It's 3 days since my iron infusion and I've been sleeping like a log, which is very unlike me.
Last time I had an infusion my ferritin level was probably around 25, which is definitely too low, and it took over a week for me to notice a difference. My level prior to Thursday was ~65, so maybe that's why the improvement is sooner?
The infusion clinic was pretty odd; hearing nurses (and the pharmacists at the nearby pharmacy) tell people about how they should start feeling like they have more energy soon, that for some it's a huge difference. It almost seemed like a cult which I've joined and now want to tell everyone about.