Semaglutide Trials in Plain English: SELECT, STEP, SOUL
The biggest average what weight loss did the semaglutide trials show?: 14.9% on semaglutide 2.4 mg weekly in STEP 1, against 2.4% on placebo.
- Major trials here
- 13
- Top average loss
- 14.9%
- Placebo, same trial
- 2.4%
- Biggest A1C drop
- 1.86 points
Wegovy: key facts
Its half-life is about 1 week. Half disappears after 7 days, while roughly 3% remains after five half-lives (35 days).
In STEP 1 over 68 weeks, body weight fell 14.9%, versus 2.4% with placebo.
The maker's price page provides monthly price points in US dollars. These cover list prices and self-pay offers.
Sources: FDA label (DailyMed), healthsystemtracker.org, prnewswire.com 1 2.
Every trial in one table
Open a trial's ClinicalTrials.gov record by selecting its name.
| Trial | Who was in it | People | Weeks | Compared with | Main result | In the label as | NCT number |
|---|---|---|---|---|---|---|---|
| STEP 1 | Adults with obesity or overweight, without diabetes | 1,961 | 68 | placebo | 14.9% weight lost | Study 2 in the Wegovy label | NCT03548935 |
| OASIS 4 | Adults with obesity or overweight, without diabetes | 307 | 64 | placebo | 13.6% weight lost | Study 7 in the Wegovy label | NCT05564117 |
| SURMOUNT-5 | Adults with obesity, without type 2 diabetes | 751 | 72 | semaglutide (Wegovy) | 13.7% weight lost | Not listed | NCT05822830 |
| STEP 2 | Adults with obesity or overweight plus type 2 diabetes | 1,210 | 68 | placebo | 9.6% weight lost | Not listed | NCT03552757 |
| STEP TEENS | Teens aged 12 to 17 with obesity | 201 | 68 | placebo | Not listed | Not listed | NCT04102189 |
| SURPASS-2 | Adults with type 2 diabetes on metformin | 1,879 | 40 | semaglutide 1 mg (Ozempic) | A1C 1.86 points lower | Not listed | NCT03987919 |
| SELECT | Adults 45 and older with heart disease and overweight or obesity, and no diabetes | 17,604 | Not listed | placebo | Heart attack, stroke or death from heart disease | Study 1 in the Wegovy label | NCT03574597 |
| SUSTAIN-6 | Adults with type 2 diabetes, all at high heart risk | 3,297 | 104 | placebo | Heart attack, stroke or death from heart disease | Not listed | NCT01720446 |
| PIONEER 6 | Adults with type 2 diabetes, all at high heart risk | 3,183 | Not listed | placebo | Heart attack, stroke or death from heart disease | Not listed | NCT02692716 |
| SOUL | Adults 50 and older with type 2 diabetes plus heart or kidney disease | 9,650 | Not listed | placebo | Heart attack, stroke or death from heart disease | Not listed | NCT03914326 |
| FLOW | Adults with type 2 diabetes and chronic kidney disease | 3,533 | Not listed | placebo | Kidney failure, a large drop in kidney function, or death from kidney or heart causes | Not listed | NCT03819153 |
| STEP-HFpEF | Adults with heart failure and preserved ejection fraction, plus obesity | 529 | 52 | placebo | Not listed | Not listed | NCT04788511 |
| ESSENCE | Adults with MASH (fatty liver inflammation), plus scarring that was moderate to advanced | 800 | 72 | placebo | MASH resolved without worse scarring | Not listed | NCT04822181 |
What weight loss did the semaglutide trials show?
