Half a tsp has a different effect than a full tsp. Half still seems to provide 100% PEM blocking, but doesn't have the full baseline symptom reduction that the larger dose has. It's hard to clearly identify PEM from elevated baseline, but the PEM should vary more during the day. Doses over 1 tsp don't seem to provide greater benefit; just several days longer duration. I think it would be better to take 1 tsp every three days than 4 tsp for six days. I'll wait for the PEM to clearly show up, then maybe I'll try 3/4 tsp, just to see the difference.