Women's Health

Wegovy vs Zepbound for Women: The Trial-by-Trial Comparison (2026)

By the US Health Digest editorial team · Updated July 21, 2026

In the only head-to-head trial published to date, tirzepatide (Zepbound) produced greater average weight loss than semaglutide (Wegovy) over 72 weeks. Both drugs are well studied in women, both carry predominantly gastrointestinal side effects that usually fade, and both stop working if you stop taking them. The right choice depends on your health history, your insurance coverage, and a conversation with a prescriber — not on averages alone.

What each drug is

Wegovy is semaglutide, a GLP-1 receptor agonist, given as a once-weekly injection. Zepbound is tirzepatide, which activates two hormone receptors — GIP and GLP-1 — also as a once-weekly injection. Both are branded medications approved for chronic weight management, and both work by reducing appetite and slowing how quickly the stomach empties.

For women, the trial evidence is unusually relevant: in semaglutide's pivotal trial, roughly three-quarters of participants were women, so the headline results largely describe outcomes in women rather than being extrapolated to them.

What the trials found

Semaglutide: the STEP 1 trial

In STEP 1, published in the New England Journal of Medicine, adults with overweight or obesity (without diabetes) taking semaglutide 2.4 mg weekly lost an average of 14.9% of body weight over 68 weeks, compared with 2.4% on placebo — both groups alongside lifestyle intervention. About 4.5% of semaglutide participants discontinued due to gastrointestinal events, versus 0.8% on placebo. We break the female-specific data down further in our guide to semaglutide results in women.

Tirzepatide: the SURMOUNT-1 trial

In SURMOUNT-1, adults taking tirzepatide lost up to 20.9% of body weight on average at the highest dose (15 mg) over 72 weeks. Lower doses produced smaller but still substantial average losses. On paper, that number is larger than STEP 1's — but comparing across separate trials with different populations and durations is unreliable, which is why the next trial matters most.

The head-to-head: SURMOUNT-5

In 2025, NEJM published SURMOUNT-5, a randomized trial that directly compared tirzepatide with semaglutide in adults with obesity. The result: tirzepatide produced greater average weight loss than semaglutide over 72 weeks. That settles the cross-trial guessing — on average, at trial doses, tirzepatide came out ahead. Averages are not individual guarantees, though; in every trial, individual responses ranged widely in both directions.

What happens if you stop

SURMOUNT-4 tested exactly this: participants who stopped tirzepatide after an initial treatment period regained a substantial portion of the weight they had lost, while those who continued kept losing. The practical takeaway for either drug is the same — these are treatments for a chronic condition, not a short course, and any plan should account for long-term use or a supervised off-ramp.

Side effects: broadly similar, mostly GI

Both medications share the same dominant side-effect profile: nausea, diarrhea, constipation, and vomiting, most common during dose escalation and typically transient. In STEP 1, gastrointestinal events led 4.5% of semaglutide participants to stop treatment, versus 0.8% on placebo. Tirzepatide's profile in its trials was broadly similar — predominantly GI, mostly mild to moderate. Neither drug is a casual undertaking, and a prescriber should review your full history, including gallbladder disease, pancreatitis risk, and thyroid history, before starting either. Our GLP-1 FAQ for women covers the questions we hear most.

Pregnancy: a hard stop

Neither semaglutide nor tirzepatide should be used during pregnancy or while trying to conceive. This is not a gray area. Any legitimate prescriber will screen for pregnancy and contraception plans before writing either prescription — if a program doesn't ask, treat that as a red flag.

Cost: the real-world tiebreaker

Tirzepatide typically costs more than semaglutide. Both are branded drugs without generic equivalents, and out-of-pocket prices vary widely with insurance; both manufacturers run direct-pay programs that can narrow the gap for eligible patients. For many women, coverage — not the head-to-head result — ends up deciding which drug is realistic. If you're weighing cheaper compounded alternatives, read our compounded vs branded GLP-1 comparison first, because the trade-offs are not trivial.

How to decide with a clinician

A reasonable framework: if both drugs are covered and there's no history that favors one, the head-to-head evidence supports tirzepatide for average weight loss. If coverage or cost favors semaglutide, STEP 1's results show it remains a strongly effective option — 14.9% average loss is a clinically meaningful outcome by any standard. Whichever direction you lean, the decision should be made with a clinician who reviews your medications, conditions, and reproductive plans, and who commits to monitoring you over time. If you're comparing prescriber options, our review of GLP-1 telehealth programs for women outlines what a responsible program looks like.