Half-life tells you how fast a drug leaves your blood. It does not tell you how long it works, how long it is detectable, how often to take it, or when you will see a result.
Those are separate questions with separate answers, and for one molecule they can be weeks apart.
Semaglutide is the clearest example, because every one of its numbers sits in the label. It peaks 1 to 3 days after the injection. Its half-life is about a week. It stays in circulation 5 to 7 weeks after the last dose. It is injected weekly. Reaching the maintenance dose takes 16 weeks. The trials behind it ran up to 68 weeks.1
Seven numbers for one drug, from one day to over a year. Someone who knows only the half-life has one of the seven, and it is rarely the one answering their question. For BPC-157, the most searched compound we track, there is no human half-life at all.
What is a peptide half-life?
The time it takes for the amount in your blood to fall by half.
If a peptide has a half-life of 12 hours, then 12 hours after it peaks you have roughly half as much, at 24 hours a quarter and at 36 hours an eighth. The curve flattens as it goes, so clearance ends up taking several half-lives instead of two.
The definition stops there. It describes one thing, the rate of disappearance from plasma, and everything else people use it for is an inference laid on top. Some of those inferences do not hold.
The figure usually quoted is the elimination half-life, the terminal rate of decline. Some labels also give a distribution half-life for the faster initial drop as the drug spreads out of the bloodstream. When a source gives one number without saying which, it is normally the elimination half-life.
Why do some peptides last minutes and others a week?
The long ones were engineered to last. Semaglutide's label says so in as many words.
A peptide is a short chain of amino acids, and the body is efficient at taking those apart, so most peptides left in their unmodified state are cleared fast. Tesamorelin's 11 minutes sits far closer to that natural state of affairs than semaglutide's week does.
Semaglutide lasts a week because of a specific modification, and the Wegovy label names it. Section 11 states that "the main protraction mechanism of semaglutide is albumin binding".1 Section 12.3 says what that buys. Semaglutide "is extensively bound to plasma albumin (greater than 99%)", and that binding "results in decreased renal clearance and protection from degradation".1
Albumin is the most abundant protein in blood, so a molecule that clings to it spends most of its existence attached to something too large for the kidney to filter and tucked away from the enzymes that would otherwise cut it up. Only the small unbound fraction is available to be cleared at any given moment. Clearance is slow by design.
The label's choice of word carries the rest of it. Protraction means lengthening, so there was a shorter baseline to lengthen from, and a half-life turns out to be less a property of an amino acid sequence than a property of what was bolted onto it.
This reconciles two things people hear and cannot square, that peptides are destroyed in minutes and that semaglutide lasts a week. Both are true, and the difference between them was designed in.
It also explains why half-life figures do not transfer between compounds. Two peptides with similar sequences can sit orders of magnitude apart if one carries an albumin-binding modification and the other does not. A number borrowed from a related compound is not an estimate for yours.
Is there a peptide example rather than a pharma one?
CJC-1295 is the clearest one, because its nearest relative is tesamorelin.
Both are analogues of growth hormone releasing hormone. Tesamorelin's elimination half-life is 11 minutes.2 A 2006 trial in the Journal of Clinical Endocrinology & Metabolism estimated CJC-1295's half-life at 5.8 to 8.1 days.8 Same peptide family, same target, and a difference of roughly three orders of magnitude.
The paper's own framing explains why anyone bothered. It notes that therapeutic use of GHRH "is limited by its short duration of action", and CJC-1295 was built as a long-acting version of it. Whatever was done to the molecule, the 11 minutes became days.
The same paper measures duration of action against half-life, in people. After a single injection, plasma growth hormone rose 2- to 10-fold for six days or more, and IGF-I rose 1.5- to 3-fold for nine to eleven days.8 An effect on IGF-I lasting up to eleven days, from a molecule with a half-life of six to eight. The effect outlasts the drug, measured in the same study that measured the drug.
