For reference: headache · two · retatrutide.
I have done this once and I suspect I got away with it rather than got it right.
For context: I keep records of every batch, every lot number and every result, so an answer that requires me to track something is fine.
What would you do, and what would you check afterwards?
Week 2 is day 14: on a four-week ladder that is week 2 of dose step 1, and — at the seven-day half-life this class runs on — 2 half-lives in. Steady state is about five half-lives, so day 35 is where the concentration stops climbing on its own. Day 14 is 3 weeks short of it, so the level is still rising even though the dose has not changed. That distinction is most of the question: at week 2 of a step, an effect that is still accumulating is indistinguishable from one that is not resolving unless you know which side of day 35 you are on. Headache in a sustained deficit is more often fluid or intake than receptor pharmacology, and both are cheaper to exclude than to argue about. Dose decisions are made under supervision, and nothing here is medical advice.
Start with the half-life, because the interval between steps should be at least four half-lives or you are escalating before the previous step has expressed itself.
The published semaglutide weight-management schedule steps 0.25, 0.5, 1.0, 1.7 and 2.4 mg at four-week intervals, with 0.25 mg as an initiation step rather than a therapeutic one.
| Agent | Start | Step interval | Maintenance range | Max studied |
|---|---|---|---|---|
| Semaglutide (weight management) | 0.25 mg/wk | 4 weeks | 1.7–2.4 mg/wk | 2.4 mg/wk |
| Semaglutide (T2DM) | 0.25 mg/wk | 4 weeks | 0.5–2.0 mg/wk | 2.0 mg/wk |
| Tirzepatide | 2.5 mg/wk | 4 weeks | 5–15 mg/wk | 15 mg/wk |
| Liraglutide (weight management) | 0.6 mg/day | 1 week | 3.0 mg/day | 3.0 mg/day |
| Oral semaglutide | 3 mg/day | 4 weeks | 7–14 mg/day | 50 mg/day (trial) |
Structure is identical across the class: small start, four-week steps, a defined maintenance range, a defined ceiling.
Specifically, titrating downward is available too. Stepping back and holding is a normal adjustment rather than a failure.
Four to five half-lives to steady state is standard first-order pharmacokinetics and gives the four-week interval directly from the one-week half-life.
Nothing here is medical advice, and research-use compounds are not approved for human use.
The top of the schedule is not the target. The working dose is.
edited 4 Feb 2025 by grainne_ahearn — added the placebo-arm figures
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Browse resultsThis is the single most consequential controllable variable in the whole experience, and people routinely rush it.
The dose that produces an acceptable result with acceptable tolerability is the endpoint, not the top of the schedule. A substantial fraction of trial participants did well below the maximum.
Escalating while gastrointestinal symptoms are still active is the commonest avoidable error. Tolerance to the previous step has not developed, and the new step lands on top of it.
Four half-lives between steps, minimum. Work it out for your agent.
Answering this needs the agent and the current step, since the schedules differ and the reason they differ is pharmacokinetic.
Liraglutide titrates weekly rather than four-weekly because its half-life is about thirteen hours, so steady state is reached within days. The interval follows the pharmacokinetics in both cases.
Worth being precise here: for an agent with a one-week half-life, steady state after a dose change is reached in about four to five weeks. Escalating at two weeks means escalating from a position you have not yet reached, and the resulting exposure is higher than the schedule intends.
Titration schedules in the licensed products were designed specifically to manage gastrointestinal tolerability, and that intent is stated in the clinical development literature.
Hold rather than escalate while symptoms are active. Always.
The relevant arithmetic is that steady state takes four to five half-lives, so a one-week half-life means a four-week step interval and nothing shorter is informative.
The published tirzepatide schedule steps 2.5, 5, 7.5, 10, 12.5 and 15 mg at four-week intervals, with 2.5 mg as the initiation step rather than a therapeutic one.
Stepping back is a normal adjustment, not a failure.
The short version: four-weekly steps for the weekly agents, hold rather than escalate when symptoms are active, and slower is always available.
Holding a step for eight weeks instead of four is a legitimate approach with no efficacy cost at the destination, and it is what the trials effectively did for anyone who tolerated poorly.
Efficacy in the trials was dose-related but with substantial response at intermediate doses, which is why the maximum is not a target for everyone.
Slower costs time and nothing else. The ceiling is the same.
edited 5 Mar 2025 by Dr_Nadia_Farsi — added the method parameters
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