Peptide half-life chart

What does half-life mean for a peptide?

A peptide's half-life is the time it takes for the amount in your blood to fall by half. If semaglutide's half-life is about 1 week, then a week after a dose about half is left, and after another week about a quarter¹.

Half-life is an average from a study group. Labels give a typical figure, and yours may be a little shorter or longer. It also only describes how fast a peptide leaves the blood. That isn't always the same as how long its effects last, which is covered further down.

Peptide half-life chart (humans vs animals)

Most peptides in the chart were measured in people. BPC-157 and TB-500 have animal figures only, and CJC-1295 without DAC has none. The GLP-1 figures come from section 12.3 of each US prescribing information. Research peptides are listed only where a published study gives a number.

How long does a peptide stay in your system? The 5 half-lives rule

About 5 half-lives. By then about 3.1% of a dose is left, which is the usual point for calling a peptide mostly out of your system. Each half-life removes half of what remains, so the amount drops fast at first and then more slowly.

The labels agree with this rule. The Ozempic label says that with a half-life of about 1 week, semaglutide stays in the circulation for about 5 weeks after the last dose¹. The Wegovy label says about 5 to 7 weeks after the last injection of 2.4 mg or 7.2 mg². It also says to stop Wegovy at least 2 months before a planned pregnancy because of semaglutide's long half-life².

This is about how much is left in your blood. It isn't the same as how long a drug shows up on a test, and it doesn't tell you when it's fine to start something else. Ask your prescriber or pharmacist about timing.

Why do some peptides last minutes and others a week?

Mostly, it's how well a peptide is protected from being broken down and cleared. Natural GLP-1 lasts only 1.5 to 2 minutes because enzymes in the body break it down fast⁶. The longer-acting GLP-1 medicines are built to avoid that. Some of them stick to albumin, a protein in your blood, which slows how fast they are broken down and filtered out:

• Semaglutide: albumin binding is the main reason its half-life is long, and it is also protected from the enzyme DPP-4¹.
• Tirzepatide: a fatty acid chain lets it bind albumin and makes the half-life longer³.
• Liraglutide: it resists the same enzymes, and its molecules cluster together under the skin, which slows absorption. That gives about 13 hours, suited to once-daily use⁶.
• CJC-1295 with DAC: it carries a chemical group that attaches it to albumin in the blood. In rats it was still in the blood after 72 hours¹⁴, and in people its half-life was 5.8 to 8.1 days¹³.

Peptides without that kind of protection clear in minutes. Tesamorelin's half-life is 8 to 11 minutes^9–10, and sermorelin cleared in about 4 minutes during an IV drip¹¹. BPC-157 holds up in gastric juice in a test tube, but in animals it is gone from the blood in minutes, which FDA's reviewers put down to enzymes in the blood and tissues¹⁷.

Why does the same peptide have more than one half-life?

The number can change with the product, the route, the dose and who was studied. Tesamorelin is a clear example. Its half-life was 8 minutes for Egrifta SV and 11 minutes for Egrifta WR, each measured in healthy adults after one dose under the skin^9–10.

• Who was studied. The Mounjaro label gives tirzepatide about 5 days. The Zepbound label gives about 5 to 6 days in people with overweight or obesity^3–4.
• Route and dose. In rats, BPC-157's half-life was 15.2 minutes after an IV dose, but 7.9 to 29.7 minutes after injection into muscle, rising with the dose¹⁶.
• How it was measured. The sermorelin figure of 4.3 minutes comes from a steady IV drip¹¹. A review gives a wider range of about 10 to 20 minutes in humans¹².

So the chart names where each figure came from, and shows both when two sources differ.

Is half-life the same as how long a peptide works?

No. Half-life is how fast a peptide leaves the blood, and its effects can be shorter or longer than that. Growth hormone peptides are a good example.

• Ipamorelin has a half-life of about 2 hours. In the same study, the growth hormone it released peaked at about 40 minutes (0.67 hours) and then fell away¹⁵.
• CJC-1295 with DAC has a half-life of 5.8 to 8.1 days. After one injection, growth hormone stayed raised for 6 days or more and IGF-1 for 9 to 11 days. After several doses, IGF-1 stayed above baseline for up to 28 days¹³.

For the licensed medicines, the label is the place to check how the dose schedule was set.

What is the half-life of BPC-157 and TB-500?

No one has published a human half-life for either. FDA reviewed both in 2026. It found no human data on how BPC-157 moves through the body (pharmacokinetics) by mouth, injection under the skin, nose or skin, and no human studies of TB-500 at all^17–18.

BPC-157 in animals: a 2022 study measured a half-life of 15.2 minutes in rats and 5.3 minutes in dogs after an IV dose. After injection into muscle it was under 30 minutes in both species¹⁶.

TB-500 in animals: no half-life has been published. In horses given 10 mg under the skin, blood levels peaked 1 to 2 hours later and were too low to measure by 6 to 10 hours¹⁸. That study was designed to build a doping test, not to measure half-life.

Any human half-life for these peptides that you see online is an estimate, not a measurement. For more on how the two compare, see BPC-157 vs TB-500.