After repeated doses, mean IGF-I stayed above baseline for up to 28 days, and the authors describe evidence of a cumulative effect.8 Which is the answer to a question people ask in the other direction: things can build up. At a weekly interval and a multi-day half-life, each dose arrives before the last one has gone, and levels climb across the early weeks before settling. Semaglutide does the same thing, and that is why week one and week six are not the same experience on an unchanged dose.
One caution on the name. That half-life figure belongs to the compound the paper studied. Sellers list two different things under the CJC-1295 name, with and without the modification, and they are not the same molecule or the same half-life. Our comparison of CJC-1295 with and without DAC sets out which is which. Mechanism is the other thing to be careful about: the abstract retrievable here does not describe how the molecule achieves its long action, so this page does not state one.
What are the seven numbers people mix up?
Seven are in common use. Only the first of them is the half-life, and the rest get attributed to it.
| What you want to know | What answers it | Why it is not the half-life |
|---|---|---|
| How fast does it leave my blood? | Elimination half-life | This one is the half-life |
| When does it kick in? | Time to peak concentration, written Tmax | A drug can peak in hours and persist for weeks, or the reverse |
| When is it out of me? | Several half-lives, or the label's own washout figure | The label figure is sometimes longer than the arithmetic gives |
| How long does one dose keep working? | Duration of action | The effect can outlast the molecule by hours or days |
| How often do I take it? | The dosing interval on the label | Set by the duration of action and what people tolerate |
| Would a test find it? | The detection window for a specific assay | Depends on the test, the route and what the lab looks for |
| How much of the dose gets in? | Bioavailability | Unrelated to the half-life, and it can differ 50-fold by route |
| When will I see a result? | The trial endpoint | Usually months after the drug reached steady state |
The last two are where most of the confusion lives. The dosing interval is where the intuition fails hardest, and the reason is the row above it.
Why is the dosing interval not just the half-life?
Because the dosing interval is the gap between doses that a trial tested and a label recommends, and it is timed to the effect rather than to the molecule. Two approved drugs show how far apart those can sit.
Tesamorelin has an elimination half-life of 11 minutes and is injected once a day.2 That is a dosing interval roughly 130 times the half-life. The drug is gone from the blood within an hour and the label still says once daily, because tesamorelin works by prompting a pulse of growth hormone release. The molecule is a trigger, and what follows the trigger lasts far longer than the molecule does.
The gap between those two facts has a name. Duration of action is how long one dose keeps producing its effect, and it is a separate quantity from the half-life. For tesamorelin the two are wildly apart. For a drug that works by simply occupying a receptor while it is present, they sit close together. Nothing about a half-life tells you which kind of drug you are holding.
Semaglutide sits at the other end. Its half-life is about a week and it is injected once weekly, so the interval is roughly one half-life.1 Tirzepatide's half-life is about five days, and Mounjaro and Zepbound are both weekly.3 Liraglutide's half-life is about 13 hours and it is injected daily.4
So across four approved drugs in adjacent spaces, the dosing interval runs from about one half-life to about 130. There is no formula connecting them, and anyone deriving a schedule from a half-life is inventing one.
The reason is that a dosing interval comes out of a trial rather than out of a calculation. Someone picked candidate schedules, tested them in people, and the label records which one worked and was tolerated well enough to approve. For compounds with no trial behind them nobody has done that work, and a half-life cannot stand in for it.
How long does it take to clear?
It takes several half-lives. The rule of thumb everyone uses gives a shorter answer than one manufacturer's own instruction does.
The rule of thumb is that after five half-lives roughly 97% of a dose is gone, and that is why five half-lives gets treated as the point where a drug is out of your system. For semaglutide at a one-week half-life that comes to about five weeks, and the Ozempic label says semaglutide is present in circulation for about five weeks after the last dose.5 On that drug the arithmetic and the label agree.
