Constipation on Foundayo™

Where the numbers come from

Section 6.1 reports a pool of 3,155 adults treated with Foundayo™ and 1,576 on placebo across Trials 1 and 2, followed for up to 72 weeks plus two weeks off the drug ^[1]. Average age was 49, and about a third had type 2 diabetes ^[1]. Constipation appeared in at least one in five people on every Foundayo™ dose, and the Medication Guide counts it among the most common side effects ^[1][2].

There is no second set of official figures to compare. The EMA committee’s positive opinion of 15 October 2026 sums up side effects in one line, and frequency bands belong in EMA product information, which does not exist yet; Health Canada has no listing at all ^[3][4].

The middle dose came out highest

Most reactions in the table either rise with the dose or stay level. Constipation does neither: it was most common on 9 mg and slightly less common on 17.2 mg ^[1]. The label offers no explanation and does not say whether a three-point gap between two large groups is meaningful. What the table does show clearly is that every dose roughly doubled to tripled the placebo rate.

Remember also that the 17.2 mg group reached that dose only after several 30-day steps, so people in each group spent weeks on lower strengths before arriving at their assigned dose ^[1].

The label gives no stopping rate for constipation alone. All stomach and bowel reactions together led 3% of people on 5.5 mg and 6% on 9 mg or 17.2 mg to stop treatment, compared with 0.7% on placebo ^[1].

Two trials, two curves, and the serious cases

The registry for each weight trial separates the pool. Both list non-serious events only once they reach 5% in a group, but they list every serious event ^[5][6]. Their trial doses of 6, 12 and 36 mg correspond to the 5.5, 9 and 17.2 mg strengths in the label ^[1].

• The 9 mg peak in the label comes mainly from ATTAIN-1. In ATTAIN-2, constipation was lower at every dose and crept up with each one ^[5][6].
• Placebo rates were 9.3% and 7.8%, so the background level was similar in both populations ^[5][6].
• Four serious bowel events among 3,155 people on orforglipron are too few to estimate a rate, and the registry entries do not describe how each case ended ^[5][6].

Ileus, blockage and impaction in the wider class

Section 6.2 lists reports from the use of GLP-1 receptor agonists after approval, not from the Foundayo™ trials. Under stomach and bowel disorders it names ileus, intestinal obstruction and severe constipation including fecal impaction ^[1]. Because these reports are voluntary, the label says their frequency cannot be reliably estimated and a causal link cannot always be established ^[1].

MedlinePlus explains the difference between the terms. A mechanical obstruction means something is blocking the bowel, impacted stool among the possible causes, while ileus is a bowel that is not moving properly even though nothing physical blocks it ^[10]. Swelling of the belly, cramping pain, being unable to pass gas, nausea and vomiting are among the symptoms it lists ^[10].

Separately, section 5.3 warns that stomach and bowel reactions on Foundayo™ are sometimes severe: about 3% on orforglipron against 1% on placebo in trials. The label does not recommend the tablet for people with severe gastroparesis ^[1].

A timing sentence that leaves it out

The label’s comment on timing covers nausea, vomiting and diarrhea, which were more frequent during escalation and decreased afterwards ^[1]. Constipation is not in that sentence. The prescribing information neither says it fades nor says it persists, so it gives no basis for expecting it to settle on a schedule.

Why a weight tablet may slow the bowel

From the label: Foundayo™ delays stomach emptying, most after the first dose, and decreases food intake, an effect the label puts down to reduced appetite ^[1]. The label describes these effects on the stomach and on eating; it does not draw a line from either to constipation.

Plausible but not measured: NIH lists not eating enough fibre, not drinking enough liquids and changing how much and what you eat among causes of constipation ^[7]. Eating less on the tablet could feed into all three, but no orforglipron study has tested that chain.

General background: NIH also names diabetes, an underactive thyroid and too little physical activity as contributors ^[7]. About a third of the label’s pool had type 2 diabetes ^[1], one reason the placebo groups reported constipation too.

Other things that slow you down

NIH’s list of medicines and supplements that can worsen constipation includes antacids with aluminium or calcium, iron supplements, narcotic pain medicines, some antidepressants, anticonvulsants, calcium channel blockers, diuretics and medicines for Parkinson’s disease ^[7]. Life changes count as well: pregnancy, travel, getting older, ignoring the urge to go and changing your medicines ^[7]. Irritable bowel syndrome, coeliac disease, pelvic floor problems and, less often, a blockage or tumour in the bowel are further causes NIH names ^[7].

MedlinePlus adds that some vitamins can constipate, and that knowing your normal bowel pattern helps you spot a change before it gets worse ^[11].

What NIH guidance suggests

NIH says constipation can most often be treated at home: eat more high-fibre foods such as whole grains, beans and lentils, fruit, vegetables and nuts, drink plenty of water and other liquids as you add fibre, keep up regular physical activity and try to go at the same time each day, giving yourself enough time ^[8][9]. MedlinePlus suggests adding fibre slowly, because a sudden increase can cause gas and bloating, not skipping meals and going as soon as you feel the urge ^[11].

Laxatives are a pharmacist’s or prescriber’s call. NIH lists fibre supplements, osmotic agents, stool softeners, lubricants and stimulants, says a health professional may suggest one for a short time and will tell you which type suits you, and keeps stimulants for severe constipation or when other treatments have not worked ^[8]. MedlinePlus advises against a laxative if you have severe stomach pain, nausea or vomiting, and against using one for more than a week without your provider ^[11]. NIH also asks you not to stop or change any medicine without talking to a health professional first ^[8].

Two label points apply. Foundayo™ is taken with or without food, so it sets no fasting window around fibre or laxatives ^[1]. It does slow stomach emptying, which can change how other oral medicines are absorbed, and the Medication Guide asks you to tell your provider about non-prescription products too ^[1][2].

Tablet details worth knowing

The Medication Guide asks you to let your provider know when stomach trouble turns severe or lingers ^[2], and constipation that drags on falls under that. Strong CYP3A4 inhibitors raise orforglipron levels and may increase its side effects, so the label caps the dose at 9 mg when one is used ^[1]; a full medicine list helps your prescriber spot them.

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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