GLP-1 Drugs and Cholesterol: What Happens to LDL, HDL and Triglycerides

GLP-1 drugs lower triglycerides clearly and LDL cholesterol only a little. In the trials printed on their FDA labels, Wegovy (semaglutide) and Zepbound (tirzepatide) cut triglycerides by about 14% to 25% more than placebo, raised HDL cholesterol by a few percent, and lowered LDL, the “bad” cholesterol, by at most about 7%.^[1][2] That makes them useful for the fat-related part of a lipid panel but no substitute for a statin, which is the drug designed to bring LDL down.

What happens to each number on a lipid panel

Relative differences from placebo at week 68 (Wegovy, STEP 1 to 3) and week 72 (Zepbound, SURMOUNT-1 and -2). None of these lipid results was part of the trials’ formal statistical testing.^[1][2]

Semaglutide: the STEP trials and SELECT

The Wegovy label reports three 68-week trials side by side: STEP 1 in adults with obesity or overweight, STEP 2 in adults with type 2 diabetes, and STEP 3, where everyone also had intensive lifestyle therapy. Against placebo, triglycerides fell by 15.8%, 13.9% and 17.0%. LDL fell by 3.8% in STEP 1 and 7.1% in STEP 3, and was essentially unchanged in STEP 2 (0.4% higher). HDL rose by 1.5% to 3.8%.^[1]

SELECT, the heart outcomes trial behind Wegovy’s cardiovascular indication, enrolled people with established heart disease, and their LDL was already low at the start, around 78.5 mg/dL on average. Over two years, LDL was 2.2% lower than on placebo and triglycerides 15.6% lower.^[1] Semaglutide still cut heart attacks, strokes and cardiovascular deaths in that trial, with a hazard ratio of 0.80.^[1] The lipid changes were small, and the trial was not built to show which of the drug’s effects produced the benefit. The results are at SELECT.

A 2025 meta-analysis of four trials of semaglutide 2.4 mg in adults without diabetes put the changes in mg/dL: triglycerides about 15 mg/dL lower, LDL about 6 mg/dL lower, total cholesterol about 6 mg/dL lower and HDL about 2 mg/dL higher.^[3] For someone with an LDL of 130, 6 mg/dL is a little under 5%.

Tirzepatide: SURMOUNT-1 and SURMOUNT-2

The Zepbound label gives results by dose. In SURMOUNT-1, in adults without diabetes, triglycerides fell 16.5%, 19.3% and 24.9% more than placebo on 5, 10 and 15 mg. LDL fell 2.9%, 4.0% and 5.5%. HDL rose 7.7% to 9.9%, more than with semaglutide. Non-HDL cholesterol, which counts all the particles that can build up in arteries, fell 5.8% to 9.6%.^[2] SURMOUNT-2, in adults with type 2 diabetes, showed the same pattern, with triglycerides about 25% lower on both doses.^[2]

Meta-analyses that pooled tirzepatide trials found the same direction for every lipid and a dose response, with higher doses moving the numbers further.^[4][6] Across seven trials, total cholesterol fell by a median of 3.8% on 5 mg and 5.9% on 15 mg.^[4]

Why LDL barely moves

The trials show the gap but were not designed to explain it. A meta-analysis of placebo-controlled GLP-1 trials found a modest LDL drop of about 3 mg/dL, and found that the amount of weight lost did not predict how much LDL changed.^[5] So losing more weight on the drug does not reliably bring LDL further down.

In one of the label trials, STEP 2 in people with type 2 diabetes, LDL did not fall at all on semaglutide.^[1] If your LDL is high before you start, or stays high on the drug, ask your clinician whether your target calls for a statin regardless of the weight you lose.

Other GLP-1 drugs and newer agents

The effect is smaller across the GLP-1 class as a whole. The meta-analysis that pooled placebo-controlled trials across the GLP-1 class found LDL about 3 mg/dL lower and total cholesterol about 7 mg/dL lower, with no significant change in triglycerides or HDL once all the drugs were combined.^[5] A separate meta-analysis of 29 trials in adults with overweight or obesity and without diabetes ranked the drugs on lipids and found retatrutide, a triple agonist still in trials, and semaglutide the most effective at improving the lipid profile.^[7] The pooled class result is weaker on triglycerides and HDL than the semaglutide and tirzepatide label trials, and LDL changes little in all of them.

Lipid numbers also differ by who is being treated. In both drug programs, the trials in type 2 diabetes started with lower LDL than the trials in obesity alone: about 90 mg/dL in STEP 2 against 110 mg/dL in STEP 1, and about 86 to 91 mg/dL in SURMOUNT-2 against about 109 mg/dL in SURMOUNT-1.^[1][2] The diabetes trials also showed the smallest LDL changes.

What this means if you have high cholesterol

• High triglycerides: a GLP-1 drug is likely to help, often by 15% to 25% compared with placebo.^[1][2]
• High LDL: expect little change from the drug itself. LDL is the number most tied to statin treatment, and none of these labels lists cholesterol lowering as an approved use.
• Already on a statin: keep taking it. In SURPASS-CVOT, the tirzepatide heart trial, 86% of participants were on a statin at the start;^[8] how the two drugs fit together is in statins and a GLP-1.
• Cholesterol deposits on the eyelids: whether weight loss shrinks xanthelasma is covered in xanthelasma and weight loss.

Which drug moves the lipid panel more: tirzepatide raised HDL and lowered triglycerides somewhat more than semaglutide did in their separate placebo-controlled trials, and lost more weight in the one head-to-head trial, as explained in how Zepbound works. No trial has compared their lipid effects directly with lipids as the main goal. Tirzepatide’s heart results in type 2 diabetes are covered in Mounjaro heart protection and SURPASS-CVOT.