Then the Wegovy label, same molecule at higher weight-management doses, says five to seven weeks.1 And both labels instruct discontinuation at least two months before a planned pregnancy.15 Two months is longer than either circulation figure and well past five half-lives.
Those two figures are answering different questions. The clearance arithmetic describes when the drug is gone, while a preconception interval describes how much margin a manufacturer wants on a decision where being wrong is serious. The label's figure is the one to follow, because it is the one with a regulatory review behind it.
Our guide on peptides, fertility and pregnancy covers that interval in detail.
How long is a peptide detectable?
Longer than most people expect in some cases, and the half-life will not tell you which cases. What the test is looking for decides it.
Detectability is the length of time a specific test can still find a specific molecule in a sample. It is not a measure of how much drug is left in you, and the molecule a laboratory targets is frequently not the drug itself.
A 2015 study in Drug Testing and Analysis gave five growth hormone releasing peptides nasally and tracked urine for two days.6 The results:
- GHRP-2 and one of its breakdown products were found for up to 47 hours.
- GHRP-6 was mostly excreted unchanged and found for up to 23 hours, while its breakdown products lasted only 12 hours.
- GHRP-1 was never detected as the parent compound at all. One of its breakdown products was found for up to 27 hours.
GHRP-1 is the case that defeats the question. A test looking for the drug would have found nothing at all, while a test looking for one of its fragments found something more than a day later. So "how long is it detectable" has no answer until somebody names the assay.
The authors state the detection window depends on individual metabolism, the form of the preparation and the route of administration.6 Three variables before you reach the compound itself. This was also one volunteer per peptide, given nasally rather than by injection, so the hours above are a demonstration that windows exist rather than a lookup table.
Is bioavailability the same as half-life?
No. Semaglutide is the same molecule with the same half-life by either route, and a fiftyfold difference in how much of it arrives.
The Wegovy label gives absolute bioavailability as 89% by subcutaneous injection and "approximately 1% to 2% following oral tablet administration".1 The elimination half-life does not change between those routes, because half-life describes removal and bioavailability describes arrival.
That is why oral and injected versions of the same drug are not interchangeable at the same number of milligrams, and why the oral products carry their own strengths and instructions. Our comparison of the Wegovy pill and Foundayo covers what each route asks of a user.
For anything sold as a capsule, spray or cream the same split applies, usually with no figure at all. A half-life says nothing about whether the dose got in. A blend is harder again, because it carries two or more half-lives at once, and our guide on why two calculators disagree covers what that does to an estimate.
How long until it actually works?
Usually months. The drug settles at its plateau long before the result arrives.
This is the question most people are really asking, and the half-life has almost nothing to say about it. Semaglutide shows the gap clearly. At a one-week half-life, blood levels plateau in about five weeks at a given dose. The label's escalation to the maintenance dose takes 16 weeks. The trials ran up to 68 weeks.1
So the pharmacology settles in around week five, the tested dose is not reached until week 17, and the outcome the drug is prescribed for was measured more than a year after that. Someone at week six wondering why nothing has happened is asking a question the half-life cannot answer, because the answer lives in the trial timeline rather than in the drug's clearance.
All of that is for a drug with trials behind it. For most of what is sold the time-to-result question has no measured answer either, and the absence tends to get filled with a cycle length from a seller's website.
Our guide on how long peptides take to work covers the outcome side properly. The half-life is not the route to it.
What if the half-life has never been measured?
Then any number you are handed is an extrapolation, a guess, or borrowed from a rat.
For a large share of what research sellers list there is no human pharmacokinetic study at all, and BPC-157 is the clearest case of it, because a regulator went looking and said so. The FDA's 2026 briefing document states it "found no human pharmacokinetic data for BPC-157 after oral, SC, nasal, or transdermal" administration.7 Not a thin dataset. None, by any route.
What circulates instead for BPC-157 is a figure of roughly 8 to 30 minutes, taken from rat studies. A rodent figure is not useless, and it is also not a human half-life. The gap between those two statements is where most confident arithmetic about this compound lives.
