Millie, a gram of L-Tyrosine is sufficient in my experience to renew the neuro buzz. Macro the formula ninja would know best, though.
HDT used to make a great "smart drug" product circa 1999 with L-Tyrosine, DMAE, ginkgo, ginseng, B vitamins, and a few other goodies - I think this would have been great to stack with Thermorexin. I miss it.
Oh, and I'm still loving Thermorexin. I went up to four pills today, and I think I'm going to stick with three in the future - I had my last dose six hours ago, it's almost midnight, and I still have a tremendous urge to furiously clean my room and go running.