Gabapentin can increase appetite in cats, though it’s not the most common side effect. The more typical reactions are sedation and mild coordination problems. Still, if your cat seems hungrier than usual after starting gabapentin, the medication is a likely explanation.
What the Evidence Shows
Research comparing gabapentin to other medications in cats after surgery found that gabapentin led to greater food intake within the first two hours after waking up. A comparative study also found that both gabapentin and mirtazapine (a drug specifically prescribed to boost appetite) increased appetite and improved demeanor in cats, though gabapentin had a stronger sedative effect alongside it.
This means gabapentin has a real, measurable effect on hunger in cats. It’s not just anecdotal. However, it’s worth noting that increased appetite isn’t listed among the most frequently reported side effects in veterinary reviews. The effects vets see most often are ataxia (wobbly, uncoordinated movement), sedation, hypersalivation, and occasionally vomiting. In one study, 9 out of the cats observed had hypersalivation, 3 had ataxia, and 1 had vomiting. Increased appetite doesn’t show up in those adverse-event counts because, frankly, most cat owners and vets consider it a welcome side effect rather than a problem.
Why Gabapentin Affects Appetite
Gabapentin was originally developed as a pain and anxiety medication. It works by calming overactive nerve signaling, which is why its dominant effects in cats are sedation and reduced stress. Cats given gabapentin before vet visits, for instance, consistently show less fear and anxiety compared to those given a placebo.
The appetite connection likely comes from that same anxiety-reducing effect. Stressed or painful cats often eat less. When gabapentin dials down pain signals and lowers anxiety, a cat that was too uncomfortable or nervous to eat may suddenly show interest in food again. In post-surgical cats, this effect is especially noticeable because pain and the lingering effects of anesthesia suppress appetite. Gabapentin appears to clear that barrier faster than some alternatives.
There may also be a more direct effect on hunger signaling, similar to what’s observed in humans taking gabapentin for nerve pain. Weight gain is a recognized side effect in people on long-term gabapentin, and while cats metabolize drugs differently, the underlying mechanism of calming certain nerve pathways could influence appetite centers in a similar way.
Sedation and Appetite Often Come Together
If your cat is both sleepier and hungrier on gabapentin, that’s a common combination. The sedative effect is the most consistent and well-documented response in cats. Studies using doses around 20 to 22 mg/kg found significant increases in sedation in both young and geriatric cats. Interestingly, researchers found no clear relationship between the exact dose and the severity of side effects. Some cats are simply more sensitive to gabapentin than others, regardless of how much they receive per kilogram of body weight.
Geriatric cats tend to be more affected overall. Their bodies process the drug more slowly, so both the sedation and any appetite changes may be more pronounced or last longer. If your older cat seems dramatically hungrier or groggier, that’s consistent with what veterinary research has found.
When Increased Appetite Is the Goal
For cats who have stopped eating due to chronic illness, pain, or post-surgical recovery, gabapentin’s appetite-boosting effect can actually be useful. Vets sometimes prescribe mirtazapine as a dedicated appetite stimulant, but gabapentin offers a two-for-one benefit in cats that also need pain or anxiety management. The research comparing the two drugs found both were effective at getting cats to eat more, making gabapentin a practical choice when appetite loss accompanies a pain condition.
Cats with osteoarthritis, nerve pain, or chronic stress-related conditions are common candidates for long-term gabapentin use. If your cat falls into this category and has been eating poorly, a bump in appetite after starting gabapentin is a positive sign that the medication is reducing whatever discomfort was suppressing their interest in food.
Managing Your Cat’s Weight on Gabapentin
If your cat is on gabapentin long-term and gaining weight, the combination of increased appetite and reduced activity from sedation can work against them. A cat that’s eating more but moving less will put on weight, and excess weight worsens joint pain, creating a frustrating cycle for cats already being treated for arthritis or mobility issues.
Portion control is the most straightforward approach. Rather than free-feeding, measure out your cat’s daily food and divide it into scheduled meals. This lets you track exactly how much they’re consuming and adjust if the scale starts creeping up. If your cat is begging for food between meals, puzzle feeders or small, frequent portions can help stretch the same amount of food across the day.
It’s also worth paying attention to the timeline. Many cats experience the strongest side effects, including appetite changes, in the first week or two of starting gabapentin. As their body adjusts, the hunger boost may level off while the pain-relieving benefits remain. If the increased appetite persists and weight gain becomes a concern, your vet can explore adjusting the dose or switching to an alternative.