Reference schedules
Retatrutide and Tirzepatide titration schedules
These tables summarise the step-up patterns used in published research protocols for each compound. They are provided as laboratory reference material only — nothing here is a recommendation for human use.
Retatrutide 20mg pen
£220 + postage| Stage | Weekly amount | Notes |
|---|---|---|
| Weeks 1–4 | 2 mg | Introductory phase — lowest research increment |
| Weeks 5–8 | 4 mg | First step up, only if week 4 was well tolerated |
| Weeks 9–12 | 6 mg | Mid-range research window |
| Weeks 13–16 | 8 mg | Upper-mid range, hold longer before stepping again |
| Weeks 17+ | 10–12 mg | Top of the studied range in Phase 2 protocols |
Tirzepatide pen
£185 + postage| Stage | Weekly amount | Notes |
|---|---|---|
| Weeks 1–4 | 2.5 mg | Starting increment used across trial protocols |
| Weeks 5–8 | 5 mg | First maintenance level |
| Weeks 9–12 | 7.5 mg | Step up only after four steady weeks |
| Weeks 13–16 | 10 mg | Common upper maintenance level |
| Weeks 17+ | 12.5–15 mg | Maximum studied range |
Reading the pen dial
Pens are dialled in units, not milligrams. Divide the cartridge strength by its volume to get the concentration, then work out the units for the amount you need.
| Cartridge | Concentration | 2 mg equals | Doses per cartridge |
|---|---|---|---|
| 20 mg in 2 ml | 10 mg / ml | 0.2 ml (20 units) | 10 × 2 mg steps |
| 10 mg in 1 ml | 10 mg / ml | 0.2 ml (20 units) | 5 × 2 mg steps |
Schedule handling notes
- → One administration per week, same day each week where possible
- → Hold each step for a full four weeks before stepping up
- → Step back down a level rather than skipping a week if tolerance drops
- → Bring the pen to room temperature and prime before every use
- → Fresh needle each time; rotate sites; sharps bin for disposal
- → Return the pen to 2–8°C storage between sessions
Need the printed version? The 20mg pen guide (PDF) covers the same schedule alongside specs, pathways and storage.
Supplied strictly for laboratory research purposes. Not for human or veterinary consumption. No information on this page is medical advice.