Semaglutide Half-Life Calculator for Ozempic, Wegovy & Compounded Semaglutide

About 1 week. The FDA prescribing information describes injectable semaglutide's elimination half-life as approximately 7 days, and this calculator uses that value for every shot you enter. Because the number belongs to the semaglutide molecule, it is the same whether you take Ozempic, Wegovy, or compounded semaglutide. A 7-day half-life means the estimate for a single dose halves each week: roughly 50% left at day 7, 25% at day 14, and so on down the line. That slow fade is also why weekly shots overlap and build up rather than clearing fully between doses. The tool turns that published number into a curve from your own dates, so you can see where a dose sits on any day without treating it as a lab reading.

Most of a dose is gone in about 5 weeks. With a half-life of about 1 week, roughly 97% of a semaglutide dose has cleared after five half-lives, and the FDA labels note the medicine stays in circulation for about 5 to 7 weeks after the last dose. Half of the last shot's estimate fades in the first week, three quarters by two weeks, and only a few percent is left by week five. Scrub this calculator's timeline forward past your final shot to watch your own estimate drop toward the bottom of the chart. When the appetite effect eases is a separate, personal question and can run on a different clock than the math, so treat the curve as background rather than a signal to change anything.

Yes. The roughly 1-week half-life is a property of the semaglutide molecule, so the calculator uses the same 7-day value for compounded semaglutide that it uses for a branded pen. Choose your dose and dates exactly as you would for Ozempic or Wegovy and the curve is drawn the same way. What the calculator cannot know is anything specific to how a given compounded prescription was prepared or how your body takes it in, which is one more reason the line is an estimate for learning and not a measurement. For anything about your compounded medicine, its strength, or its schedule, follow the instructions you were given and ask the pharmacy or prescriber that provided it.

Using the label's 1-week half-life, about 5 weeks. Half of the last dose's estimate is gone in 7 days, three quarters by 14, and roughly 97% by 35 days, which is the five-half-lives mark most people mean by mostly cleared. The remaining sliver keeps shrinking but never reaches an exact zero on paper. The GLP-1 half-life calculator shows the same fade next to tirzepatide if you want to compare. Whatever the chart shows, when to expect changes in appetite or weight after stopping is individual, so keep those questions with your prescriber rather than reading them off the curve.

Because a week only clears about half of each dose, so every weekly shot lands on top of what is left from earlier ones. Those leftovers stack for roughly four to five weeks until the amount cleared between shots matches the amount added, and the peaks and valleys settle into a repeating pattern. That build-up is expected once-weekly behavior, not a sign anything is wrong, and it is a big part of why the first weeks can feel different from later ones. The calculator draws that climb straight from the dates you enter, so if you have been on semaglutide longer than the default history, add earlier shots to see the fuller picture.

Commonly, yes. As the estimate declines over the roughly 5 weeks after a last dose, published follow-up research on semaglutide reports appetite returning and weight regain being common once the medicine is stopped. The calculator only shows the fading level from your dates; it does not predict how your appetite will respond, which varies from person to person. If you are thinking about stopping, tapering, or switching, that belongs with your prescriber, who can weigh your history and goals. Use the fading curve here as a way to picture the timing, not as a plan. For the same fade alongside tirzepatide, open the GLP-1 half-life calculator.