The test states that a test line (left) that is lighter than the control line (right) means that one's FSH is at a sufficiently low level and therefore indicates adequate ovarian reserve. If the line is the same color or darker, then one should follow up with a doctor because it may indicate diminished ovarian reserve (and hence diminished fertility). According to one representative at Fertell, the test is calibrated to 10mIU/ml of FSH in serum...so having a test line identical in color to the control line would be similar to having an FSH of 10. For fertility purposes, an FSH of 10 is really on the precipice between sufficient and insufficient ovarian reserve. To my mind, my test line looked a little bit lighter than a possible serum FSH of 8.75, but it's close and was a few months prior, so basically accurate.
In January of 2011 I took a Day 3 First Response FSH urine test and got this result:
To my eyes, it looks the same, perhaps even a little bit lighter than the Fertell test I took a year ago. I have to assume (although I have no proof and cannot track down any information on this) that the First Response FSH test is calibrated in a similar way as the Fertell test, to about 10 mIU/ml, which is why the results appear similar to the Fertell FSH test. I did take a few more First Response FSH tests again in February and March on Day 3 to check for any fluctuation (always using FMU as directed), and I got about the same lines on all the tests, so they do appear to be consistent.
My feeling about the First Response FSH product is that it is somewhat reliable, but it ultimately only gives a woman half the story. The problem is that checking FSH alone tells a woman nothing about her estradiol level and estradiol MUST be checked in conjunction with FSH, because an elevated estradiol can falsely lower a woman's true FSH. This is actually true in my case, because I have a slightly elevated estradiol level according to my blood serum tests, therefore my FSH number is acutally unreliable, whether it is measured via urine or blood serum. If I did not know about my elevated estradiol, I would have assumed that my FSH was completely fine and even rather low from this urine test, which it is not.
So in the final analysis, my review of this product is that it is adequate in testing one's FSH level and appears to be consistent with other brands and even with serum results. If one gets a dark line on the test, it is absolutely a good idea to follow up with a doctor. If you get a light or average line on the test, it can unfortuantely mislead a woman into thinking her fertility and ovarian reserve are adequate and therefore prevent her from seeing a doctor, because it does not and cannot test for estradiol levels, which can mask a woman's true FSH number. An FSH test by itself is ultimately not helpful for this reason.
