Phase 3 · Orforglipron

ATTAIN-1 trial results

A Phase 3, Randomized, Double-Blind Study to Investigate the Efficacy and Safety of Once-Daily Oral Orforglipron Compared With Placebo in Adult Participants With Obesity or Overweight With Weight-Related Comorbidities (ATTAIN-1)

Percent Change From Baseline in Body Weight (Primary Treatment Period) (percent change), Baseline, Week 72. Placebo: -0.87; 6 mg Orforglipron: -7.82; 12 mg Orforglipron: -9.27; 36 mg Orforglipron: -12.35.

Participants: 3,127
Status: active, not recruiting
Completed: 2027-10
Sponsor: Eli Lilly and Company

As posted on ClinicalTrials.gov (NCT05869903), updated at source Aug 14, 2026. Read again whenever the registry updates it. Registry figures can differ from a published paper, which may use another analysis.

Primary outcome

What ATTAIN-1 measured first

Percent Change From Baseline in Body Weight (Primary Treatment Period)percent change · Baseline, Week 72 · least squares mean

Placebon=949	6 mg Orforglipronn=723	12 mg Orforglipronn=725	36 mg Orforglipronn=730
-0.87(0.247)	-7.82(0.302)	-9.27(0.335)	-12.35(0.364)

Side effects by arm

Side effects in ATTAIN-1

Percent of participants affected, Baseline Up to Week 74. The most common events the registry lists.

Event	Placebo	6 mg Orforglipron	12 mg Orforglipron	36 mg Orforglipron
Any serious event	4.9%	5.5%	5.4%	3.8%
Nausea	10.4%	28.9%	35.9%	33.7%
Constipation	9.3%	21.6%	29.8%	25.4%
Vomiting	3.5%	13%	21.4%	24%
Diarrhoea	9.6%	21%	22.8%	23.1%
Dyspepsia	5%	13.1%	16.2%	14.1%
Upper respiratory tract infection	10.9%	10.4%	10.4%	8.8%
Headache	7.5%	8.6%	10.4%	9.8%
Abdominal distension	3.4%	7.2%	9.4%	8.5%
Influenza	7.7%	9.4%	8%	6%
Nasopharyngitis	7.8%	7.6%	8.4%	6.5%
Decreased appetite	3.2%	5.8%	8.4%	7.3%
Abdominal pain upper	3.5%	6.1%	6.2%	7.8%
Eructation	1.1%	6.1%	5.9%	7.6%
Covid-19	5.3%	6.1%	7.2%	7.4%
Abdominal pain	2.6%	5.3%	6.9%	6%
Gastroenteritis	3.8%	6.1%	5.7%	6.9%
Anxiety	6.8%	5.1%	4%	3.7%
Gastrooesophageal reflux disease	2.2%	5.5%	5.8%	6.3%
Arthralgia	6.3%	4.7%	5.1%	4.8%
Back pain	5.7%	4.6%	5.2%	6.2%
Flatulence	1.8%	4.3%	5.5%	5.6%
Alopecia	2.4%	4.1%	5%	5.4%
Fatigue	1.6%	3.6%	3.5%	5.1%

Secondary outcomes

What else it measured

Change From Baseline in Waist Circumference (Primary Treatment Period)centimeters · Baseline, Week 72 · least squares mean

Placebon=949	6 mg Orforglipronn=723	12 mg Orforglipronn=725	36 mg Orforglipronn=730
-2.09(0.260)	-7.54(0.305)	-9.00(0.318)	-11.13(0.318)

Change From Baseline in Systolic Blood Pressure (SBP) (Pooled Doses of Orforglipron 6 mg, 12 mg and 36 mg) - Primary Treatment Periodmillimeters of mercury (mmHg) · Baseline, Week 72 · least squares mean

Placebon=949	Pooled 6 mg/12 mg/36 mg Orforglipronn=2,178
-0.78(0.404)	-6.14(0.283)

Percent Change From Baseline in Non-High Density Lipoprotein (Non-HDL) Cholesterol (Pooled Doses of Orforglipron 6 mg, 12 mg and 36 mg) - Primary Treatment Periodpercent change · Baseline, Week 72 · geometric least squares mean

Placebon=936	Pooled 6 mg/12 mg/36 mg Orforglipronn=2,146
-1.41(0.715)	-7.57(0.454)

Percent Change From Baseline in Triglycerides (Pooled Doses of Orforglipron 6 mg, 12 mg and 36 mg) - Primary Treatment Periodpercent change · Baseline, Week 72 · geometric least squares mean