The consequence lands hardest on anything that takes a half-life as an input. Our guide on why two peptide calculators disagree sets out where the numbers in a half-life index come from and how many have no human source at all.
There are two practical consequences. A blood-level estimate built on an unmeasured half-life inherits that uncertainty whole, and no quantity of decimal places repairs it. A dosing interval cannot be reverse-engineered from a half-life even when the half-life is solid, as tesamorelin demonstrates, so it certainly cannot be derived from one that was never measured.
What are the measured half-lives?
Six compounds with a figure traceable to a label or a trial, set beside how often each one is given.
| Compound | Elimination half-life | How often it is given | Interval against half-life | Source |
|---|---|---|---|---|
| Tesamorelin | 11 minutes | Once daily | About 130 half-lives | Egrifta WR label, rev. 3/20252 |
| Liraglutide | About 13 hours | Once daily | Just under 2 half-lives | Saxenda label4 |
| Tirzepatide | About 5 days | Once weekly | About 1.4 half-lives | Mounjaro label, rev. 01/20263 |
| CJC-1295 | 5.8 to 8.1 days, estimated | Weekly or two-weekly in the trial | About 1 to 2 half-lives | Teichman et al., 20068 |
| Semaglutide | About 1 week | Once weekly | About 1 half-life | Wegovy and Ozempic labels, rev. 06/2026 and 5/202615 |
| BPC-157 | No human figure by any route | Not established | Not calculable | FDA briefing document, 11 May 20267 |
Read down the fourth column and the idea that a dosing interval follows from a half-life falls apart. Two drugs given once a day sit at 11 minutes and 13 hours. Two given once a week sit at five days and about seven. Tesamorelin's interval runs to roughly 130 times its half-life while semaglutide's is roughly one.
Figures as of October 11, 2026, taken from the label revisions named in the table. Labels are revised without notice, so the document at the link governs rather than the figure here.
How many timescales does one drug have?
Semaglutide has seven. Every one of them sits in its own labels.
| Question | Figure |
|---|---|
| When does it peak? | 1 to 3 days after the dose15 |
| How fast does it leave the blood? | Elimination half-life about 1 week1 |
| When is it out? | In circulation about 5 weeks (Ozempic) or 5 to 7 weeks (Wegovy)15 |
| How often is it injected? | Once weekly1 |
| How long to reach the maintenance dose? | 16 weeks of escalation1 |
| How long before pregnancy should it stop? | At least 2 months15 |
| How long did the trials run? | Up to 68 weeks1 |
Nothing in that table is in dispute, and no two rows of it answer the same question. The half-life is one row out of seven.
When does the distinction change a decision?
Three situations, and in each of them reaching for the half-life gives the wrong answer.
- Planning a pregnancy. The arithmetic says five weeks and both semaglutide labels say at least two months. Following the shorter figure stops you about a month early.15
- A missed dose. The window each label allows is the thing to check, and it is a tolerability and spacing question instead of a clearance calculation. Our guide on missed GLP-1 doses sets out what each label says.
- Deciding whether something is working. A compound at steady state has reached its plateau, and that tells you nothing about whether the outcome you want has had time to appear. Those timelines differ by months for drugs with trials and are unmeasured for most things sold in a vial.
For anything with no human pharmacokinetic data, all three questions are open, and a confident number is a signal to ask where it came from.
Common questions
What does half-life mean for a peptide?
The time for the amount in your blood to fall by half. A 12-hour half-life means roughly half remains after 12 hours, a quarter after 24 and an eighth after 36. It describes the rate of disappearance from plasma and nothing else.
Is the dosing interval the same as the half-life?
No, and the two can be wildly different. Tesamorelin has an elimination half-life of 11 minutes and is injected once daily, an interval around 130 times its half-life, because it works by triggering a growth hormone pulse that outlasts the molecule. Semaglutide's half-life is about a week and it is injected weekly. Dosing intervals come from trials, not from arithmetic.
