Orforglipron Dosage, half-life & reference guide

Also known as Foundayo · LY3502970 · Orfo

A GLP-1 drug in a once-daily tablet that is not a peptide, so it comes with no fasting or water rules: Lilly's Foundayo, FDA-approved in April 2026 for weight management. Its label strengths (0.8 to 17.2 mg) look different from the trial doses because the marketed tablet is a new formulation; the trials' 36 mg is the label's 17.2 mg.

FDA label: 0.8–17.2 mgstarting dose 0.8 mg
How often: Daily
Half-life: ~29–49 hours
Evidence: ●●● Established
Route: Oral tablet

Orforglipron dose guide

How it works.

Small-molecule (non-peptide) GLP-1 receptor agonist taken as a daily tablet. Because it is a small molecule it is absorbed without the fasting and water rules of oral semaglutide: the label puts its absolute bioavailability at 77% and lets it be taken with or without food. It reduces food intake, likely by lowering appetite, and delays stomach emptying, most after the first dose; in animal studies it reached and activated brain regions that regulate appetite. FDA-approved on April 1, 2026, as Foundayo for chronic weight management, at 0.8 to 17.2 mg once daily.

Commonly reported: The easy routine is the main draw, with nausea, constipation or burping mostly in the weeks after each step-up. Its top dose averaged about 11% weight loss at 72 weeks in its main trial.

Half-life & active level

The half-life of Orforglipron is ~29–49 hours (FDA label; steady levels after about a week of daily tablets).

Here's how a typical Orforglipron schedule accumulates over four weeks (one-compartment estimate).

An estimate from the half-life above, not a measurement. See your own curve build live in the half-life calculator.

Week by week.

What to expect in the first 8 weeks

Onset: Days–2 weeks
Peak effect: 72 weeks (trial endpoint)
Duration: Ongoing

Day 1–30 · 0.8 mgRCT
The 0.8 mg start
You're on 0.8 mg, the label's starting dose: one tablet a day, with or without food. It is a run-in that lets your gut adjust. Commonly reported: a little nausea or less appetite in the first weeks.
The science
The Foundayo label (effective July 2026) starts at 0.8 mg daily for at least 30 days, then 2.5 mg, then 5.5 mg, to reduce GI side effects. The slowing of stomach emptying is largest after the first dose and fades over time. Food lowers exposure only modestly (AUC about 18–24% lower fed than fasted), so there are no meal rules (label; Ma 2024).
Sources
- FDA Foundayo label (2026)
- Ma et al. (2024)
Updated Oct 2026
Day 31–60 · 2.5 mgRCT
2.5 mg, the second step
At 2.5 mg, commonly reported: appetite noticeably quieter and meals ending sooner, with nausea or constipation for some in the days after the step-up.
The science
In the weight trials, nausea, vomiting and diarrhea were most frequent during the dose climb and decreased over time (label). Across the maintenance doses, constipation affected 20–27% vs 9% on placebo, and nausea 26–35% vs 10% (label table).
Sources
- FDA Foundayo label (2026)
Updated Oct 2026
Any dayRCT
What Orforglipron is built on
Orforglipron rests on phase 3 trials in more than 10,000 people with obesity or type 2 diabetes, including a heart-safety trial, and it lowered HbA1c more than oral semaglutide head to head. It was FDA-approved for weight management on April 1, 2026, as Foundayo.
The science
ATTAIN-1 (Wharton 2025) and ATTAIN-2 (Horn 2025) support the weight indication. ACHIEVE-1 (Rosenstock 2025): HbA1c −1.24 to −1.48 points vs −0.41 at 40 weeks. ACHIEVE-3 (Rosenstock 2026): HbA1c −1.71 (12 mg) and −1.91 (36 mg) vs −1.23 and −1.47 on oral semaglutide 7 and 14 mg, with more GI events (58–59% vs 37–45%) and larger pulse rises (3.7–4.7 vs 1.0–1.5 bpm). ACHIEVE-4 (Klein 2026): major cardiovascular events non-inferior to insulin glargine (HR 0.84). Type 2 diabetes is not yet on the US label.
Sources
- Wharton et al. (ATTAIN-1) (2025)
- Horn et al. (ATTAIN-2) (2025)
- Rosenstock et al. (ACHIEVE-1) (2025)
- Rosenstock et al. (ACHIEVE-3) (2026)
- Klein et al. (ACHIEVE-4) (2026)
Updated Oct 2026
With Tirzepatide and SemaglutideRCT
Switching from a weekly shot to the pill
People who had plateaued on tirzepatide or semaglutide and switched to orforglipron, in place of the shot, kept about 75–79% of their weight loss for a year, against 38–49% on placebo.
The science
ATTAIN-MAINTAIN (Aronne 2026): 376 people from SURMOUNT-5 who had plateaued on tirzepatide (n=205) or semaglutide (n=171) were randomized to daily orforglipron or placebo. At week 52 they kept 74.7% (from tirzepatide) and 79.3% (from semaglutide) of their weight reduction on orforglipron vs 49.2% and 37.6% on placebo. No arm stayed on the injection, and taking a shot and the pill together was not studied; the label advises against combining GLP-1 drugs.
Sources
- Aronne et al. (ATTAIN-MAINTAIN) (2026)
- FDA Foundayo label (2026)
Updated Oct 2026

