My doctor uses hair analysis to develop a supplement regimen, and it can be a valuable tool, as it looks at the mineral trends, the ratios of the minerals in the bottom. Certain mineral patterns and ratios of high or low are associated with certain physical problems. It can come back saying to consider low adrenals, low thyroid, etc., though it is not considered conclusively or quantitative (ie. it's not the same as bloodwork showing actual low thyroid or low cortisol levels). Many chiro's do hair analysis as well. The lab my doc uses is Analytical Research Labs in Arizona (602) 995-1581. It is one of two labs recommended by Mercola.
BTW, hair analysis will not necessarily show stores of heavy metals like mercury, etc. Your body on excretes what it can handle (that's what my doc says). So if your body is mercury toxic for instance, then it puts the mercury in the mineral receptor sites. And it then hoardes it because things are so out of whack that your body is unable to handle it and excrete it. Hence, to detox, you would promote balance, introduce chelators to pull it out, and replace it with other necessary minerals. That is why many effective detox programs will have you take a mineral supplement, to fill in the gaps from the mercury that is being pulled out.
So, it should make sense to you that some people will be already excreting somewhat and it may show up, while others will be hoarding and toxic though none shows up at all. And assumedly during detox, the hair from that time would contain a certain amount of the heavy metals you are trying to detox. Gross.
And just to continue with this train of thought, my doctor has also found this true with stool samples for instance, that candida, parasites, etc. may not show up on a stool sample until AFTER you begin treating for them. IE. that they may not show up until you have strengthened the body and given your body things to help it get rid of them. Of course there are also people who are so infested that they show up anyway. But this does explain why some people may not show something that they appear to have a problem with. In my own case, my hair analysis shows high levels of aluminum, not reading any mercury at all, but when we did muscle-testing, we found that the mercury was the worst metal for me right now. Interesting!
