Semaglutide and cholesterol studies show modest changes in cholesterol, with a larger drop in triglycerides, another type of blood fat. In STEP 1, LDL—the cholesterol linked to artery buildup—fell about 3%, while triglycerides fell about 22% over 68 weeks.
Semaglutide isn't a cholesterol medicine. Those changes don't replace a statin, a medicine prescribed to lower cholesterol. The useful question is whether the actual blood reading reached the goal set by the treating doctor.
Semaglutide and cholesterol: the four lab readings
A lipid panel is a blood test measuring cholesterol and other fats. Its results describe different things, so one improving number doesn't settle the whole picture.
| Reading | What it means |
|---|---|
| Total cholesterol | The overall amount of cholesterol carried in the blood |
| LDL cholesterol | Carries cholesterol that can build up in arteries |
| HDL cholesterol | Helps carry cholesterol back to the liver for removal |
| Triglycerides | A separate blood fat used to store energy |
MedlinePlus explains these readings. A higher HDL reading doesn't cancel out a high LDL reading. Total cholesterol alone also can't show which part changed.
Most U.S. reports use mg/dL, meaning milligrams per deciliter, a measure of concentration in blood. A percentage change describes movement from the starting reading. A 3% drop isn't the same thing as three points lower on the report.
What STEP 1 found at 68 weeks
STEP 1, reported by Wilding and colleagues in the New England Journal of Medicine in 2021, studied 1,961 adults with obesity or overweight. None had diabetes. People were assigned by chance to weekly semaglutide, with a target dose of 2.4 mg, or placebo, an inactive injection.
Both groups received food and activity counseling. Weight loss was the main question. Lipid changes were supportive secondary endpoints, extra measurements beyond that main question.
Table 2 of the published paper reports the following changes. These percentages are converted from its rounded ratios of the final reading to the starting reading.
| Change from starting level at week 68 | Semaglutide | Placebo |
|---|---|---|
| Total cholesterol | About −3% | About 0% |
| LDL | About −3% | About +1% |
| HDL | About +5% | About +1% |
| Triglycerides | About −22% | About −7% |
Minus means a decrease; plus means an increase. These are changes within each group, before subtracting the placebo comparison. The analysis included people who stopped treatment, with estimates for missing readings.
What does a 3% LDL drop look like?
For illustration, a 3% reduction applied to an LDL reading of 130 mg/dL gives:
130 × 0.03 = 3.9 mg/dL lower; 130 − 3.9 = about 126 mg/dL.
The larger triglyceride percentage looks different. A 22% reduction applied to a starting reading of 200 mg/dL gives:
200 × 0.22 = 44 mg/dL lower; 200 − 44 = 156 mg/dL.
Those starting readings are examples, not trial averages or personal forecasts. They show why a noticeable triglyceride change can sit beside a small LDL change.
The distinction matters when someone has lost weight and expects every blood result to follow. An LDL reading can improve and still remain above the doctor's treatment goal.
Why triglycerides can change more with weight loss
Triglycerides are closely tied to how the body handles and stores energy. In STEP 1, the larger triglyceride drop appeared to track the greater weight loss in the semaglutide group.
A later STEP 1 and STEP 4 analysis, published in Diabetes, Obesity and Metabolism in 2023, compared people who lost similar amounts of weight. Within those groups, triglyceride changes were generally similar between semaglutide and placebo. The authors suggested that weight loss explained much of the overall triglyceride difference.
Some cholesterol differences remained within weight-loss groups. That leaves room for effects beyond weight loss, but it doesn't prove a separate drug effect. People weren't assigned how much weight to lose. Other differences between them could influence the findings.
A falling weight and a falling triglyceride reading can therefore fit together without implying that LDL will fall just as far.
Why semaglutide doesn't replace a statin
The LDL change in STEP 1 was modest compared with the reductions expected from statins. The American College of Cardiology's tool based on the 2026 cholesterol guideline lists expected LDL reductions of 30%–49% for moderate-intensity statins. High-intensity statins are expected to lower LDL by at least 50%. Intensity means the treatment's expected cholesterol-lowering strength.
These aren't results from a trial comparing semaglutide with a statin. They show the different scale of LDL lowering each is used for.
The American Heart Association's guideline summary, ties cholesterol goals to the person's heart and blood-vessel risk. It also keeps statins central to treatment when triglycerides remain elevated.
A prescriber may review cholesterol medicines alongside repeat blood tests. Lower weight or better triglycerides alone isn't a reason to stop a prescribed statin.
Are cholesterol changes the same as heart protection?
They are different measurements. A blood test records a risk marker; a heart trial counts events such as heart attacks and strokes.
In SELECT, published in NEJM in 2023, LDL fell 5.25% versus 3.14% with placebo at 104 weeks; the SELECT trial guide explains the separate heart outcome.
About 90% of SELECT participants were already receiving cholesterol-lowering medication. Semaglutide was added to usual care. The broader semaglutide and heart health guide explains whom that evidence describes.
How does tirzepatide compare for cholesterol?
As of October 1, 2026, the day this article was written, an analysis published September 28 in the International Journal of Obesity adds a comparison. It linked STEP 1 and SURMOUNT-1 through their placebo groups, rather than assigning people to one medicine or the other.
The analysis favored tirzepatide for HDL increases and its 15 mg dose for triglyceride reductions. It didn't establish a clear LDL advantage. Tirzepatide's manufacturer funded the study.
Different populations, follow-up lengths and placebo results limit this comparison. It doesn't establish either medicine as a substitute for cholesterol treatment.
Our tirzepatide and cholesterol guide puts that medicine's own trial percentages beside the lab readings they describe.
What belongs in the follow-up conversation
The useful starting point is the actual lipid panel, compared with earlier readings and the goal set by the clinician managing cholesterol. Current medicines, diabetes and a family history of early heart disease help explain that goal.
Three questions keep the review concrete: Which reading changed? Is LDL at its goal? When will the panel be repeated? Weight loss is useful context, but it doesn't answer those questions by itself.
Through Promise, semaglutide is dispensed as a compounded medication, prepared by a pharmacy for an individual prescription. It is different from an FDA-approved product: the formulation offered here is not FDA-approved. As of October 1, 2026, the day this article was written, the FDA explains that it does not review compounded drugs for safety, effectiveness or quality before marketing. The branded trial results don't establish the same lipid changes for Promise's formulation.
A licensed provider may still prescribe a compounded formulation; that decision is between the patient and the doctor. At Promise, a licensed U.S. provider reviews every request, and not everyone qualifies. The prescriber sets the actual dose and considers how treatment fits the person's existing care.
