There is one specific symptom it is useful for: difficulties in processing blood sugar into ATP energy, where it helps by replacing with energy derived from breaking down stored fat. Over my (9 now, I think) cases I’ve encountered other fatigue symptoms, including one that was really an iron deficiency and one I suspect was “post-exertional malaise”, the creatine did nothing for them.

Creatine is pretty safe though, your body makes some naturally all the time, if you took a bucketload on the reg it might gratuitously let you burn too much fat doing exercise and then starve in a famine.

I would say it’s worth trying once – take say 4 scoops, it’ll take effect within 20 minutes, if that clears it up yay, take it every day and it’ll burn fat to keep you on until the symptom clears, if it makes you feel a bit better but not totally try some more until you find your level, if that’s not it sorry but maybe suggest it to other people with fatigue.