L-Lysine Soft Chews For Cats Supplement
Verified Jun 11, 2026
A soft chew lysine supplement for cats, designed to support general immune function. Each chew provides 250 mg of L-lysine along with a whitefish flavor and brewers yeast base to make it more palatable. This can be useful for cats who need extra lysine support in an easy, treat-like form.
This is a well-formulated lysine supplement for cats that delivers a clear, measurable dose of L-lysine in a soft chew format many cats will accept as a treat. It’s a reasonable option when a veterinarian has recommended lysine, especially for cats where mixing powders into food is difficult. As with any supplement, it should be used alongside, not instead of, a complete and balanced diet and appropriate veterinary care.
The KibbleLab Score (1–10) is assessed from publicly available product data. Our evaluation is science-based, not marketing-based.
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At a Glance
KibbleLab Review
Strengths
- Provides a defined 250 mg of L-lysine per chew, making it easy to dose consistently based on your vet’s recommendations.
- Soft chew format with whitefish flavor can be easier to give than powders or pills, especially for picky cats.
- Free from corn and artificial flavors or dyes, which some owners prefer to avoid and which add no nutritional benefit.
- Includes modest fat and protein levels typical of a small treat, so it adds only about 5 kcal per chew, which is easy to fit into most cats’ daily calories.
Considerations
- This is a supplement, not a complete and balanced diet, so it should only be given in addition to a regular cat food that meets AAFCO standards.
- Contains fish (whitefish) and brewers yeast, which can be problematic for cats with known fish or yeast allergies or sensitivities.
- L-lysine is not universally necessary for all cats; it’s best used under veterinary guidance, especially for long-term, daily use.
Full Ingredient List
Ingredients and analysis reflect manufacturer data at the time of our last update and can change without notice. Always check the actual product packaging before feeding.
Ingredient filtering helps identify compatible options but is not a substitute for a veterinary elimination diet.
Top 5 Ingredients Explained
01
L-Lysine Monohydrochloride
L-Lysine monohydrochloride is a pure, crystalline form of the essential amino acid lysine used in dog and cat foods and supplements to ensure adequate lysine for protein synthesis, immune function, growth and tissue repair when dietary intake may be insufficient. It is generally safe at recommended levels and helpful for balancing amino acid profiles in low-protein or plant-based formulations, but should be used according to formulation guidelines because excessive supplementation can disrupt amino acid balance (notably arginine) and it is not a substitute for complete dietary protein.
02
Brewer's Yeast
Brewer's yeast (deactivated Saccharomyces cerevisiae) is commonly used in dog and cat foods as a flavor enhancer and supplemental source of protein, B‑complex vitamins, trace minerals and immunomodulating components such as beta‑glucans. It can support skin, coat and general nutritional status, but may cause gastrointestinal upset or allergic reactions in yeast‑sensitive pets, is not a live probiotic, and should be used cautiously in animals prone to purine‑related issues or those receiving antifungal medications.
03
L-Lysine Monohydrochloride
L-Lysine monohydrochloride is a pure, crystalline form of the essential amino acid lysine used in dog and cat foods and supplements to ensure adequate lysine for protein synthesis, immune function, growth and tissue repair when dietary intake may be insufficient. It is generally safe at recommended levels and helpful for balancing amino acid profiles in low-protein or plant-based formulations, but should be used according to formulation guidelines because excessive supplementation can disrupt amino acid balance (notably arginine) and it is not a substitute for complete dietary protein.
04
Vegetable Glycerin
Vegetable glycerin is a plant-derived humectant and sweet-tasting solvent commonly used in pet foods and treats to retain moisture, improve texture, dissolve flavorings or vitamins, and enhance palatability. It provides usable calories, is generally regarded as safe for dogs and cats in typical amounts, but excessive intake can cause digestive upset and may be a consideration for diabetic pets or those needing calorie-restricted diets.
05
Whitefish
Whitefish (such as pollock, cod, or haddock) is commonly used in pet foods as a lean animal protein source that provides high‑quality essential amino acids, good digestibility, and some omega‑3 fatty acids to support skin, coat and muscle maintenance. While generally palatable and useful for weight‑managed formulas, pet parents should be aware of potential fish allergies and the importance of responsible sourcing and processing to minimize contaminants; cats also require adequate dietary taurine, so whitefish should be part of a complete, balanced diet.
Nutritional Breakdown
How to read As Fed versus Dry Matter
As fed shows the numbers straight off the label, water included. Dry matter removes the water so you can compare a wet food and a dry food fairly.What is calorie density
How many calories the food packs per unit. Denser foods mean smaller portions for the same calories.Product Details & Brand
Product Specs
Brand
Under the Weather Pet is a pet food and supplement brand offering freeze-dried bland diets, broth toppers, and wellness chews for dogs and cats. The brand targets health-conscious pet owners seeking convenient, vet-formulated solutions for digestive upset and recovery support.
Visit Under the Weather PetManufacturer
All Under the Weather products are manufactured in the United States in facilities that follow FDA and USDA guidelines. The company emphasizes quality control, sourcing premium human-grade ingredients, and producing small batches to ensure safety and nutritional integrity.
Manufacturing details are compiled from public sources and not independently verified; they may not reflect contract manufacturing or co-packing.
Recall History
Under the Weather Pet L-Lysine Soft Chews For Cats Supplement has no recalls since 2014.
Source: FDA Pet Food Recall Database · Monitored daily
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Frequently Asked Questions
Has Under the Weather Pet ever been recalled?
We have no recalls on record for Under the Weather Pet. We monitor the FDA Pet Food Recall Database daily.
How does KibbleLab rate foods?
Our scores are based on ingredient composition, nutritional profile, AAFCO compliance, and health considerations. We don't penalize by-products, grains, or synthetic preservatives. Brands cannot pay for higher scores.
Is KibbleLab a substitute for veterinary advice?
No. KibbleLab provides data-driven food analysis, not medical advice. Always consult your veterinarian before making dietary changes, especially for pets with health conditions.
KibbleLab provides informational content only. This is not veterinary advice. Always consult a qualified veterinarian before changing your pet's diet.
KibbleLab may earn affiliate commissions through product links. No one can pay for a higher score, or to change what we recommend for your pet.
Product data sourced from manufacturer websites, AAFCO statements, and FDA recall database. Last verified dates reflect our most recent data check.
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