Catnip, Silver Vine, Tartarian Honeysuckle or Valerian Root are known to be cat-attractant plants. As far back as 1768, English botanist Philip Miller noted that cats were uniquely obsessed with the plant when it was withered, describing them "rolling, tearing, and chewing" at the leaves.
At least two scientific theories explain why cats respond so intensely to these plants, and why some secret options work better than others.
Hypothesis 1: the chemical cocktail
For a long time, catnip (Nepeta cataria) was the gold standard. Its secret weapon is nepetalactone, a strong chemical compound that binds to receptors in a cat's nose, triggering a response. However, roughly one-third of cats are genetically "immune" to catnip and won't react to it at all.
In 2017, a study by researcher Sebastiaan Bol found that a larger population of cats responded to Silver Vine, including about 75% of the cats that were completely immune to catnip.
The question at the time was: How does Silver Vine outperform catnip when catnip actually contains 40 times more attractant chemicals (cis-trans nepetalactone)?
A 2021 study published in the prestigious journal Science Advances solved that mystery. Catnip relies almost entirely on a single, massive chemical note (nepetalactone), for which about a third of cats are genetically non-responsive. Silver Vine, on the other hand, unleashes a complex cocktail dominated by a cousin molecule called nepetalactol, alongside several other active compounds like actinidine and iridomyrmecine.
When a cat rubs against Silver Vine, it damages the plant, releasing this diverse chemical blend. This multi-layered cocktail successfully activates the feline brain's reward systems even if the cat's genetic makeup makes them blind to catnip.
The other two alternatives, Valerian Root and Tartarian Honeysuckle, don't have catnip's exact molecules, but they contain actinidine. This is a close chemical relative that fits into the very same olfactory (scent) receptors in the cat's brain.
It concluded that chemical complexity rather than quantity was a primary factor to determine behavioural effectiveness in cats. This chemically more diverse blend of compounds present in Silver Vine could thus compensate for its lower total dose of nepetalactone.
| Plant (Part Used) | Nepetalactol | Nepetalactone | Actinidine | Iridomyrmecine | Dihydroactinidiolide |
|---|---|---|---|---|---|
| Silver Vine (Leaves & Fruit Gall) | +++ | + | ++ | ++ | ++ |
| Catnip (Leaves) | — | +++ | — | — | — |
| Valerian Root (Root) | — | — | ++ | — | — |
| Tartarian Honeysuckle (Wood/Bark) | — | — | + | — | + |
Note: +++ indicates highly dominant, + indicates present, and — indicates absent.
Hypothesis 2: real world versus laboratory conditions
The second reason some plants seem more effective than others comes down to how we study them. A laboratory is a constrained environment where cats don’t have other options than to force engagement with the plant. In such experimental design, both catnip and silver vine show high success rates.
A 2026 study took a closer look at the free-choice conditions. It tested cats in natural environments where they were entirely free to approach, investigate, or ignore stimuli. In that free-conditioned environment, cats' behavioural activation depends not only on sensory detection of Catnip or Silver Vine, but also on the probability that detection leads to voluntary engagement.
The researchers discovered that when cats have a choice, they ignore catnip far more often than they ignore Silver Vine. Because Silver Vine possesses a much more complex compound, it manages to cut through background environmental distractions. It doesn't mean catnip doesn't work; it just means that under free-choice conditions, the complex cocktail of Silver Vine is far more reliable at grabbing and holding a cat's voluntary attention.
Going further
When cats chew and roll on these plants, they transfer molecules like nepetalactol onto their fur. The researchers discovered that this chemical family doubles as an incredibly potent, natural mosquito repellent. As such, by getting high on Silver Vine or Catnip, wild felines protect themselves from deadly insect-borne diseases.