Schedule A
2 mg Every 7 days
Δ Delta
1.92×
Week 6 · Day 01.342 mg eq.+0.0 d after dose
- Peak
- 2.60 mg eq.
- Trough
- 1.35 mg eq.
- Average
- 2.00 mg eq.
- Spread
- 1.25 mg eq.
- 95% steady state
- By day 21(shot 4)
GLP-1 Plotter
Compare how dose and interval change the weekly level and 12-week accumulation curve.
Schedule A
Schedule B
Modeled level in mg eq.
Week 6 · Day 0
Schedule A1.342 mg eq.+0.0 d after dose
Schedule B2.038 mg eq.+0.0 d after dose
Schedule B
1 mg Every 3 days
Δ Delta
1.21×
Week 6 · Day 02.038 mg eq.+0.0 d after dose
- Peak
- 2.50 mg eq.
- Trough
- 2.06 mg eq.
- Average
- 2.33 mg eq.
- Spread
- 0.44 mg eq.
- 95% steady state
- By day 27(shot 10)
How to Read the PK View
Retatrutide enters the bloodstream gradually. Phase I clinical studies found that retatrutide reached peak concentration 12-72 hours after dosing. The concentration curves observed in the clinical data show slower accumulation at low doses, while the higher-dose curves cluster roughly around 24h. This model follows that measured change: dose changes the peak and reshapes the curve.1, 2
By carrying absorption, distribution, and clearance through time, this view gives a more faithful curve for comparing Retatrutide doses and intervals than a simple half-life calculation. The result is rescaled to milligram equivalents (mg eq.), allowing the two schedules to remain directly comparable. Mg eq. is a modeled display scale rather than a laboratory concentration and applies only within the selected compound.
Retatrutide Injection Table
Schedule A
2 mg every 7 days
Δ Delta1.92×
| Shot | Injection day | Peakmg eq. | Troughmg eq. | Steady statepeak reached |
|---|---|---|---|---|
| 01 | Day 0 | 1.39 | 0.74 | 53% |
| 02 | Day 7 | 2.05 | 1.08 | 79% |
| 03 | Day 14 | 2.35 | 1.23 | 90% |
| 04 | Day 21 | 2.49 | 1.30 | 96% |
| 05 | Day 28 | 2.55 | 1.33 | 98% |
| 06 | Day 35 | 2.58 | 1.34 | 99% |
| 07 | Day 42 | 2.59 | 1.35 | 100% |
| 08 | Day 49 | 2.60 | 1.35 | 100% |
| 09 | Day 56 | 2.60 | 1.35 | 100% |
| 10 | Day 63 | 2.60 | 1.35 | 100% |
| 11 | Day 70 | 2.60 | 1.35 | 100% |
| 12 | Day 77 | 2.60 | 1.35 | 100% |
Schedule B
1 mg every 3 days
Δ Delta1.21×
| Shot | Injection day | Peakmg eq. | Troughmg eq. | Steady statepeak reached |
|---|---|---|---|---|
| 01 | Day 0 | 0.66 | 0.59 | 27% |
| 02 | Day 3 | 1.15 | 1.01 | 46% |
| 03 | Day 6 | 1.53 | 1.31 | 61% |
| 04 | Day 9 | 1.80 | 1.53 | 72% |
| 05 | Day 12 | 2.00 | 1.68 | 80% |
| 06 | Day 15 | 2.14 | 1.79 | 86% |
| 07 | Day 18 | 2.24 | 1.87 | 90% |
| 08 | Day 21 | 2.32 | 1.92 | 93% |
| 09 | Day 24 | 2.37 | 1.96 | 95% |
| 10 | Day 27 | 2.41 | 1.99 | 96% |
| 11 | Day 30 | 2.43 | 2.01 | 97% |
| 12 | Day 33 | 2.45 | 2.02 | 98% |
| Schedule A2 mg every 7 days | Schedule B1 mg every 3 days | |
|---|---|---|
| Shot | 01 · Day 0 | 01 · Day 0 |
| Peak | 1.39 | 0.66 |
| Trough | 0.74 | 0.59 |
| Steady state | 53% | 27% |
| Shot | 02 · Day 7 | 02 · Day 3 |
| Peak | 2.05 | 1.15 |
| Trough | 1.08 | 1.01 |
| Steady state | 79% | 46% |
| Shot | 03 · Day 14 | 03 · Day 6 |
| Peak | 2.35 | 1.53 |
| Trough | 1.23 | 1.31 |
| Steady state | 90% | 61% |
