Steroids do have some fairly unpleasant side effects: horrible taste in your mouth, sleeplessness, feeling on edge/jittery/a bit ‘speedy’, stomach upsets/heartburn; and afterwards, fatigued, feeling bruised (and others).
But, if you take steroids very quickly after a relapse begins, they can work absolutely brilliantly. Last year, I had a relapse that I recognised as a relapse on the first day. I tested my wee to make sure I had no infection (vital), checked the steroids I had were in date (also vital), then started the pills.
I took them with a glass of milk, and made sure I had in date Omeprazole (to protect my stomach), had some liquid gaviscon and extra strong mints laid in (oesophagus protection and nasty metallic taste deterrent).
They worked brilliantly. I’d had my left leg behaving very badly (it’s normally my ‘good’ leg); it wouldn’t move at all, the foot drop on my right leg had spread to my left. It basically meant I was unable to walk at all and transfers from wheelchair to anything (bed, chair, shower chair) were very difficult and a tad dangerous. Within days my left leg felt better, it started picking up again. To my utter surprise, even my right foot started lifting almost perfectly. This amazed my neurologist, who checked his records from 7 years earlier - he’d never seen long established foot drop improve like that. (This improvement didn’t stay quite as good as this, but it’s still slightly better than before.)
Steroids, in my opinion, if taken soon enough can be worth the side effects. But they are unreliable. Sometimes they don’t work very well, or not as fast as you’d like. If you take them 3 or more weeks into the relapse, I don’t think the benefits outweigh the side effects. But I would take them everytime if I catch the relapse soon enough.