I’ve taken Vitamin B6 in dropper form and currently take Vitamin B12 sublingual daily (no B6 supplementation for probably the last year).
I can say that a drop or 2 of B6 did make me feel different pretty quickly whereas the B12 does not. I don’t know about B3 but I would say the B6 caused improved mental clarity and also possibly calmness and maybe ED. I may have been experiencing B12 deficiency at the time so that could have skewed things. If you do decide to try B6 drops I would proceed VERY slowly and VERY cautiously. Take one drop the first time you do it and wait an hour as if it’s a hallucinogenic drug. After I saw how strong it could be I would not have dared take a whole vial at once. It’s strong.
YMMV.