After week 8

Day 61+ · 5.5 mgRCT
5.5 mg, the first maintenance dose
5.5 mg is the first step the label treats as a possible maintenance dose. In ATTAIN-1 its arm averaged 7.4% weight loss at 72 weeks, against 2.1% on placebo.
The science
ATTAIN-1 (Wharton 2025; 3,127 adults without diabetes, 72 weeks) reported −7.5% (6 mg), −8.4% (12 mg) and −11.2% (36 mg) vs −2.1% on placebo, treatment-regimen estimand. The Foundayo label shows these arms as 5.5, 9 and 17.2 mg, the equivalent doses of the marketed tablet (−7.4%, −8.3%, −11.1%). Stopping for side effects: 6% at 5.5 mg vs 3% on placebo (label pool).
Sources
- Wharton et al. (ATTAIN-1) (2025)
- FDA Foundayo label (2026)
Updated Oct 2026
Day 91+ · 9 mgRCT
9 mg, an optional step
9 mg is the next optional step once 5.5 mg is tolerated. Its trial arm averaged 8.3% weight loss at 72 weeks, and 39.8% of people lost at least 10%.
The science
Trial 1 (ATTAIN-1) as shown in the Foundayo label: 9 mg −8.3% vs −2.1% on placebo; at least 10% loss in 39.8% vs 13.0%. Alongside a strong CYP3A4 inhibitor such as clarithromycin, the label caps the dose at 9 mg.
Sources
- FDA Foundayo label (2026)
Updated Oct 2026
Day 121+ · 14.5 mgRCT
14.5 mg, the step before the top
14.5 mg sits between the two higher tested doses, 9 and 17.2 mg, so the trials have no arm of its own. Commonly reported: a few days of extra nausea or burping after each step-up.
The science
Trials 1 and 2 randomized people to 5.5, 9 or 17.2 mg (label); 14.5 mg was a step on the way to 17.2 mg. Burping affected 6–8% and reflux 6–7% across doses vs 1–2% on placebo (label table).
Sources
- FDA Foundayo label (2026)
Updated Oct 2026
Day 151+ · 17.2 mgRCT
17.2 mg, the top dose
17.2 mg is the label's maximum, the dose the trials ran as 36 mg. In ATTAIN-1 it averaged 11.1% weight loss at 72 weeks (2.1% on placebo), and 18.4% of people lost at least 20%.
The science
ATTAIN-1 (Wharton 2025): the 36 mg arm averaged −11.2% at 72 weeks (treatment-regimen), with at least 10% loss in 54.6%, 15% in 36.0% and 20% in 18.4%. In people with type 2 diabetes (ATTAIN-2, Horn 2025) it averaged −9.6% vs −2.5%. ACHIEVE-4 calls the 36 mg capsule equivalent to the 17.2 mg tablet (Klein 2026). Heart rate rose 4–5 beats per minute on average (label).
Sources
- Wharton et al. (ATTAIN-1) (2025)
- Horn et al. (ATTAIN-2) (2025)
- Klein et al. (ACHIEVE-4) (2026)
- FDA Foundayo label (2026)
Updated Oct 2026

Day 1 is the day you start it.

