Thanks, I'll keep that in mind. I actually found a really good info on supplementing B1 (mainly TTFD) from @mostlylurking -- now I can handle more than before, around a 100mg a day; but still under observation on how it's gonna feel like for days/weeks to come for me. 'Cause now I've totally stopped taking Niacinamide and my eye bags are starting to decrease along with the dark circles (it's not that dark though).No recommendation, no "better", you have to try them all...
you also have to find YOUR cofactors before concluding it comes from the form you take...
Also the dose...
And if you have a sulfur issue, rub Mg sulfate (the famous epsom salts) on your skin, or in bath.
Sullfur intolerance comes from a sulfur deficiency, so transdermal is the way!