I'd do 5-7 days. This will let any oral just taken not show up.
B12 injected will show a huge effect, but oral is less absorbed.
B12 stays in the serum for about 72 hrs when injected.
Injected is 1000mcg all at once. This is why taking oral I think is better, because the injection just doesn't last long. Many doctors are switching to oral recommendations, but it is a slow process for them to do a "new thing".
Your target is 1000 or better on the test if you are supplementing. The test only reads to 2000, and some posters here keep their levels at that reading.
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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