Yes, catnip is generally safe for cats. It's a non-toxic and non-addictive herb. Most cats respond to catnip with playful behavior, and the effects are temporary. However, not all cats are equally sensitive to catnip, and some may not react to it at all.

The effects of catnip typically last for about 10 to 15 minutes. After this period, cats often lose interest in catnip, and it may take some time before they become responsive to it again.

Catnip comes in various forms, including dried leaves, sprays, and catnip-infused toys. The best form depends on your cat's preferences. Many cats enjoy catnip-infused toys that they can bat around and pounce on. Experiment to see what your cat prefers.

Not all cats are affected by catnip. Sensitivity to catnip is hereditary, and it's estimated that about 50-70% of cats are responsive to it. Kittens and elderly cats are less likely to respond. If your cat doesn't react to catnip, it's entirely normal, and they may have other favorite toys or treats.

Cats cannot overdose on catnip in the same way humans can with certain substances. However, giving your cat too much catnip at once may cause them to become overstimulated or agitated. It's best to use catnip in moderation and observe your cat's behavior.

While cats often enjoy nibbling on catnip leaves, it's best to offer it in small amounts as a treat. Catnip should not replace your cat's regular food, and excessive consumption may lead to an upset stomach.

Kittens under three months of age typically do not respond to catnip. Sensitivity to catnip usually develops when they are a bit older, typically around 3 to 6 months of age. Until then, it may not have any noticeable effects on them.