What is duration of action, and how is it different from half-life?
Duration of action is how long one dose keeps producing its effect. Half-life is how fast the drug leaves your blood. For a drug that works by occupying a receptor while it is present, the two run close together. For one that works by triggering something else, they can be far apart: tesamorelin clears in minutes and is dosed once a day. A half-life cannot tell you which kind you have.
How many half-lives until a drug is out of your system?
Five half-lives is the usual rule, leaving roughly 3%. It is a reasonable approximation and it is not always what the label says. Semaglutide's five half-lives come to about five weeks, the Wegovy label gives five to seven weeks, and both semaglutide labels ask for at least two months before a planned pregnancy.
How long is semaglutide in your system?
The Ozempic label says semaglutide is present in circulation for about five weeks after the last dose. The Wegovy label says about five to seven weeks after the last injectable dose. Both state an elimination half-life of approximately one week.
How long are peptides detectable in a drug test?
It depends on the assay, the route and the preparation. In one study of five growth hormone releasing peptides given nasally, GHRP-2 and a metabolite were detectable in urine for up to 47 hours, GHRP-6 for up to 23 hours with its metabolites lasting only 12, and GHRP-1 was never detected as the parent compound while one of its metabolites was found for up to 27 hours. The study used one volunteer per peptide, so those hours show that windows vary rather than giving a figure to rely on.
Does kidney or liver disease change the half-life?
For semaglutide the label says it does not meaningfully. Section 12.3 reports no clinically significant differences in semaglutide pharmacokinetics based on renal impairment at an eGFR of 30 to under 90 mL/minute, or on mild, moderate or severe hepatic impairment across Child-Pugh classes A to C. That is specific to semaglutide, and it follows partly from albumin binding keeping clearance away from the kidney. Other compounds differ, and for anything without a human pharmacokinetic study there is no answer at all.
Why does semaglutide last a week when peptides are supposed to break down fast?
Because of a modification added for exactly that purpose. The Wegovy label calls albumin binding "the main protraction mechanism of semaglutide" and states it is more than 99% bound to plasma albumin, giving "decreased renal clearance and protection from degradation". Bound to a large blood protein, the molecule is too big for the kidney to filter and is shielded from the enzymes that would cut it up. Tesamorelin, with no such modification, clears in 11 minutes.
Is bioavailability the same thing as half-life?
No. Bioavailability is the proportion of a dose that reaches the bloodstream unchanged. Half-life is how fast it leaves again. Semaglutide's absolute bioavailability is 89% by injection and about 1% to 2% as an oral tablet, while the half-life is the same either way, so one describes arrival and the other removal.
What is CJC-1295's half-life?
A 2006 trial in healthy adults estimated it at 5.8 to 8.1 days. The same trial found that after one injection growth hormone stayed raised for six days or more and IGF-I for nine to eleven days, so the effect outlasted the drug. Note that sellers list two different compounds under the CJC-1295 name, with and without the modification, and that figure belongs to one of them.
Does semaglutide build up in your system?
Across the early weeks, yes, and that is expected. With a half-life of about a week and a weekly injection, each dose arrives before the previous one has cleared, so levels climb until they settle at a plateau. That is why an unchanged dose does not feel the same in week one as in week six. The CJC-1295 trial recorded the same thing more explicitly, with IGF-I above baseline for up to 28 days after repeated doses and the authors describing a cumulative effect.
Why is there no half-life for retatrutide on this page?
Because no label exists for it and our own half-life index records the circulating figure of about six days as unverified with no stored source. On a page about where half-life numbers come from, quoting an unverified one would be the wrong place to make an exception. If a trial publication or a label appears, it goes in.
Why does the half-life not tell me when it will work?
Because blood levels and outcomes run on different clocks. Semaglutide plateaus in about five weeks, takes 16 weeks of escalation to reach the maintenance dose, and was tested over trials running up to 68 weeks. The drug being at steady state says nothing about whether the result has had time to appear.
