Strips turn Purple - but take several hours?
 

Hello,

Anybody else experience this? Ketone strips turn Purple but after quite awhile has passed? (No change 40 secs after)

Yes, they do turn purple after some time, but that is not an indication of ketones. The color after 40 seconds is the only valid reading.

Hmmm, I never knew to wait 40 seconds!! If no change right away I was pitching them. Have to try again, now. LOL


Ok, look at this. This says "15 seconds." From NutritionAdvance.com

How Do Ketone Strips Work?

You can probably guess the finer details, but if you want to know how to use ketone strips, the process looks like this;

Take a urine sample in a clean container/jar of some sort

Hold the end of the strip in the urine for a few seconds

Shake the strip to remove any excess “liquid” before removing from the container

Wait 15 seconds until the ketone strip changes color

Comparing the color of your ketone strip to the color chart will let you know if you’re in ketosis (and how deeply).

Use fresh test strips too for accuracy.

Some say 15 seconds, others say 40.

I don't bother with the container and just try to catch midstream.

What PaCarolSue said ^^^
The instructions on my strips say to compare the reading with the legend between 1 and 2 minutes after wetting the reagent pad. Any reading after 2 minutes is invalid.

slightly off topic, but I was getting really discouraged because my strips wouldn't turn colour after more than a week on the diet - then decided to buy new. (the other ones were in my medicine cabinet in the bathroom for at least 6 months). New batch - purple right away!