"BPC-157 half-life" is searched because the dosing schedules in circulation, once or twice a day, raise the question of how long the peptide lasts. The answer exists in exactly one place: a 2022 study in rats and beagle dogs that measured the peptide in plasma after intravenous and intramuscular doses. No human figure has been published. This page sets out what that study measured, what it did not, and what the numbers mean in arithmetic, from its full text read on 2026-10-28. It reports; it recommends no schedule.
Half-lives for the other compounds on this site, each beside the schedule its label or trials used, are on peptide dosing frequency; the reported doses are on the BPC-157 dosage page.
What the study measured
He and colleagues gave BPC-157 to six animals per group: rats at 20 µg/kg intravenously and 20, 100 or 500 µg/kg intramuscularly; dogs at 6 µg/kg intravenously and 6, 30 or 150 µg/kg intramuscularly; plus seven daily intramuscular doses in each species. The rat and dog doses were chosen as body-surface-area equivalents of a "proposed clinical dose" of 200 µg per person per day, the authors' own figure.
| Species · route · dose | Peak time | Half-life | Bioavailability |
|---|---|---|---|
| Rat · IV · 20 µg/kg | — | 15.2 min | (reference) |
| Rat · IM · 20 µg/kg | 3 min | 7.87 min | 18.8% |
| Rat · IM · 100 µg/kg | 3 min | 17.1 min | 14.5% |
| Rat · IM · 500 µg/kg | 3 min | 29.7 min | 19.4% |
| Rat · IM · 100 µg/kg daily × 7 | 3 min | 18.5 min | — |
| Dog · IV · 6 µg/kg | — | 5.27 min | (reference) |
| Dog · IM · 6 µg/kg | 6.3 min | 20.0 min | 45.3% |
| Dog · IM · 30 µg/kg | 8.7 min | 25.5 min | 47.6% |
| Dog · IM · 150 µg/kg | 8.2 min | 29.3 min | 50.6% |
Means from the paper's Tables 1–6. One discrepancy in the paper: the title of Table 2 says "doses ranging between 5 and 120 μg/kg", while its rows and the methods give 20, 100 and 500; this page uses the rows.
What happens after the peak
The peptide reached its peak within minutes and was gone from plasma within hours: the authors state that the unchanged drug "could not be detected 4 h after administration". With tritium-labelled peptide they followed where it went. Radioactivity peaked in most tissues at one hour, highest in the kidney, followed by the liver, stomach wall, spleen and thymus, and was excreted mainly in urine and bile. The labelled peptide was "rapidly metabolized into a variety of small peptide fragments" and then single amino acids. Radioactivity in a tissue at 24 hours therefore tracks the label, which can sit in ordinary amino acids, not intact BPC-157.
The seven-day arm matters for the schedule question. After a week of daily 100 µg/kg doses in rats the half-life was 18.5 minutes, as after one dose, and the trough concentration before each dose was zero: nothing carried over from one day to the next.
The arithmetic of a short half-life
| Half-life | Half-lives in 4 h | Left after 4 h | Half-lives in 24 h |
|---|---|---|---|
| 5.3 min (dog, IV) | 45 | ≈0 | 273 |
| 15.2 min (rat, IV) | 16 | 0.002% | 95 |
| 30 min (upper bound, IM) | 8 | 0.39% | 48 |
Fraction left = 0.5 raised to the number of half-lives elapsed. A once-daily dose at any of these values leaves plasma empty for most of the day, which is consistent with the zero trough the study measured. The BPC-157 vial arithmetic converts the amounts in circulation into syringe units.
Why the half-life does not settle the schedule
Several animal studies of BPC-157 report effects from once-daily or even single doses, and the 2022 authors describe it as effective "at very low doses". A half-life of minutes alongside an effect over days means the effect, if it holds, does not depend on the peptide staying in the blood, the same pattern the tesamorelin labels show for a releasing hormone. No study, animal or human, has compared dosing intervals for BPC-157 against an outcome, so neither "once a day" nor "twice a day" rests on a pharmacokinetic finding. The route question is covered on oral vs injected BPC-157.
What is not established
Any human half-life: none published; the one registered human trial (NCT02637284, oral tablets, 2015) has posted nothing in ten years. Oral or subcutaneous pharmacokinetics in any species: the 2022 study tested intravenous and intramuscular dosing only. Whether the rat or dog figures scale to people: not tested. Medibact's BPC-157 guide covers the compound. Decisions about whether to use it belong with a clinician.