What is Tmax?
The time to maximum concentration, meaning how long after a dose the level in blood peaks. Semaglutide reaches it 1 to 3 days after injection. Tirzepatide reaches it 8 to 72 hours after. Tesamorelin reaches it in about nine minutes. Tmax is usually closer to what people mean by "when does it kick in" than the half-life is.
Does BPC-157 have a known half-life?
Not in humans. The FDA's 2026 review states it found no human pharmacokinetic data for BPC-157 after oral, subcutaneous, nasal or transdermal administration. The figure of roughly 8 to 30 minutes that circulates comes from rat studies.
Why do two sources give different half-lives for the same peptide?
Usually because one is human and one is animal, because they measured different routes or doses, or because one is a community figure with no study behind it. Our guide on why two peptide calculators disagree covers how those numbers get into an index and how many have no human source.
Is a longer half-life better?
It is a trade-off rather than an improvement. A longer half-life allows less frequent dosing and makes levels steadier. It also means a side effect takes longer to fade and a washout before pregnancy or surgery runs longer. Semaglutide's one-week half-life is why it is weekly and also why its label asks for two months before conception.
Does the route change the half-life?
It changes the shape of the curve. The elimination half-life is a property of how your body removes the molecule, but the route changes how fast it arrives, how much of it arrives, and therefore what a measured curve looks like. The 2015 detection study found route to be one of three things determining how long its peptides stayed findable.
Sources
- Wegovy (semaglutide injection) prescribing information, revised 06/2026. Novo Nordisk. novo-pi.com/wegovy.pdf. Read at source. Section 12.3: "Maximum concentration of semaglutide is reached 1 to 3 days post dose", elimination half-life "approximately 1 week", and semaglutide is "present in the circulation for about 5 to 7 weeks after the last injectable dose". Section 2: "Administer WEGOVY injection once weekly, on the same day each week", with dose escalation running from week 1 through week 16 and maintenance beginning at week 17. Section 8.3 instructs clinicians to "discontinue WEGOVY in patients at least 2 months before they plan to become pregnant". Section 6.1 describes participants "treated with 2.4 mg WEGOVY injection for up to 68 weeks". Section 11 Description: "The main protraction mechanism of semaglutide is albumin binding." Section 12.3 Distribution: semaglutide "is extensively bound to plasma albumin (greater than 99%)", which "results in decreased renal clearance and protection from degradation". Absorption: "Absolute bioavailability of semaglutide is 89% following subcutaneous administration", and "approximately 1% to 2% following oral tablet administration". Specific Populations: no clinically significant differences in semaglutide pharmacokinetics based on renal impairment at eGFR 30 to under 90 mL/minute, or on mild, moderate and severe hepatic impairment, Child-Pugh Class A to C. Escalation step amounts are in the label and are not reproduced here.
- Egrifta WR (tesamorelin for injection) prescribing information, revised 3/2025. accessdata.fda.gov. Read at source. Section 12.3: "Mean elimination half-life (t1/2) of tesamorelin was 11 minutes in healthy subjects", with a median Tmax of 0.15 hours. Section 2.1: "The recommended dosage of EGRIFTA WR is 1.28 mg subcutaneously once daily." Indicated for the reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy. Cited here for the half-life and the dosing frequency, the comparison this guide makes, and not as guidance on use.
- Mounjaro (tirzepatide injection) prescribing information, revised 01/2026. Eli Lilly, via FDA Drugs@FDA. accessdata.fda.gov. Read at source. Section 12.3: "Following subcutaneous administration, the time to maximum plasma concentration of tirzepatide ranges from 8 to 72 hours", with "an elimination half-life of approximately 5 days".
- Saxenda (liraglutide injection) prescribing information. Novo Nordisk. novo-pi.com/saxenda.pdf. Read at source. Section 12.3 gives "an elimination half-life of approximately 13 hours". Dosed once daily.
