Why and when to retest

A first test tells you where you are. It can’t tell you whether the changes you make afterwards are working. That’s what the retest is for.

Why about 120 days?

Red blood cells live for roughly four months, and the fatty acids in their membranes change gradually as new cells replace old ones.[source pending] Testing again too soon mostly measures the old picture. That’s why we usually plan the main retest around 120 days after the first test.

What a retest is good for

• Checking whether your food and supplement changes show up in your blood
• Adjusting the plan based on what moved and what didn’t
• Deciding what to keep doing, and what to drop

What it isn’t

It isn’t a pass or fail. Numbers move at different speeds for different people. The point is to learn from the change, not to hit a target by a deadline.

How retesting works in our programs

• 6 Weeks: a reminder when it’s time on the test timeline.
• 12 Weeks: we support the retest on the test timeline, not tied to week 12.
• 12 Weeks + 9 Months: the main retest is planned around day 120, and later retests can be added.

See the programs for details.

Sources

1. [source pending] Source needed: red blood cell lifespan (~120 days) and how fast membrane fatty acids change