6 posts
Dose logging
Injections, titration, site rotation, half-life curves and schedules.
- What should you log with every GLP-1 dose? Nine fieldsNine typed fields: time, medication, milligrams, route, site, vial, taken, pain and colour. What each one lets you answer later, and why there is no notes box.
- How long until a GLP-1 reaches steady state? Four to five half-livesFour to five half-lives — 28–35 days for semaglutide, 24–30 for retatrutide, 20–25 for tirzepatide. Why weekly doses stack, and what 'in your system' counts.
- How to chart a titration, and why the scale lags a dose stepPeptrend colours each segment of the weight line by the dose behind it, so a 1.2 to 3.5 mg ladder reads as a four-colour ramp. Why a step takes weeks to land.
- Injection site rotation: how to keep track without a body mapRotation works when the order is decided in advance. Peptrend saves a site with every dose and suggests the next by round-robin through your list — no body map.
- When does a GLP-1 peak after injection? Tmax and the absorption curveHours to days after the shot — 1 to 3 days for semaglutide, 8 to 72 hours for tirzepatide by the labels. The peak lands at D × F × 2^(−Tmax ÷ half-life).
- Does oral semaglutide have the same half-life as the injection?About a week either way. The interval is what differs: a daily tablet ripples by about 10%, while a weekly injection swings by a factor of two.