supplements where the taste is overwhelming, the taste of this product is extremely approachable.

Frequently Asked Questions (FAQ)

What is the best lysine supplement for cats?

Always look for l-lysine or lysine hydrochloride.  L-lysine is the natural form and is more effective. Most cats tolerate L-lysine better, but there are some that are reactive to it and can get digestive upset or loose droppings. These are typically the sensitive cats and are usually overweight.

How much L Lysine should I give my cat?

L-Lysine is an essential amino acid which has proven to be extremely effective against herpes virus infections in cats. The dosage that is required to achieve beneficial results is between 50mg and 150mg of L-lysine to each cat per day, divided in three or four servings.

The dosage is based on a cat weighing about 8 pounds and you can consult your vet in order to know the appropriate dosage for your cat.

Does lysine really work for cats?

Lysine treats cold sores in humans, but the jury is still out on whether it helps cats with Feline Herpes. Cats with these symptoms will need prescription medication. A good rule of thumb is that if you are the slightest bit concerned about your pet, you should go see a vet.

L-Lysine is also helpful for cats if they ingest the L-Lysine chicken treats.

Cats should not take L-Lysine as a daily vitamin. Lysine is an amino acid which breaks down into proteins and cannot be stored by the cat. Over time, excessive amounts of L-Lysine can lead to body tissues breaking down.

Does lysine help cats with colds?

L-lysine for cats is a commonly used supplement to help cats cure themselves from colds. While it's not an approved, scientific cure, it may speed along the healing process.

Many of the things that make cats susceptible to cold viruses also will make their bodies slow down their own ability to fight off the infection, such as stress and compromised immune systems. L-lysine may help cats recover faster because it can help the immune system become more efficient.

The body does not have a ready supply of lysine, so it must be replenished daily. The amount that is considered safe and helpful varies by pet, type of food, and dosage.

Conclusion

Lysine is one of the most common supplements prescribed by veterinarians to prevent and treat feline herpesvirus infection, commonly referred to as FHV, which is the feline version of the common cold.

Feline herpes is found among cats of all ages and breeds. Young cats between 1 and 3 years are thought to have an increased risk for contracting the virus; however, cats of any age can be infected.

Our Recommendation

NameCategoryProduct
NOW Pet HealthBest OverallNOW Pet Health
Duralactin Feline L-LysineBudget PickDuralactin Feline L-Lysine
Vetoquinol Enisyl-F Oral Paste: L-Lysine SupplementUpgrade PickVetoquinol Enisyl-F Oral Paste: L-Lysine Supplement