Understanding your estimated medication levels

What the chart shows

Each time you log a dose, Reko adds it to a running picture. After an injection the amount in your body does not jump to a peak and drop away. It rises slowly, reaches a high point, then falls slowly. The next dose arrives before the last one has gone, so the doses add up.

The chart draws that overlap. You see the rise after each dose, the gradual fall, and how the line settles into a steadier pattern if you keep a regular schedule.

How the estimate is worked out

Reko uses a one-compartment model. It treats the body as a single pool the medication enters and leaves. It has two stages:

1. A slow rise. After an injection the medication is absorbed gradually, so the curve climbs rather than spikes.
2. Elimination. Then the body clears it, and the curve declines.

The speed of each stage comes from the compound's published absorption and elimination half-lives. A half-life is the time it takes for the amount to fall by half. Each compound in Reko has its own values.

Numbers for a specific medicine belong on its official label. The U.S. labels say that semaglutide (Ozempic, Wegovy) has an elimination half-life of approximately 1 week, with steady state after 4 to 5 weeks of weekly doses on the Ozempic label. Tirzepatide has a half-life of approximately 5 days on the Mounjaro label and 5 to 6 days on the Zepbound label, with steady state after 4 weeks of weekly doses.

What it cannot tell you

• Your own body. Size, metabolism, other medicines and many other things change how you handle a drug. The model uses published figures, not yours.
• What your blood holds today. Only a laboratory test can measure that, and these medicines are not normally monitored that way.
• Whether the medication is working. The curve describes an estimated amount. It does not describe an effect.
• Anything about doses you did not log. Missing or wrong entries change the curve. Reko lets you correct any dose on any date.

Using it well

Log each dose when you take it, with the real amount. Then put the curve beside the rest of your record: side effects, weight, how you slept. Over several weeks you may notice patterns, such as when you tend to feel worse in relation to a dose. That is a note to take to your prescriber, not a conclusion.

Reko never suggests a dose or a change to one. The curve is there to help you see your own record, and the decision stays with you and your prescriber.

For other compounds

The same method applies to the other compounds in Reko, each with its own published half-lives and its own units. Each also shows a plain regulatory status, so you can see what is and is not an approved medicine.

See the free tools, or Download Reko.

Is this the same as a blood level?

No. It is a calculation from your doses. A blood test measures what is actually in a sample.

Why does my curve look different from someone else's?

Different doses, different timing and different compounds give different curves.