Three related findings from section 6.1
These figures come from the “other adverse reactions” paragraphs of section 6.1, not from Table 1, and are given for all Foundayo™ doses combined rather than dose by dose [1]. The pool is Trials 1 and 2: adults with obesity or overweight, a third of them with type 2 diabetes, followed for up to 72 weeks.
Outside the US, Europe’s opinion summary of October 2026 names only stomach and bowel effects as the most common side effects, and with no EMA product information yet there is no EU band for dizziness; Health Canada has no Foundayo™ entry [3][4].
| Finding | Foundayo™ | Placebo |
|---|---|---|
| Dizziness | 4% | 3% |
| Hypotension (low blood pressure) | 2% | 0.5% |
| Tachycardia (fast heart rate) | 3% | 0.9% |
Dizziness itself: a narrow gap
One extra person in a hundred reported dizziness on the tablet compared with placebo [1]. That is why it sits outside the main table, which requires at least 5% of treated adults. On its own, the dizziness figure suggests a modest effect; the blood pressure data give it more context.
Blood pressure falls, especially with other treatment
Low blood pressure was reported four times as often on Foundayo™ as on placebo [1]. The label adds a detail that matters for many people: among those on Foundayo™, hypotension was seen in 4% of people who also took antihypertensive medicines, against 1% of those who did not. Half of the pooled population had high blood pressure at the start [1].
Table 7 in section 14 shows the average change. In Trial 1, systolic blood pressure fell by 5.7, 5.1 and 6.4 mm Hg on 5.5 mg, 9 mg and 17.2 mg, against 1.4 mm Hg on placebo. In Trial 2, in people with type 2 diabetes, the falls were 4, 4.2 and 4.6 mm Hg, against 1.5 mm Hg. Diastolic pressure moved much less: in Trial 1 it fell by 2.3 to 2.7 mm Hg on the three doses, against 1.4 on placebo [1]. The ATTAIN-1 publication likewise reports a significant improvement in systolic pressure with orforglipron [9].
The same section reports tachycardia in 3% against 0.9% and an average rise in heart rate of 4 to 5 beats per minute [1]; the Foundayo™ palpitations page looks at that finding in detail.
Dizziness in the trial registries
ATTAIN-1 and ATTAIN-2 post non-serious events only when a group reached 5%, but they list every serious event; ACHIEVE-1 and ACHIEVE-5, two 40-week double-blind trials in type 2 diabetes, post every event [5][6][7][8]. The ATTAIN doses of 6, 12 and 36 mg correspond to Foundayo™ 5.5, 9 and 17.2 mg [1]; the ACHIEVE trials used 3, 12 and 36 mg [7][8].
| Trial [source] | Setting | Placebo | Orforglipron, by rising dose |
|---|---|---|---|
| ATTAIN-1 [5] | Obesity without diabetes, 72 weeks | Dizziness not listed (below 5% in every group) | Not listed |
| ATTAIN-2 [6] | Obesity with type 2 diabetes, 72 weeks | Dizziness 18/628 (2.9%); serious fainting 2/628 | Dizziness 19/328 (5.8%), 11/331 (3.3%), 22/321 (6.9%); serious hypotension 1/328; serious orthostatic hypotension 1/321; serious fainting 1/331 |
| ACHIEVE-1 [7] | Early type 2 diabetes, 40 weeks | Dizziness 2/138 (1.4%); falls 0 | Dizziness 6/143 (4.2%), 4/137 (2.9%), 5/141 (3.5%); falls 0, 2 and 2; fainting 2/141 on the highest dose |
| ACHIEVE-5 [8] | Type 2 diabetes on insulin glargine, 40 weeks | Dizziness 6/140 (4.3%); falls 2/140 | Dizziness 8/137 (5.8%), 3/132 (2.3%), 3/135 (2.2%); falls 0, 0 and 1 |
What the registry rows suggest
- Dizziness did not climb steadily with dose in any trial. In ATTAIN-2 the middle dose had the lowest rate, and in ACHIEVE-5 two of the three orforglipron groups were below placebo [6][8].
- In ATTAIN-2, two of the three orforglipron groups were above the label’s pooled 4%, a reminder that a pooled figure can hide variation between trials [1][6].
- Serious low blood pressure or fainting was rare: single cases per group, with serious fainting also seen on placebo [6].
- Falls were too few to compare: two per orforglipron group at most in ACHIEVE-1, and two on placebo in ACHIEVE-5 [7][8].
Other label warnings that can feel similar
- Low blood sugar: in the trial of adults with type 2 diabetes, glucose under 54 mg/dL occurred in 2% on Foundayo™ against 0.2% on placebo, and 7% of those also taking a sulfonylurea reported hypoglycemia [1]. The Medication Guide puts dizziness or light-headedness first among its signs, along with sweating, shakiness, hunger, confusion and a fast heartbeat [2].
