The case in front of me: dizziness · five · liraglutide.
I can find plenty of assertions about this and almost no reasoning, which is usually a sign that nobody has checked.
Assume no laboratory access beyond what I can pay a third party for.
Which parts of this are load-bearing and which parts are habit?
Week 5 is day 35: on a four-week ladder that is week 1 of dose step 2, and — at the seven-day half-life this class runs on — 5 half-lives in. Steady state is about five half-lives, so day 35 is where the concentration stops climbing on its own. Day 35 is exactly that point. That distinction is most of the question: at week 1 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. Dizziness in a deficit is usually postural and usually volume-related. It is also the symptom on this list with the shortest path to something that needs assessing in person rather than posting about. Dose decisions are made under supervision, and nothing here is medical advice.
The honest answer is that going slower costs time and nothing else, since the exposure ceiling is unchanged.
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.
| Week | Fraction of steady state | Trough as × dose |
|---|---|---|
| 1 | 50 % | 0.50 |
| 2 | 75 % | 0.75 |
| 3 | 88 % | 0.88 |
| 4 | 94 % | 0.94 |
| 5 | 97 % | 0.97 |
| 6 | 98 % | 0.98 |
This is why a four-week step interval is approximately, but not exactly, steady state.
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.
Titration schedules in the licensed products were designed specifically to manage gastrointestinal tolerability, and that intent is stated in the clinical development literature.
Faster titration does not reach the destination sooner in any way that matters; it reaches the symptoms sooner.
Stepping back is a normal adjustment, not a failure.
HPLC purity, identity confirmation and quantified content on the vial you actually hold. Reports arrive with the chromatogram attached, not just a number.
Submit a sampleFounded 1998. ISO 9001 and cGMP certified, 1,500+ staff and 200+ patents. The synthesis house behind a great many of the vials that get sent out for testing - batch-specific documentation with every order.
Visit GL BiochemThe short version: four-weekly steps for the weekly agents, hold rather than escalate when symptoms are active, and slower is always available.
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.
Concretely, titrating downward is available too. Stepping back and holding is a normal adjustment rather than a failure.
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.
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.
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.
Slower costs time and nothing else. The ceiling is the same.
The part that matters: the initiation step in most schedules is not intended to be therapeutic; it is there to introduce the receptor to the drug.
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.
A schedule described here is a published schedule for a licensed product and is not a recommendation.
The top of the schedule is not the target. The working dose is.
edited 4 Sept 2025 by dmitri_savchuk — tightened the wording; no substantive change
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.
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.
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.