Best Cat Antioxidant Supplements of 2026

"When my beloved 19-year-old cat was diagnosed with multiple health issues, including cancer, I turned to this product as a last hope. Within days, she went from nearly lifeless to sitting up, eating, and even moving around the house again. It truly gave her a quality boost in her final days. I sincerely wish I had discovered this sooner and highly recommend it for any cat facing a tough diagnosis."

"My 16-year-old cat started to slow down and lost interest in food, despite being wormed. After trying this supplement, he became more satisfied at mealtimes, started enjoying the sunshine again, and his coat improved noticeably. I'm honestly surprised by the difference and plan to keep him on it. Definitely recommend for aging cats."

"I tried this product for my cat undergoing chemo for kidney lymphoma. Unfortunately, he became weaker and lost his appetite after starting it. Once I stopped the supplement, he perked up and regained some strength. It seems this product doesn't suit every cat, so monitor your pet closely if you try it."

"I've never seen my cats so excited for a treat before! As soon as I open the Pet Honesty Cat Probiotics Gut + Immune Health Chews, my crew goes wild. These chews have worked wonders for their digestion, coat, and energy—even hairballs are no longer an issue. I really like the clean ingredients with no junk inside. Treat time has become a highlight of the day for my cats and me."

"My cat used to hack up hairballs constantly and nothing else helped, but these treats made a noticeable difference almost immediately. No more hairball messes around the house! I now just give him a couple as a maintenance dose and he's doing great. I’ll definitely be buying these again."

"My picky cat absolutely loves these treats and his vomiting from hairballs has finally stopped after a few weeks. We tried many other remedies with no luck, but this is the first thing that really worked for him. I'm so glad to have found a solution that he enjoys every morning."

"My cat struggled with sneezing and a runny nose for a month, but after starting these, I noticed a dramatic improvement within a week. Her symptoms vanished, her eyes and coat looked great, and she actually enjoys eating these as treats. At 11 years old, seeing her so healthy and happy is a big relief for me."

"Whenever the pollen count rises, my three cats used to sneeze and get watery eyes. After giving them these chews for about nine months, I’ve seen a clear, positive difference. I’m so satisfied, I’ve set them up on auto-delivery. Plus, they actually like the flavor!"

"I have a blind kitten with chronic congestion, and these chews seem to make breathing easier for him. I also notice my other cats’ eye issues don’t last as long when they have these. They're soft enough to break up for kittens, but if I leave the bag open, the chews become hard quickly."

"After just a few days, I noticed a significant improvement in my cat's respiratory symptoms. Her sneezing stopped, her eyes cleared up, and she actually looks forward to getting these chews as a treat. The texture is a bit firm, but she doesn't seem to mind at all—she loves them!"

"I’ve tried other NaturVet products, but these chews were unusually hard. My cat couldn't chew them at all, and even I had trouble breaking them up, so unfortunately, they just didn’t work for us."

"Giving my cat his medicine has never been easier—these treats make it simple and stress-free. He eats them without fuss, and his eye issues cleared up quickly. I highly recommend them for anyone with a fussy cat!"

"I usually never write reviews, but I had to for this because it worked amazingly well for my four indoor cats suffering from a cold and allergies. Even my feline herpes-positive rescue had no more symptoms after using it! My cats actually eat these up, and their energy and grooming returned quickly. Just make sure to follow the dosing instructions based on their weight—this stuff made a huge difference for us!"

"I started using this supplement for my 18-year-old cat to boost her immune system, and I’m impressed. She’s had fewer sneezing episodes and seems more comfortable overall. The fact that she actually likes the flavor makes it so much easier to give, and I appreciate the lysine, colostrum, and omega-3s in the formula. I’ll definitely keep buying it."

"After trying these treats, I’ve noticed a big reduction in my cats’ sneezing. Both my cat and kitten enjoy them, and I’m really happy to see results so quickly. I would absolutely recommend to anyone with similar issues—10/10 satisfaction!"

"I've used this product for years and it's saved the lives of several of my cats. I absolutely recommend it for anyone with companion animals."

"My cat was suffering from severe stomatitis and needed lifelong steroid treatments. Adding this supplement has helped me space out his steroid doses, and he actually likes the taste when mixed with water. My only gripe is that the bag is a bit small for the price."

"I tried this for my two kittens with chronic sneezing. One of them threw up each time after eating it, and the other ended up with a ringworm infection. Not sure if it's related, but unfortunately, I can't recommend this product."

"I've struggled to get my two adopted kitties to eat any supplements, but this one is a total game changer. Even my picky cat with respiratory issues eats it right up! Since starting, I've seen more playfulness and energy, and even my other kitty's eye looks better. Happy cats, happy me—I definitely plan to keep using it."

"At first, I worried my Maine Coon would turn up his nose at the color and smell, but now he demands this supplement every day! We're using it with other healthy foods and he's more content and playful than ever before. Whatever we're doing, this product is a key part of his transformation."

"After some trial and error, I found that mixing this supplement with the right wet food means my cats eat it willingly. Since adding it to their diets, I've noticed shinier fur, less shedding, and more energy. I feel good about the quality, and am happy to recommend it to other cat owners."

"My cats absolutely love these treats! The treat form makes it easy for them to eat, unlike the liquid version which they never cared for. These are a big hit in my house and I’ll keep buying them."

"I noticed that after starting these chews, my cat’s sneezing and eye discharge significantly improved and she even started eating better. She usually refuses larger treats, but she devoured these right away. I’m so relieved to see her getting better—whether it’s coincidence or not, I’m happy with the results!"

"At first, two of my three cats seemed to enjoy these, but after a short while, they lost interest and stopped eating them. I’ll be returning to my previous brand, though this might work well for other cats."

"I've tried so many supplements for my cat's allergies and sneezing, but these chews are the first he actually enjoys eating. He’s very fussy, but he gobbles these up once I break them into small pieces. I’m really hoping they’ll help with his runny nose and sneezing!"

"My boy has had a persistent watery eye for months, and the vet suspects herpes. Since starting these chews, his eye symptoms have definitely calmed down, and he actually likes the taste. I just make sure to keep the bag out of reach because he’d eat them all if he could."

"One of my cats is extremely picky, but he loves these treats and they seem to help her chronic upper respiratory infections. I just wish every batch was as fresh and moist as usual, though customer service was quick to refund and replace when I got a stale pack."