Half-life reference / Library model input
PT-141 half-life
The PinPoint library stores 2.5 hours (0.1042 days) for PT-141. This is the input behind the arithmetic below, not a measurement of your levels or how long an effect lasts.
DailyMed bremelanotide prescribing information: terminal half-life approximately 2.7 hours; the library stores 2.5 hours.
Library snapshot, 2026-10-05: CompoundLibrary.swift:703, halfLifeHours: 2.5. Read the cited reference.
Reading this particular reference
PT-141 has a small but material source mismatch: the stored input is 2.5 hours and the library citation describes approximately 2.7 hours. This page preserves the stored value for reproducible arithmetic and states the difference rather than silently replacing it. The frequency list includes as-needed use and a once-in-24-hours limit label. An irregular history has no single fixed interval, so an accumulation ratio is intentionally not assigned.
The source note reports approximately 2.7 hours, distinct from the stored 2.5-hour model input. The library lists subcutaneous for tracking. A listed route is not proof that every input was measured through that route. The linked reference and its study context matter when interpreting the stored number.
PT-141 decay table
Starting at an arbitrary 100%, each elapsed half-life divides the remaining modeled amount by two. The calculation is 100 × 2 raised to the power of minus elapsed hours divided by 2.5. It describes a single contribution with no additional entries. The percentages are not percentages of benefit, receptor activity, or symptom relief.
| Half-lives | Hours | Days | Remaining (rounded) |
|---|---|---|---|
| 0 | 0 | 0 | 100.0% |
| 1 | 2.5 | 0.1042 | 50.0% |
| 2 | 5 | 0.2083 | 25.0% |
| 3 | 7.5 | 0.3125 | 12.5% |
| 4 | 10 | 0.4167 | 6.3% |
What the listed schedules mean mathematically
The library labels are As needed; Not more than once in 24h. They describe available tracking patterns, not instructions. In an equal-input model, the limiting peak accumulation ratio is 1 ÷ (1 − 2 raised to minus interval divided by half-life). It compares a repeated pattern with one instantaneous input and assumes the same interval continues indefinitely.
- As needed: no unique fixed interval is specified, so no accumulation ratio is assigned.
- Not more than once in 24h: no unique fixed interval is specified, so no accumulation ratio is assigned.
From a reference curve to a dose history
PinPoint’s Home curve models your levels between doses from published half-life data. Drag to scrub modeled values at any timestamp, or preview 30 days of a dose pattern. Log injections with compound, dose, site, and pain level, and backfill past doses so the history is complete from day one.
The graph on this page is simpler: it isolates exponential elimination so you can inspect the arithmetic. PinPoint’s modeled curves are mathematical visualizations of published population averages and do not account for individual variation. A modeled amount is not a laboratory concentration.
Explore dose logging in PinPoint or compare library half-life inputs.
Questions, answered
Is the half-life of PT-141 the same for everyone?
No. Half-life varies with the person, formulation and study context. The source note reports approximately 2.7 hours, distinct from the stored 2.5-hour model input. The stored number is a reference input, not a personal measurement.
How long until PT-141 clears?
With the stored 2.5-hour scalar, five half-lives take 12.5 hours (0.5208 days), leaving 3.125% of one modeled starting contribution. Exponential decay never reaches exactly zero. This is not a detection window, a washout instruction, or proof that effects have ended.
PinPoint is a tracking and unit-conversion tool, not a medical device. Modeled levels are mathematical illustrations, not blood tests or individual predictions. Medical decisions belong with your healthcare provider.