Most of the stuff I’ve tried that worked usually has an immediate or overnight effect. Notably Low Dose Naltrexone was overnight, Low Dose Abilify was near immediate. I believe this is due to their immunomodulator properties. So I studied psychopharmacology and focused in on finding weaker ligands than typical as a way to try and safely modulate my immune system. I landed on Modafinil in the morning and Amitryptiline at night, both off label treatments for the probably related dysautonomia.
The N of 1 with many overlapping signals and medications was of course very noisy but I treated it like a ML optimization problem. I could tell it was likely beneficial within the first week even with the small dose. I probably could have statistically determined it was working within a few months but I was distracted by work so it took a little longer to be sure.