Vomiting on Foundayo™

Six times the placebo rate at the top dose

Foundayo™ is a once-daily tablet of orforglipron, a GLP-1 receptor agonist that the US label approves for weight management in adults; the US label does not cover type 2 diabetes ^[1]. Table 1 of section 6.1 pools Trials 1 and 2, the 72-week ATTAIN-1 and ATTAIN-2 studies, in which adults with obesity or overweight, some with type 2 diabetes, took the tablet or placebo ^[1]. Vomiting was the fourth most common reaction. On placebo it was uncommon, so the gap with treatment is wide in relative terms.

The Medication Guide lists vomiting among the most common side effects ^[2]. In Europe, the medicines committee adopted a positive opinion on 15 October 2026 and named nausea, vomiting and diarrhea as the most common side effects, but there is no EMA product information yet and so no EU frequency band ^[3]. Health Canada’s drug database has no Foundayo™ or orforglipron entry ^[4].

Steeper than nausea

Nausea in the same table almost levelled off above 9 mg, at 34% and then 35% ^[1]. Vomiting kept rising: 13%, then 21%, then 24%. Between 5.5 mg and 17.2 mg it gained 11 percentage points, more than any other row in Table 1 ^[1]. Queasiness without vomiting is covered on the Foundayo™ nausea page.

When the label describes timing, it groups vomiting with nausea and diarrhea: all three were more common during dose escalation and became less frequent later ^[1]. Of the people who had any stomach reaction, 60% rated it mild, 36% moderate and 4% severe, and severe stomach reactions as a whole were reported by about 3% on orforglipron against 1% on placebo (sections 5.3 and 6.1) ^[1].

What each trial registry recorded

The label pools its trials, but each study also posted results on ClinicalTrials.gov. The ATTAIN registries list non-serious events seen in at least 5% of a group plus every serious event; ACHIEVE-5 and ACHIEVE-J list every event ^[5][6][7][8]. The ACHIEVE studies enrolled people with type 2 diabetes and used their own trial doses.

Reading the registry rows

• In the two ATTAIN trials, the 6, 12 and 36 mg trial doses correspond to Foundayo™ 5.5, 9 and 17.2 mg, and each trial on its own climbs the way the pooled label table does ^[1][5][6].
• Vomiting logged as a serious adverse event was rare: one person in each of three trials, all on the 12 mg or 36 mg trial dose, and none on placebo ^[5][6][7].
• ACHIEVE-J had no dose gradient: roughly one person in eight vomited on each dose ^[8]. It was open label, had no placebo group and enrolled only Japanese adults with type 2 diabetes, so one flat result does not overturn the pattern from the double-blind trials.
• The published ATTAIN-2 trial describes stomach events as mostly mild to moderate and concentrated in escalation ^[9]; in ATTAIN-1, 5.3% to 10.3% on orforglipron stopped because of adverse events, against 2.7% on placebo ^[10]. Neither abstract gives a vomiting figure.

Why vomiting follows the dose

Supported by the label: Foundayo™ slows stomach emptying, and section 12.2 says the delay is largest after the first dose and shrinks over time ^[1]. The label starts low and raises the dose in steps at least 30 days apart specifically to reduce stomach reactions (section 2.1), and its timing statement fits: vomiting was more frequent during escalation ^[1].

Plausible but not measured: section 7.1 says strong CYP3A4 inhibitors, a group of medicines that slow how the liver clears orforglipron, raise its levels and may increase the risk of its adverse reactions, which is why the label caps the dose with them ^[1]. The label does not report vomiting rates in people taking such medicines, so how much this matters for vomiting is unknown.

General medical knowledge: MedlinePlus lists medicines among the many causes of nausea and vomiting ^[11]. After a dose step the tablet is a fair first suspect, but only one of several.

When the cause may be something else

MedlinePlus lists many reasons to vomit that have nothing to do with a weight medicine ^[11]. In ATTAIN-1, gastroenteritis was itself recorded in 5.7% to 6.9% of people on orforglipron and 3.8% on placebo ^[5], a reminder that a stomach bug and the tablet can overlap.

• A stomach or intestinal infection, or food poisoning ^[11].
• Migraine and motion sickness ^[11].
• Reflux disease and ulcers ^[11].
• A blocked bowel; GLP-1 medicines as a class have post-marketing reports of ileus and intestinal obstruction (section 6.2) ^[1][11].
• Pregnancy; the label says Foundayo™ is stopped once a pregnancy is recognised (section 8.1) ^[1][11].
• Other medicines, including cancer chemotherapy ^[11].

Fluids, the kidneys and the signs of running dry

Section 5.4 describes acute kidney injury, sometimes needing dialysis, in people on GLP-1 receptor agonists or Foundayo™; most reported cases followed nausea, vomiting or diarrhea that had left people dehydrated ^[1]. In the pooled trials it was reported in 0.2% on Foundayo™ against 0.05% on placebo ^[1]. Prescribers are asked to check kidney function when such reactions occur, especially around dose steps, and patients to guard against fluid loss and report persistent vomiting (section 17) ^[1]. The Medication Guide stresses drinking fluids as a way to lower the chance of dehydration ^[2].

MedlinePlus describes the earlier signs of dehydration as thirst, a dry or sticky mouth, passing little urine that is darker than usual, dry cool skin, headache and muscle cramps. Severe dehydration can mean passing no urine at all, confusion, dizziness, a racing heart, fast breathing and sunken eyes ^[12].

What the sources suggest on a vomiting day

MedlinePlus puts fluids first; if liquids keep coming back, it suggests small amounts of clear liquid taken often. It also suggests bland food, avoiding spicy, fatty or salty dishes, eating smaller meals more often and staying away from strong smells ^[11]. For milder dehydration, its encyclopedia suggests sipping water, sucking ice cubes, or drinking water or sports drinks that contain electrolytes, and it warns against salt tablets ^[12].

MedlinePlus also notes that some medicines treat nausea and vomiting ^[11]. Because Foundayo™ slows stomach emptying and can change how other tablets are absorbed (section 7.3) ^[1], ask a pharmacist before adding any anti-sickness medicine. Any change to the dose plan is your prescriber’s call; the label ties escalation to how well each step is tolerated ^[1].

A tablet that came back up, and your other tablets

The prescribing information gives no instruction for a tablet vomited soon after it was swallowed ^[1]. Its missed-dose rule is to take the tablet as soon as possible without doubling the next one, and after seven or more missed days in a row escalation restarts at a lower dose (section 2.3) ^[1]. The Medication Guide adds that no more than one tablet is taken in a day and that two doses never fall on the same day ^[2]. Whether a vomited tablet counts as taken is a question for your pharmacist or prescriber; note the time of both.

Two more points from the label. Orforglipron reaches steady levels after about a week and has a half-life of roughly 29 to 49 hours, so one disrupted day does not reset the medicine in your body (section 12.3) ^[1]. And because it slows the stomach, it can affect other oral medicines. People on a birth control pill are asked to rely on a different, non-oral method, or to add a barrier method, for the first 30 days and again for 30 days following every step up (section 7.3) ^[1]. The label does not discuss what vomiting itself does to the pill, so ask your pharmacist.

Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Eli Lilly and Company.

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