| Shot | 04 · Day 21 | 04 · Day 9 |
| Peak | 2.49 | 1.80 |
| Trough | 1.30 | 1.53 |
| Steady state | 96% | 72% |
| Shot | 05 · Day 28 | 05 · Day 12 |
| Peak | 2.55 | 2.00 |
| Trough | 1.33 | 1.68 |
| Steady state | 98% | 80% |
| Shot | 06 · Day 35 | 06 · Day 15 |
| Peak | 2.58 | 2.14 |
| Trough | 1.34 | 1.79 |
| Steady state | 99% | 86% |
| Shot | 07 · Day 42 | 07 · Day 18 |
| Peak | 2.59 | 2.24 |
| Trough | 1.35 | 1.87 |
| Steady state | 100% | 90% |
| Shot | 08 · Day 49 | 08 · Day 21 |
| Peak | 2.60 | 2.32 |
| Trough | 1.35 | 1.92 |
| Steady state | 100% | 93% |
| Shot | 09 · Day 56 | 09 · Day 24 |
| Peak | 2.60 | 2.37 |
| Trough | 1.35 | 1.96 |
| Steady state | 100% | 95% |
| Shot | 10 · Day 63 | 10 · Day 27 |
| Peak | 2.60 | 2.41 |
| Trough | 1.35 | 1.99 |
| Steady state | 100% | 96% |
| Shot | 11 · Day 70 | 11 · Day 30 |
| Peak | 2.60 | 2.43 |
| Trough | 1.35 | 2.01 |
| Steady state | 100% | 97% |
| Shot | 12 · Day 77 | 12 · Day 33 |
| Peak | 2.60 | 2.45 |
| Trough | 1.35 | 2.02 |
| Steady state | 100% | 98% |
Method
PK calculation
Retatrutide uses three peak-normalized response curves built from Phase 1's 0.1-0.3 mg, 1 mg, and 3-6 mg data and Phase 1b's 3-6 mg data. The model follows each measured ascent through its peak, anchoring higher-dose curves at approximately 24 hours, then applies the shared 6.12-day elimination phase. Each curve carries the same exposure per milligram and blends continuously into the next.1, 2
How the summaries are calculated
The cards use a repeating steady-state interval. Peak is the highest modeled value between injections, trough is the value just before the next injection, and average is the interval average. Δ Delta is peak divided by trough. By day X (shot Y) identifies the first injection whose peak reaches 95% of the repeating steady-state peak and its normalized day from the first injection. The table starts at the first injection and shows finite accumulation through shot 12.
What mg eq. means
The PK equations produce a model level, not milligrams. The page uses one fixed display anchor: 4 mg every 7 days. The average modeled level at that reference is set to 4 mg eq. This keeps schedules for one compound comparable without presenting the result as a blood concentration.
Scope and limits
Retatrutide reached peak concentration 12-72 hours after dosing across the Phase I clinical data. This model uses Coskun's full single-dose concentration curves and Urva's repeated-dose data to represent the slower low-dose ascent and roughly one-day higher-dose peak. Subsequent retatrutide studies in The Lancet (Rosenstock et al., 2023), The New England Journal of Medicine (Jastreboff et al., 2023), and Nature Medicine (Sanyal et al., 2024) use those Phase I studies as their pharmacokinetic foundation.
Retatrutide References
- Coskun T, Urva S, Roell WC, et al. LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: From discovery to clinical proof of concept. Cell Metabolism. 2022;34:1234-1247.
- Urva S, Coskun T, Loh MT, et al. LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial. The Lancet. 2022;400:1869-1881.