Placebon=936	Pooled 6 mg/12 mg/36 mg Orforglipronn=2,142
-4.8(1.21)	-16.4(0.74)

Change From Baseline in HbA1c (Primary Treatment Period)percentage of HbA1c · Baseline, Week 72 · least squares mean

Placebon=948	6 mg Orforglipronn=722	12 mg Orforglipronn=724	36 mg Orforglipronn=730
-0.03(0.010)	-0.31(0.010)	-0.31(0.010)	-0.38(0.011)

Change From Baseline in Fasting Serum Glucose (FSG) (Primary Treatment Period)milligram per deciliter (mg/dL) · Baseline, Week 72 · least squares mean

Placebon=949	6 mg Orforglipronn=723	12 mg Orforglipronn=725	36 mg Orforglipronn=730
0.28(0.407)	-7.68(0.341)	-8.70(0.334)	-9.25(0.378)

Percent Change From Baseline in Fasting Insulin (Primary Treatment Period)percent change · Baseline, Week 72 · geometric least squares mean

Placebon=948	6 mg Orforglipronn=723	12 mg Orforglipronn=724	36 mg Orforglipronn=730
-7.30(2.211)	-20.64(1.967)	-23.87(2.047)	-32.78(1.875)

Change From Baseline in Diastolic Blood Pressure (DBP) (Pooled Doses of Orforglipron 6 mg, 12 mg and 36 mg) - Primary Treatment Periodmillimeters of mercury (mmHg) · Baseline, Week 72 · least squares mean

Placebon=949	Pooled 6 mg/12 mg/36 mg Orforglipronn=2,178
-0.93(0.273)	-2.53(0.194)

Change From Baseline in Short Form-36 Health Survey Version 2 (SF-36v2) Acute Form (Physical Component and Mental Component) Scores - (Pooled Doses of Orforglipron 6 mg, 12 mg and 36 mg) - Primary Treatment PeriodT-score · Baseline, Week 72 · least squares mean

Measure	Placebon=949	Pooled 6 mg/12 mg/36 mg Orforglipronn=2,175
Physical Component Score	0.76(0.232)	2.28(0.131)
Mental Component Score	-1.08(0.244)	-0.65(0.157)

The trial

How ATTAIN-1 was run

This study will investigate the efficacy and safety of once daily oral orforglipron in adult participants with obesity or overweight with weight-related comorbidities. The study has two phases: a main phase and an extension phase. The main phase of the study lasted 72 weeks. Participants with prediabetes will continue in the extension for another 2 years.

Placebo: Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received orforglipron-matching placebo, administered orally once daily (QD), for a period of 72 weeks.
6 mg Orforglipron: Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received orforglipron, administered orally QD, starting at a dose of 1 milligrams (mg) and escalated every 4 weeks until reaching a dose of 6 mg at week 8, which was then maintained up to week 72.
12 mg Orforglipron: Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received orforglipron, administered orally QD, starting at a dose of 1 mg and escalated every 4 weeks until reaching a dose of 12 mg at week 12, which was then maintained up to week 72.
36 mg Orforglipron: Primary Treatment Period (Week 0-Week 72): Participants with normoglycemia or prediabetes at the time of randomization received orforglipron, administered orally QD, starting at a dose of 1 mg and escalated every 4 weeks until reaching a dose of 36 mg at week 20, which was then maintained up to week 72.

Who could join the trial

Inclusion Criteria: * Have a BMI * ≥30.0 kilogram/square meter (kg/m²), * ≥27.0 kg/m² and presence of at least 1 of the following weight-related comorbidities (treated or untreated) at screening: * Hypertension, dyslipidemia, obstructive sleep apnea, cardiovascular disease (for example, ischemic cardiovascular disease, New York Heart Association Functional Class I-III heart failure). * Have a history of at least 1 self-reported unsuccessful dietary effort to lose body weight. Exclusion Criteria: * Have Type 1 diabetes, Type 2 diabetes, or any other types of diabetes, history of ketoacidosis, or hyperosmolar state/coma * Have a self-reported change in body weight \>5 kg (11 pounds) within 90 days prior to screening. * Have family (first-degree relative) or personal history of medullary thyroid cancer (MTC) or multiple endocrine neoplasia (MEN)2 syndrome. * Have had a history of chronic or acute pancreatitis.

Published papers

Papers from ATTAIN-1

Trial averages do not predict what one person will experience. Results are shown as the registry posts them, without interpretation.

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