I have been taking magnesium threonate (I'll shorten it to MGT in this message) for almost 3 weeks. Although I take only 2/3 of the recommended dosage, I've had some real improvements. If you Google MGT, there's a ton of info. In short, it was developed over 10 years at MIT and is the only MG that readily crosses the blood brain barrier. I've been taking the Life Extensions brand, Neuro-Mag, which I got from Amazon. From what I've read, LE and Swanson's get the MGT from the same source. I think there are 5 or 6 brands of MGT now. They all seem to be the same dosage with the exception of Sabre Science. Theirs is a powdered MGT that is combined with inositol. I was able to sample this product, but I felt really dragged out from it and had unrefreshing sleep. I think it's the inositol that doesn't agree with me. However, at the wholistic pharmacy where I got the Sabre Science sample, they are getting really good customer reports of kids with ADD and ADHD being able to focus better with that product. For about the 1st week I took MGT, I experienced a wonderful euphoria and powerful mood boost. I no longer experience it to that degree (rats! I like euphoria), but have retained a subtle, even mood boost that lasts all day. After 2 or 3 days, I started getting a little relief from my fibromyalgia pain. I already take lots of magnesium glycinate/malate plus some other forms, so I don't think the pain relief is from just increasing magnesium. I think the pain relief is from this specific form. However, I've read only one other report of someone experiencing pain relief from this supplement. So this effect might be uncommon. I really didn't expect this, but my sleep has really improved although I'm taking it in the morning and the early afternoon. My sleep quality is better, and I seem to be dreaming more and having better recall. At first my dreams were fantastical and extremely vivid and detailed, but that effect diminished. I'm still dreaming a lot, though. I have not noticed any improvements in concentration or memory. For me, it's more like increased mental alertness. I feel like my brain is more awake. I have not been successful in taking the full dose although I'll experiment again later. When I've tried it, I've felt even better during the day, but it's had a negative effect on my sleep. I've read every user review I could. From what I can gather, how people react to MG3 is highly variable. I'm sure it has to do with individual neurochemistry. Some people have not noticed any effects from taking MG3. There's a lot of excitement and buzz about this supplement, but some people are choosing to wait. No human trials have been released yet, and the long-term safety is unknown because it's so new. A study is supposed to come out sometime this year. I've read the most customer reviews on Amazon, Iherb, and Swanson Vitamins. Other reviews come up if you Google magnesium threonate reviews.