The average share of body weight lost, measured at the end of each trial. Each trial enrolled a different group of people, so compare doses within a single trial first.
| Trial | Dose group | Average weight lost | Placebo or comparison | Weeks | Who was in it |
|---|---|---|---|---|---|
| STEP 1 | Semaglutide 2.4 mg weekly | 14.9% | 2.4% | 68 | Adults with obesity or overweight, without diabetes |
| OASIS 4 | Wegovy pill 25 mg daily | 13.6% | 2.4% | 64 | Adults with obesity or overweight, without diabetes |
| SURMOUNT-5 | Semaglutide 1.7 or 2.4 mg weekly (Wegovy) | 13.7% | semaglutide (Wegovy) | 72 | Adults with obesity, without type 2 diabetes |
| STEP 2 | Semaglutide 2.4 mg weekly | 9.6% | 3.4% | 68 | Adults with obesity or overweight plus type 2 diabetes |
| STEP-HFpEF | Semaglutide 2.4 mg weekly | 13.3% | 2.6% | 52 | Adults with heart failure and preserved ejection fraction, plus obesity |
Sources: STEP 1 (FDA label (DailyMed)), SURMOUNT-5 (PubMed), STEP 2 (PubMed), STEP-HFpEF (PubMed).
Semaglutide diabetes trials: A1C results
| Trial | Dose group | A1C change | Placebo or comparison | Weeks | Who was in it |
|---|---|---|---|---|---|
| SURPASS-2 | Semaglutide 1 mg weekly | 1.86 points lower | semaglutide 1 mg (Ozempic) | 40 | Adults with type 2 diabetes on metformin |
Source: SURPASS-2 (PubMed).
Trials assessing heart, kidney and other outcomes
| Trial | What it measured | Result | Compared with | Length |
|---|---|---|---|---|
| SELECT | Heart attack, stroke or death from heart disease | 6.5% vs 8% 20% lower risk | Placebo | 39.8 months (mean follow-up) |
| SUSTAIN-6 | Heart attack, stroke or death from heart disease | 6.6% vs 8.9% 26% lower risk | Placebo | 104 weeks |
| PIONEER 6 | Heart attack, stroke or death from heart disease | 3.8% vs 4.8% 21% lower risk | Placebo | Not listed |
| SOUL | Heart attack, stroke or death from heart disease | 12% vs 13.8% 14% lower risk | Placebo | 47.5 months (mean follow-up) |
| FLOW | Kidney failure, a large drop in kidney function, or death from kidney or heart causes | 24% lower risk | Placebo | 3.4 years (median follow-up) |
| ESSENCE | MASH resolved without worse scarring | 62.9% vs 34.3% | Placebo | 72 weeks (interim analysis) |
Sources: SELECT (PubMed), SELECT (FDA label (DailyMed)), SUSTAIN-6 (PubMed), PIONEER 6 (PubMed), SOUL (PubMed), FLOW (PubMed), ESSENCE (PubMed).
Safety signals
Sources: PubMed 1 2, FDA label (DailyMed).
The Ozempic label warns about the following serious risks:
- C-cell tumors of the thyroid In rodents it caused thyroid C-cell tumors. Whether it does the same in people is not known. Do not use it if you or someone in your family has a history of medullary thyroid cancer (MTC), or if you have MEN 2.
- Pancreatitis. The medicine can inflame the pancreas. Severe belly pain that continues, sometimes spreading to your back, requires you to stop taking it and get care.
- Worsening diabetic eye disease. A fast drop in blood sugar raises the risk that diabetic eye disease will worsen in people with type 2 diabetes. If you already have this condition, eye checks matter.
- Blood sugar dropping too low. Taking it with insulin or a sulfonylurea raises the risk of low blood sugar, and those doses may need lowering.
- Kidney damage due to fluid loss. Vomiting or diarrhea may cause fluid loss, which can lead to kidney injury. Drink fluids and report heavy fluid loss.
- Severe stomach and gut reactions. Side effects affecting the stomach and gut are common and may be severe. This is not recommended if you have severe gastroparesis.
The FDA label at DailyMed is the source.
The FDA label at DailyMed is the source.
Semaglutide trials now recruiting participants
Look for semaglutide studies recruiting on ClinicalTrials.gov. After you filter by your state, ask the study team about travel and costs.