Do hairball treats actually work?

Mildly. Most hairball treats and pastes are petroleum-based lubricants (mineral oil, petroleum jelly) or fiber, both of which can help swallowed hair pass through the gut. The effectiveness is real but modest, and they don’t replace the upstream fix, which is removing the hair before the cat swallows it. Daily brushing for long-haired and senior cats does more than any treat. Use treats and pastes as a backup, especially during heavy-shed seasons, rather than as the foundation. Watch the calorie load if you’re using them daily.

When to call a vet: if your cat needs daily hairball remedies just to function, that’s a flag worth raising with your vet — prescription hairball diets or other interventions may help more.