Many men have been asking me, "What is Concentrace?" Concentrace Trace Mineral Drops is a product that I have used from time to time, because it a source of 1) ionized minerals for maximum absorption and 2) a broad array of minerals, including the trace ones that the body needs in minute amounts.
Our modern soils are so depleted of minerals of virtually all types that this certainly seems attractive, since there are many common issues that can interfere with mineral absorption, including low hydrochloric acid levels in the stomach, black tea, soy, etc., etc. In other words, quite easy to still end up deficient even if you are conscioustious and eat a well-rounded, whole foods diet.
The problem that you'll find with Concentrace Trace Minteral Drops is to out just exactly how much of what minerals is actually contained in the standard dosage prescribed on the bottle. However, in an obscure location of their site, I did find the Concentrace Analysis Summary, which has a complete list of mineral concentrations.  You can see some of this in Table I below at the bottom of this page.
The only problem with this list, for most of us non-chemists, is that it is in parts per million. The standard dose, as directed on the bottle, is 40 drops or about 1/2 teaspoon, so we need to somehow convert the ppm to a 1/2 teaspoon. The key conversion factor that I am assuming is that 1 ppm is equal to 1 mg/L. This should be a reasonable assumption and is quite common with water-based solutions, but keep in mind that I have not officially verified this yet with the parent company Trace Minerals.
However, I do think this seems to be a pretty reasonable assumption as the total magnesium that I come up with is 250 mg, which is reasonably close to what is on the bottle. Other numbers, such as chloride, are fairly close as well.
So the bottom line is that their concentrations may have changed a little over time, but I still think we can draw some interesting conclusions, both positive and negative:
1. Magnesium. Concentrace is clearly a FANTASTIC choice of easily absorbed magnesium. Magnesium can help with sleep, which in turn can improve testosterone levels. Magnesium can also help improve heart disease, which can help erections. Magnesium is simply a ubiquitous molecule that is involved in 100's of different metabolic pathways.
2. Boron. Getting about a mg of ionic Boron is excellent as well. As I document in my link on Testosterone and Boron, you get about 1.5 mg/day of boron on average probably and the experts recommend up to about 3 mg/day. So this amount should be a nice addition to your (hopefully) well-rounded, whole foods diet.
3. All Other Minerals. What was surprising is the very low amounts of virtually all other standard minerals. For example, the daily requirement for potassium is about 4,700 mg, but 40 drops will only provide about 5 mg. Calcium and selenium are also less than a mg. Thus, with the exception of magnesium and boron, Concentrace Trace Mineral Drops provides very low amounts, well below 1% of RDA or AI.
4. Exotic Minerals. Concentrace does provide some of the more exotic minerals that the body does need in trace amounts. Rubidium is a classic example. There is no RDA or AI for rubidium, yet your body does use it in trace amounts for, among other things, the CNS (Central Nervous System). Studies have shown that low rubidium levels can negatively lead to mood disorders and depression in dialysis patients, who are known to have depleted rubidium levels. 
However, even here, it seems hard to get excited, because Concentrace provides such a low dosage. We eat between 1 mg and 5 mg per day of rubidium in our foods. Even coffee and tea have a good supply. The very minute amounts in 40 drops seem, quite frankly, to be almost negligible.
5. Heavy Metals. CAUTION: And here is where I see the problem with the Trace Mineral formulation: it has a number of heavy metals, including cadmium, arsenic lead, mercury and aluminum. Now, admittedly the amounts are very small. But I do not think of all the dosages can be so easily dismissed. For example, the dosage of arsenic in Concentrace is about 2.07 parts per million, which is in the area of rice, something that many experts are concerned about.
So, yes, it is a great source of magnesium, but you could simply use ZMA as a well-absorbed alternative and get a nice dose of zinc as well. I simply do not see the big advantage in using Concentrace daily and risk some of the heavy metal exposure.
1) "Concentrace Analysis Summary", http://themineralfoundation.com/documents/ research/ConcenTrace%20Analysis%201.pdf
2) Kidney International, 2001, 60:1201 1201, "Depression in dialysis patients: Rubidium supplementation before other drugs and encouragement?