- Ozempic (semaglutide injection) prescribing information, revised 5/2026. Novo Nordisk, via DailyMed. dailymed.nlm.nih.gov. Read at source. Section 12.3: "Maximum concentration of semaglutide is reached 1 to 3 days post dose", elimination half-life of approximately 1 week, and semaglutide "will be present in the circulation for about 5 weeks after the last dose". Section 8.3: "Discontinue OZEMPIC in women at least 2 months before a planned pregnancy due to the long washout period for semaglutide."
- Semenistaya E, Zvereva I, Thomas A, Thevis M, Krotov GI, Rodchenkov GM. Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin. Drug Testing and Analysis 2015;7(10):919-925. doi:10.1002/dta.1787. PMID 25869809. Abstract read through the OpenAlex index. That index reconstructs abstract text instead of reproducing it as printed, so the hour figures and which analyte each belongs to should be confirmed against the printed abstract before publishing. As indexed: each compound given nasally to one volunteer, urine collected for two days, analysed by nano-liquid chromatography high resolution mass spectrometry. GHRP-1 parent not detected, its (2-4) free acid metabolite found up to 27 hours; GHRP-2 and its (1-3) free acid up to 47 hours; GHRP-6 mostly excreted unchanged and detected up to 23 hours with metabolites detectable only 12 hours; Hexarelin and Ipamorelin extensively metabolised with no hour figures given in the abstract. Authors conclude the detection window depends on individual metabolism, the drug preparation form and the route of administration. Single-subject data per compound and a nasal route, so cited as evidence that windows vary rather than as reference values.
- FDA Briefing Document, Pharmacy Compounding Advisory Committee meeting of 23-24 July 2026, memo dated 11 May 2026. US Food and Drug Administration. fda.gov/media/193343/download. Read at source. States that FDA "found no human pharmacokinetic data for BPC-157 after oral, SC, nasal, or transdermal" administration. Also notes BPC-157 was "reported to be resistant to hydrolysis in gastric juice in vitro" and that "it does not appear that BPC-157 is absorbed systemically when given as a rectal enema". The 8 to 30 minute figure in circulation for BPC-157 is from rodent work and is described as such here; no human figure is quoted.
- Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. The Journal of Clinical Endocrinology & Metabolism 2006;91(3):799-805. doi:10.1210/jc.2005-1536. PMID 16352683. Abstract read through the OpenAlex index, which reconstructs abstract text rather than reproducing it as printed, so the figures should be confirmed against the printed abstract before publishing. As indexed: two randomised, placebo-controlled, double-blind ascending-dose trials of 28 and 49 days in healthy subjects aged 21 to 61, given CJC-1295 or placebo subcutaneously. Estimated half-life of CJC-1295 of 5.8 to 8.1 days. After a single injection, plasma GH rose 2- to 10-fold for 6 days or more and plasma IGF-I rose 1.5- to 3-fold for 9 to 11 days; after multiple doses mean IGF-I remained above baseline for up to 28 days, with the authors describing evidence of a cumulative effect. Context states that therapeutic use of GHRH "is limited by its short duration of action". The enrolled subject count and the four single-dose levels are not given in the indexed abstract, and no albumin-binding or other protraction mechanism is described in it, so none is asserted on this page. Doses are not reproduced here beyond the paper's note that 30 and 60 micrograms per kilogram were relatively well tolerated, which is reported as a trial finding and not as guidance.
Citing this page. Peptide Decoding. What Is a Peptide Half-Life? Why It Differs From How Long It Works. Pharmacokinetic figures from the Wegovy, Ozempic, Mounjaro, Saxenda and Egrifta WR labels; detection figures from Drug Testing and Analysis 2015; BPC-157 pharmacokinetic status from the FDA briefing document of May 11, 2026. https://peptidedecoding.com/guides/peptide-half-life