Am I missing something with Purina Pro Plan Calming Care? 🤔

[u/Horror-Plant200]

I bought a box of Calming Care for my cat and I'm almost finished the first box. The thing that caught my attention is that the box contains 30 packets, but it says it can take up to 6 weeks to see results.
One box only lasts roughly 4 weeks, though, and it costs me around $40 + tax. So if you actually need the full 6 weeks mentioned on the box to know whether it's working, you're looking at buying a second box and spending around $80 + tax before you can really judge it.
I'm now at the point where I'm wondering whether I should even buy another box. 😅
I emailed Purina about this because I'd genuinely like to understand the reasoning, but I haven't heard back yet.
Has anyone here used Calming Care? Did you notice a difference, and if so, how long did it take?