SEMAGLUTIDE / THE MAIN STUDIES
What Did Semaglutide Studies Find in People?
You’ll learn who was studied and what changed, so an average won’t look like your result.
Which Semaglutide results matter most to you?
Novo Nordisk made semaglutide to outlast the gut hormone behind its effects. By 2025, large studies had looked at weight, kidneys, the liver, and heart health. In one liver study, swelling eased in about 63 out of 100 people taking it and about 34 out of 100 taking placebo; a weight study found an average near 15%. For my own family, I’d add that a 2025 comparison gave tirzepatide the larger average loss, so semaglutide didn’t lead on every count.
What did the large liver study find?
A phase-3 liver study enrolled 1,197 adults with MASH; the first report covered 800. MASH means liver fat is causing swelling and harm. Doctors checked a small piece of each person’s liver, called a biopsy. People got a 2.4 mg weekly shot or a placebo, a shot without semaglutide.
Swelling ended without worse scars in 62.9% on semaglutide and 34.3% on placebo. Scars eased without worse swelling in 36.8% on semaglutide and 22.4% on placebo [1]. Researchers compared each gap with the random swing expected in a study this size. They weren’t small enough to blame on that swing. The liver findings led to the 2025 MASH approval, but they can’t predict your result.
How much Semaglutide weight loss did studies find?
STEP 1 was a weight study of adults without diabetes. They took a 2.4 mg weekly shot or a placebo, a shot with no semaglutide. By week 68, average weight changed -14.9% with semaglutide and -2.4% with placebo, a difference of roughly 12.4 points [2]. STEP 5 followed weight longer and found the loss could last two years [13]; teens also lost more weight for their height than those on placebo [14], though neither result promises yours.
STEP 4 found more loss among people who stayed on semaglutide. When people changed to placebo, their weight began returning [15]. After STEP 1 ended, average regain was roughly 11.6 points of body weight within one year, and other health gains faded too [16]. Here’s the hard part for you: stopping often means some weight returns. Your own course may look different.
What happened to people’s hearts and kidneys?
SUSTAIN-6 followed 3,297 people with type 2 diabetes who faced heart danger. Semaglutide brought fewer heart deaths, nonfatal heart attacks, and nonfatal strokes [3]. A 95% check tests how much a result may shift by chance, and it’s clear this one favored the drug. Eye trouble from diabetes rose instead. Its 95% check backed the warning, but it couldn’t give your personal chance. In another study, 17,604 adults without diabetes had 20% fewer major heart events with 2.4 mg. That result’s 95% check also favored semaglutide [4].
A later review found the heart gain didn’t depend on starting blood sugar [17]. In a kidney study, 3,533 people had kidney disease and type 2 diabetes. Major kidney events dropped by 24% with a 1.0 mg amount. The study counted kidney failure, kidney- or heart-related death, and a 50% loss of kidney work. Its 95% check favored semaglutide [5]. The eye result went the other way, so it’s worth discussing with your doctor.
What did Semaglutide vs tirzepatide find about weight?
SURMOUNT-5 followed 751 adults with obesity. Semaglutide copies GLP-1, one gut hormone, while tirzepatide copies that hormone plus a second one that also affects blood sugar and hunger; by week 72, average loss was -20.2% with tirzepatide and -13.7% with semaglutide [18]. Semaglutide didn’t lead in that study.
SURPASS-2 involved people with type 2 diabetes. Compared with 1.0 mg semaglutide, tirzepatide brought larger drops in weight and long-term blood sugar [19]. Semaglutide has the longer record of heart studies. Your choice can’t rest on pounds alone, and this page can’t make it for you.
Why doesn’t compounded semaglutide have the same proof?
From roughly 2022 to early 2025, federal shortage rules let pharmacies compound semaglutide. The FDA reported dose mistakes, hospital stays, and some products made with unchecked drug ingredients. In early 2025, officials declared the shortage resolved and cut back that broad permission. You can’t assume every mixed product was alike.
All studies on this page relied on the approved factory product. Compounded semaglutide wasn’t tested there, so the same proof doesn’t carry over. No seller is ranked on this page. Your safety still depends on what was actually prepared.