--- title: "Semaglutide Half-Life Calculator — When It Clears | GLPMate" url: https://glpmate.me/tools/half-life-calculator/semaglutide language: en description: "How long does Semaglutide stay in your system? Its half-life is ≈ 1 week (about 7 days) — most of a dose clears in about 35 days. Free calculator, no signup." updated: 2026-07-24 --- Free tool · no signup # Semaglutide half-life calculator How long does Semaglutide (semaglutide) stay in your system? Its half-life is ≈ 1 week (about 7 days) — enter your last dose to estimate what's left today, and see it clear half-life by half-life. **See your real level, not just an estimate** GLPMate models your actual semaglutide level day by day from your real dose history — free. [ Download on the **App Store** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-half-life-calculator-semaglutide&adj_redirect_android=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_macos=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_windows=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235) [ GET IT ON **Google Play** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-half-life-calculator-semaglutide&adj_redirect_ios=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_macos=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_windows=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate) When was your most recent Semaglutide dose? Defaults to today. This estimates what's left from that single dose. Estimated Semaglutide remaining 100% Right after a dose, 100% is on board. Pick your last dose date above to estimate today's level. _Half-life_ **7 days** _~97% cleared_ **~35 days** _Days since dose_ **0** How Semaglutide clears, half-life by half-life ~7 d 50% ~14 d 25% ~21 d 12.5% ~28 d 6.3% ~35 d 3.1% Days are counted from your last dose (7 days per half-life). After ~5 half-lives (35 days) only about 3% remains — effectively cleared. ## How long does Semaglutide stay in your system? The short answer: about **35 days** after your last dose. Semaglutide's elimination half-life is **≈ 1 week (about 7 days)**, and it takes roughly five half-lives for ~97% of a dose to leave your body. The table below shows the standard decay. Time since last dose | Approx. remaining 7 days (1 half-life) | **50%** 14 days (2 half-lives) | **25%** 21 days (3 half-lives) | **12.5%** 28 days (4 half-lives) | **6.3%** 35 days (5 half-lives) | **3.1%** ### The formula This is first-order elimination — the same math clinicians use: **remaining = 0.5 ^ (days since dose ÷ 7)** It's a single-dose estimate. If you've been dosing for a while, you start clearing from a higher accumulated level, so in practice it can take slightly longer than the single-dose figure — but ~5 half-lives from your last dose is the widely used rule of thumb. ### Why the half-life cuts both ways Semaglutide's long half-life is exactly why your level builds up over the first month and fades slowly when you stop. Understanding your own level — not just guessing — is what GLPMate's free [medication-level plotter](/tools/glp-1-plotter) and in-app curve are for. This page covers semaglutide, the active ingredient in Ozempic, Wegovy, Rybelsus. Looking for a specific brand? See the [half-life hub](/tools/half-life-calculator) for all medications. Source: FDA Prescribing Information clinical-pharmacology data for semaglutide products. Educational estimate — not medical advice. ## Related free tools [ **Medication-level plotter** Watch your estimated level build to steady state on your real schedule. Open tool → ](/tools/glp-1-plotter) [ **Dose calculator (mg ↔ units)** Convert prescribed mg to syringe units from your vial concentration. Open tool → ](/tools/dose-calculator) [ **All half-life calculators** Compare semaglutide, tirzepatide and every brand in one place. Open hub → ](/tools/half-life-calculator) ## Sources 1. FDA Prescribing Information (label) for each product — clinical-pharmacology sections — elimination half-life per active ingredient 2. First-order elimination model — remaining fraction = 0.5 ^ (time ÷ half-life) Last updated: 2026-07-24 FAQ ## Semaglutide half-life questions ### How long does Semaglutide stay in your system? Semaglutide's elimination half-life is ≈ 1 week (about 7 days). It takes roughly 5 half-lives to clear about 97% of a dose, so that's around 35 days after your last dose. A tiny amount lingers longer, but it's usually not clinically meaningful. This calculator estimates what's left on any given day from your last dose. ### What is a drug half-life, exactly? A half-life is the time it takes for your body to clear half of the drug. After one half-life 50% remains, after two 25%, then 12.5%, and so on. Semaglutide's 7 days half-life is why it both builds up gradually when you start and clears slowly when you stop. ### Why does Semaglutide take weeks to build up if the half-life is only 7 days? The same half-life that slows clearance also slows accumulation. With weekly dosing, each dose stacks on what's left of the previous ones until you reach a steady state — usually after about 4–5 weeks at a constant dose. GLPMate's medication-level curve shows this build-up on your real schedule. ### How does this calculator estimate what is left? It uses first-order elimination: fraction remaining = 0.5 ^ (days since dose ÷ half-life in days), with the half-life taken from Semaglutide's clinical-pharmacology data. It's a single-dose educational estimate — real levels also depend on accumulation from earlier doses, your metabolism and kidney function. ### Can I make Semaglutide leave my body faster? Not reliably. Clearance is set by the drug's chemistry and your own physiology — extra water, exercise or supplements don't meaningfully speed it up. If you need it out of your system for a procedure or pregnancy planning, that's a conversation for your prescriber, who will plan around the half-life. ## Track your Semaglutide level automatically. Free core. iOS & Android. [ Download on the **App Store** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-half-life-calculator-semaglutide&adj_redirect_android=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_macos=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_windows=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235) [ GET IT ON **Google Play** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-half-life-calculator-semaglutide&adj_redirect_ios=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_macos=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_windows=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate)