Same here, though maybe I got benefit for a bit longer. It had a remarkable head clearing effect which unfortunately wasn't sustained. Also a remarkable energy increase for a while which I had attributed to D-ribose, but that too disappeared despite continuing the D-ribose. I tried increasing the boron dose but not only did this not help, it started to make me feel worse. Eventually I had to stop the extra boron though have continued with a trace mineral preparation containing 0.7 mg B. At first I thought the response was part of the refeeding syndrome which Freddd has been talking about recently but now I think this is less likely. It could be that in repleting boron I had just exposed some other limiting factor. I did try various other minerals, also increasing B2, but none of these helped. If the problem is just some other missing nutrient, it is hard to understand why the boron started to become a real problem - one would just expect it to do nothing. It felt much more like an active turning off - as if some feed-back inhibition had kicked in. I have been thinking about thyroid hormone a lot lately as my last blood tests show a definite slide into mild hypothyroidism. Maybe the boron was stimulating T4 for a while and what has kicked in is increased draining off down the rT3 pathway. Certainly my rT3 is elevated. Am about to try some slow-release T3. It will be interesting to see if it feels anything like the effect I once had with boron.