FDA Foundayo label (DailyMed, effective July 2026); phase 3 ATTAIN-1 and -2, ATTAIN-MAINTAIN, ACHIEVE-1, -3 and -4. The label strengths differ from the trial doses (new tablet formulation).

Clinical trial data

A typical run.

Run notes

Cycle: FDA-approved for long-term use alongside diet and activity. ATTAIN-MAINTAIN tested it as the follow-on to weekly injections for keeping weight off.Community practice — opinions vary. Not a clinical recommendation.
Timing: One tablet a day, any time, with or without food, swallowed whole (label). The label climbs from 0.8 mg to 2.5 mg and then 5.5 mg, at least 30 days per step, and may continue to 9, 14.5 or 17.2 mg by response and tolerability. Per the label, a missed dose is taken as soon as possible but never doubled, and after 7 or more missed days in a row the climb restarts at a lower dose.
Route: Oral tablet

Safety.

Common side effects

Nausea
Constipation
Diarrhea
Vomiting
Indigestion
Abdominal pain
Headache
Burping

Interactions

The label advises against combining it with another GLP-1 drug. Orforglipron is cleared mainly by the liver enzyme CYP3A4, so some medicines change its levels: the label caps it at 9 mg alongside a strong CYP3A4 inhibitor (clarithromycin raised exposure 3.5-fold), advises avoiding strong inhibitors that also block OATP1B (such as ritonavir) and strong CYP3A4 inducers (carbamazepine cut exposure by 82%), and limits simvastatin to 20 mg a day (orforglipron doubled its active form). Slower stomach emptying may weaken birth-control pills: the label suggests a non-oral or backup method for 30 days after starting and after each step-up. With insulin or a sulfonylurea, those doses are often lowered to limit low blood sugar. Review all your medicines with your clinician or pharmacist.

Safety notes

The Foundayo label carries the GLP-1 class boxed warning for thyroid C-cell tumors. Other GLP-1 drugs caused them in rodents; orforglipron is not active at the rat or mouse receptor and caused none there, and the human relevance of the finding is not known, so the label rules it out for anyone with a personal or family history of medullary thyroid carcinoma or MEN 2. Its other warnings: acute pancreatitis (confirmed in 6 people on orforglipron vs 1 on placebo in the weight trials), severe GI reactions (about 3% vs 1%), kidney injury from dehydration, low blood sugar (mainly alongside insulin or a sulfonylurea), allergic reactions, a temporary worsening of diabetic retinopathy, gallbladder disease, and food reaching the lungs under anesthesia. Resting heart rate rose 4 to 5 beats per minute on average, and hair shedding, tied to weight loss, was more common in women (7% vs 3% on placebo). These are label findings; review them with your clinician.

Questions people ask.

What is Orforglipron?

How is Orforglipron dosed in research?

The FDA label range for Orforglipron is 0.8–17.2 mg, daily, with a 0.8 mg starting dose.

How long does Orforglipron last?

The half-life of Orforglipron is ~29–49 hours (FDA label; steady levels after about a week of daily tablets).

What do people report on Orforglipron?

Commonly reported on Orforglipron: the easy routine is the main draw, with nausea, constipation or burping mostly in the weeks after each step-up. Its top dose averaged about 11% weight loss at 72 weeks in its main trial.

Is Orforglipron safe?

The research basis for Orforglipron is established: clinical trials or FDA-approved use exists. Common side effects in the library: nausea, constipation, diarrhea, vomiting, indigestion, abdominal pain, headache and burping.

Research.

The literature

Search the latest research

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Reference.

Cadence

Daily

Half-life

~29–49 hours

~29–49 hours (FDA label; steady levels after about a week of daily tablets)

Research basis

●●● Established

Clinical trials or FDA-approved use exists

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Reviewed October 2026How we check the library