What A Home Meter Cannot Tell You

A glucose meter looks like an instrument that settles arguments. Used to judge a supplement over a few mornings, it mostly manufactures them.

What moves a reading that has nothing to do with a capsule. How you slept. Whether you are fighting something off. Stress on the morning of the test. How hydrated you are. What time you ate last night and what it was. Whether the strip came from a new pot. The meter's own tolerance, which is wider than most people assume.

The size of ordinary noise. Two fasting readings taken on consecutive mornings in the same person can differ by several points with nothing having changed at all. If your supplement test is looking for a difference of that size, the test cannot answer the question.

Why this is worse than useless. Because it cuts both ways. A reading that happens to fall gets credited to the capsule. A reading that happens to rise gets blamed on it. Neither conclusion is earned, and both feel convincing at the time.

What a meter is actually for. Managing a diagnosed condition, under the direction of the clinician who prescribed it, over patterns rather than points. That is a serious job and it is not this one. If you own a meter for that reason, your clinician's instructions outrank anything on any supplement website, including this one.

A better test if you want one. Pick something you can notice without equipment and track it in one line a day. The afternoon pull. Whether the flat patch after lunch turned up. How many times the biscuit tin got opened. Those are noisy too, but over four weeks the pattern is readable in a way three meter readings never are.