- Fluid loss: section 5.4 links dehydration from vomiting, diarrhea or nausea to acute kidney injury and asks for kidney checks, especially during dose increases [1]. MedlinePlus lists dizziness and a rapid heartbeat among signs of severe dehydration, and notes that providers look for blood pressure that drops on standing [12].
- Allergic reactions: serious hypersensitivity, including anaphylaxis, is a label warning [1]. The Medication Guide includes fainting or feeling dizzy and a very rapid heartbeat among its signs, together with swelling of the face or throat and trouble breathing or swallowing [2].
Why Foundayo™ might leave you light-headed
- Supported by the label: average blood pressure fell more on Foundayo™ than on placebo, and low blood pressure was reported more often, especially alongside blood pressure medicines [1]. MedlinePlus explains that light-headedness occurs when the brain does not get enough blood, for example after a sudden drop in blood pressure [10].
- Plausible but not measured: Foundayo™ lowers food intake [1], and MedlinePlus notes that feeling nauseated can stop people drinking enough, which leads to dehydration [12]. Whether this explains any of the dizziness in the trials was not studied, and the label does not say why blood pressure falls.
- General background: MedlinePlus says most causes of dizziness are not serious and either settle quickly or are easy to treat [10].
Other reasons people feel dizzy
MedlinePlus separates feeling faint (lightheadedness) from a spinning sensation (vertigo) [10]:
- Lightheadedness: getting up too quickly, dehydration from vomiting, diarrhea or fever, flu, colds, allergies, low blood sugar and medicines that lower blood pressure.
- Vertigo: benign positional vertigo when the head moves, inner-ear infection (labyrinthitis) and Ménière disease.
- Less common but serious: heart problems such as an abnormal heartbeat, stroke, internal bleeding and shock, which usually come with other symptoms such as chest pain, a racing heart or a change in speech or vision.
Standing up, fluids and falls: general advice
Cleveland Clinic says dizziness on standing becomes more common after 65 and is more likely with heart conditions, diabetes, anaemia, Parkinson’s disease, long bed rest and medicines for high blood pressure or depression [11].
For lightheadedness on standing, MedlinePlus suggests avoiding sudden changes of position, getting up slowly from lying down, sitting for a few moments before standing and having something to hold [10]. Cleveland Clinic adds staying hydrated, limiting alcohol, avoiding very hot baths and heavy high-carbohydrate meals, raising the head of the bed and moving your leg muscles before you stand [11].
Cleveland Clinic warns that dizziness on standing raises the chance of falls, fractures and head injuries [11], and MedlinePlus advises against driving, operating heavy machinery or climbing for a period after a vertigo spell, because a sudden attack during them can be dangerous [10]. The Foundayo™ label makes no statement about driving. Cleveland Clinic also notes that treatment can mean changing the dose of another medicine [11]; that is a decision for your prescriber, not one to make on your own.
Gaps in the evidence
- Dizziness, low blood pressure and tachycardia are given only for all Foundayo™ doses together, not dose by dose [1].
- The label does not say when the fall in blood pressure begins, or whether dizziness fades with time [1].
- Of the people treated with Foundayo™ in the pool, 13% were 65 or older and 1% were 75 or older; the label reports no overall safety differences by age, but falls are not analysed [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 |
|---|---|---|---|
| Dizziness with chest pain, an irregular heartbeat, shortness of breath, weakness, trouble moving an arm or leg, a change in vision or speech, or trouble keeping fluids down | Emergency care (911 or your local number) | Emergency | MedlinePlus, dizziness [10] |
| Feeling faint or dizzy while your face, lips, tongue or throat swell, or while breathing or swallowing is difficult | Stop Foundayo™ and get emergency help | Emergency | Foundayo™ Medication Guide [2] |
| Fainting, a fall with a possible fracture or head injury, or cold, sweaty skin with a weak pulse | Immediate medical care | Emergency | Cleveland Clinic [11] |
| Light-headedness with sweating, shakiness, hunger or confusion, especially on insulin or a sulfonylurea | Treat low blood sugar as you were taught, then contact your provider | Today | Medication Guide [2] |
| Dizziness with nausea, vomiting or diarrhea that does not settle, or passing much less urine | Your prescriber, the same day | Today | Medication Guide [2]; MedlinePlus [12] |
| Dizziness for the first time, after a new medicine, or symptoms that are new or getting worse | Your healthcare provider | Today | MedlinePlus [10] |
| Getting dizzy often when you stand up, even if only some of the time | Your healthcare provider | At your next appointment | Cleveland Clinic [11] |
