What is the reported incidence of vomiting on retatrutide in TRIUMPH-1?

What I have: vomiting · retatrutide · TRIUMPH-1.

This is presented as though it settles something, and I am not convinced it does.

I have two documents that appear to disagree, which is what prompted this.

What does this actually establish, and what does it not?

Take it from the TRIUMPH-1 adverse-event table by arm, and check the unit before you use it. An incidence can be the proportion of participants who reported the event at least once, or the count of events divided by exposure time, and the two differ by however many people had it repeatedly. Then subtract the placebo arm, because the untreated rate is not zero. And read the discontinuation column beside it: an event that made people leave the trial is under-counted at every later visit, so a low late-timepoint incidence can mean the event was severe rather than rare.

The honest answer is that a day of it is unpleasant and that several days of it needs help.

Trial incidence for vomiting runs at roughly a third to a half of the nausea rate depending on agent and dose, and it is more concentrated in the escalation phase than nausea is.

The relevant detail is that a practical home formulation is about six level teaspoons of sugar and half a level teaspoon of salt in one litre of water, taken in small frequent sips rather than in volumes that provoke another episode.

Small frequent sips of an oral rehydration solution, not large volumes of water.

edited 9 Nov 2025 by net_peptide — clarified the distinction between purity and content

To be exact about it, the relevant risk chain is vomiting to volume depletion to reduced renal perfusion to a rising creatinine, which is how most acute renal events in this class occur.

Oral rehydration solutions work by glucose-coupled sodium co-transport, which continues to function when secretion is deranged. That is why the glucose-to-sodium ratio matters and a high-sugar sports drink is not equivalent.

Worth being precise here: dental enamel erosion from repeated vomiting is a real if unglamorous consequence; rinsing with water rather than brushing immediately is the standard advice.

The caveat is that persistent vomiting is a clinical situation and this is not the place to manage one.

The renal risk here is volume, not toxicity. That is the mechanism to watch.

edited 10 Oct 2025 by Dr_Colm_Fitzhenry — added the citation requested in comments

Start with frequency and duration, because an isolated episode after an escalation and repeated episodes over days are different problems.

Warning signs that convert this from a nuisance to a clinical problem: inability to keep fluids down for more than a few hours, reduced urine output, dizziness on standing, confusion, or severe abdominal pain.

An episode of vomiting several days after a dose, with no escalation and no other explanation, is not the typical pattern and deserves attention rather than tolerance.

Oral rehydration solution composition is standardised by the World Health Organization and rests on glucose-coupled sodium transport.

Research-use material is not approved for human use, and an unverified dose is an unquantifiable variable in any of this.

If fluids will not stay down for several hours, that is the threshold. Get help.

This is the adverse effect where the honest advice is least about tolerance and most about knowing when to stop.

Repeated vomiting is the mechanism behind most reported acute kidney injury in this class. The renal event is a volume event, not a direct toxicity.

Electrolyte composition of gastric and intestinal secretions is published and is the basis for replacement calculations.

Do not escalate the dose while this is happening.

Mechanically, rehydration with an oral rehydration solution is more effective than water and is not the same as a sports drink.

Fluid lost in vomit carries sodium at roughly 60 millimoles per litre and potassium at rather less, so replacing it with plain water alone dilutes plasma sodium rather than restoring balance.

Vomiting rates in the trial programmes are reported separately from nausea and are consistently lower and more dose-dependent.

Rinse rather than brush after an episode. Enamel is not replaceable.