The two gallbladder figures
Both numbers come from the pool of Trials 1 and 2, in which adults with obesity or overweight were treated for up to 72 weeks. They are given for all Foundayo™ doses together, in section 5.8 and again in section 6.1 [1]. The Medication Guide says gallbladder problems have happened in some people who use the tablet [2].
There is no European or Canadian figure to set beside them. The EMA committee’s positive opinion of 15 October 2026 has not yet become product information, and Health Canada lists no Foundayo™ or orforglipron product [3][4].
| Event | Foundayo™ | Placebo |
|---|---|---|
| Gallstones (cholelithiasis) | 1% | 0.7% |
| Acute cholecystitis (inflamed gallbladder) | 0.4% | 0.3% |
Small gaps, still a warning
The difference from placebo was a fraction of a percentage point for each event. So why is it a formal warning? Section 5.8 frames it as an effect seen with Foundayo™ and with GLP-1 receptor agonists as a class, and the list of serious adverse reactions at the start of section 6 includes acute gallbladder disease alongside pancreatitis and kidney injury [1].
The label does not explain its reasoning beyond that, and it does not grade how serious the trial cases were. What it does make clear is that this is a class-wide finding, not something unique to the tablet.
Serious cases in the trial registries
The registries for the two weight trials list every serious adverse event, but non-serious ones only once they reach 5% of a group, which no gallbladder term did [5][6]. The table therefore shows serious cases only. ATTAIN-1 had 948 people on placebo and 723 to 728 in each orforglipron group; ATTAIN-2 had 628 on placebo and 321 to 331 per group. Their trial doses of 6, 12 and 36 mg correspond to 5.5, 9 and 17.2 mg [1].
- These are counts per term, not per person: one person can appear in more than one row, so the rows cannot simply be added up.
- Acute cholecystitis was the most frequent serious term, with eight cases on orforglipron across both trials and three on placebo; both necrotic cases were on placebo [5][6].
- The numbers are too small to show a dose pattern. The label’s 1% and 0.4% are higher than these serious counts alone, which suggests they also include non-serious reports [1][5][6].
| Trial and term | Placebo | 5.5 mg | 9 mg | 17.2 mg |
|---|---|---|---|---|
| ATTAIN-1: acute cholecystitis [5] | 1 | 1 | 1 | 3 |
| ATTAIN-1: necrotic acute cholecystitis [5] | 1 | 0 | 0 | 0 |
| ATTAIN-1: chronic cholecystitis [5] | 0 | 0 | 2 | 0 |
| ATTAIN-1: gallstones [5] | 1 | 1 | 1 | 2 |
| ATTAIN-1: biliary colic (gallbladder attack) [5] | 0 | 0 | 0 | 1 |
| ATTAIN-2: acute cholecystitis [6] | 2 | 1 | 1 | 1 |
| ATTAIN-2: necrotic acute cholecystitis [6] | 1 | 0 | 0 | 0 |
| ATTAIN-2: gallstones [6] | 1 | 0 | 2 | 1 |
| ATTAIN-2: bile duct stone [6] | 0 | 0 | 0 | 1 |
Weight loss as the link
Backed by the label: acute gallbladder events were associated with weight reduction, and the label does not describe a direct effect of orforglipron on the gallbladder [1]. Weight reduction on the tablet was substantial: Table 6 shows that in Trial 1, 54.5% of people on 17.2 mg lost at least 10% of their starting weight after 72 weeks, against 13% on placebo, and in Trial 2, among people with type 2 diabetes, 45.6% against 9.2% [1].
General knowledge from NIH: when you lose weight quickly or go a long time without eating, the liver releases extra cholesterol into the bile, and fast weight loss can also stop the gallbladder emptying properly [9]. NIH adds that obesity itself makes gallstones more likely [7][9].
Not measured: the label gives no gallbladder rates by dose or by amount of weight lost, and no orforglipron study has tested whether the speed of loss explains these cases [1]. Section 12.2 adds only that the weight lost on the tablet was more fat than lean mass [1].
What a gallbladder problem feels like
The Medication Guide asks you to tell your provider straight away about possible gallbladder symptoms and lists four: pain in the upper stomach, fever, yellowing of the skin or eyes, and clay-coloured stools [2]. NIH describes a gallbladder attack as pain in the upper right abdomen, sometimes lasting several hours, often after heavy meals and in the evening or at night, and says more attacks tend to follow a first one [8]. MedlinePlus adds that the pain can be constant or cramping and may come with nausea and vomiting [10].
Most gallstones cause no symptoms at all; NIH calls these silent stones and says they usually need no treatment [7][8].
Severe stomach pain that will not go away, sometimes spreading to the back, is the pattern the label describes for pancreatitis, a separate warning covered on PepLabo’s Foundayo™ pancreatitis page, and NIH notes that a gallstone blockage can itself inflame the pancreas [1][7].
Who gets gallstones anyway
Gallstones are common with or without any medicine. NIH lists women, older people, people with a family history, some groups such as American Indians and Mexican Americans, and people with obesity, diabetes or insulin resistance, high triglycerides, low HDL cholesterol, cirrhosis or Crohn’s disease as more likely to develop them [7]. Extra oestrogen from pregnancy, hormone therapy or birth control pills raises the chance too [7].
Upper abdominal pain also has other causes. NIH says gallstone symptoms can resemble appendicitis, ulcers, pancreatitis and reflux disease, all of which need a doctor’s assessment soon [8].
What NIH says about eating and pace
NIH suggests more high-fibre foods such as fruit, vegetables, beans and whole grains, fewer refined carbohydrates and less sugar, healthy fats such as fish oil and olive oil that help the gallbladder contract and empty regularly, and fewer unhealthy fats such as those in fried foods and desserts [11]. It also encourages regular physical activity and warns against crash diets and repeated cycles of losing and regaining weight [9][11].
NIH’s advice on losing weight slowly was written for diets and surgery. On Foundayo™ the pace of loss is tied to a dose plan that only your prescriber sets, so raise any concern about it with them rather than changing how you take the tablet [1][9]. NIH also asks you to talk with a health professional before changing your eating plan [11].
What the label asks of clinicians
If cholecystitis is suspected, section 5.8 calls for gallbladder diagnostic studies and suitable clinical follow-up. It does not ask for routine gallbladder scans before or during treatment, and it does not say to stop the tablet automatically; those decisions are left to the treating clinician [1]. Section 17 asks prescribers to tell patients about the risk and to have them make contact for follow-up if gallbladder disease is suspected [1].
The label does not say how far into treatment the events occurred or how many trial cases needed surgery [1].
Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Eli Lilly and Company.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| Severe pain across the stomach area that will not settle, sometimes boring through to the back | Stop Foundayo™ and get medical help straight away | Emergency | Medication Guide [2] |
| Upper right belly pain lasting hours together with fever, chills or vomiting | A doctor straight away, the same day | Today | NIDDK [8] |
| Jaundice (yellowing of skin or eyes), dark tea-like urine or clay-coloured stools | Your provider straight away | Today | Medication Guide [2]; NIDDK [8] |
| Bouts of cramping pain in the upper right abdomen after meals that ease on their own | Your prescriber soon, to look for gallstones | At your next appointment | NIDDK [8]; MedlinePlus [10] |
| Gallstones already known, or found on a scan, before or during treatment | Your prescriber at the next visit | At your next appointment | NIDDK [9] |