I took it for a month, didn’t feel any difference.
I know what you mean.
Its always hard to tell if you actually feel an improvement when there is actually some improvement because that improvement is so incremental & subtle.
One way to test it is to stop the supplement suddenly & see whether you notice a change for the worse. What do you expect from taking spirulina? I dont know how does this supplement help but if you notice a lack of a particular wellbeing, then you know its working. You can try with other supplements you know that its working for you.
you can try this with other so called improvements or tweaks.
Eg, for those those hifi audiophile enthusiasts, usually you try to discern a sound improvement when I try out a new gadget which is difficult. But the ment I remove the tweak, the difference is obvious. Hence then you can decide if the tweak actually works for you