By Mandy Spence, PA-C | Aura Aesthetics & Wellness, Greenville, SC
Semaglutide or tirzepatide. If you have spent any time researching medical weight loss, you have run into both names, and probably a lot of conflicting opinions about which one “works better.” It is a fair question, and a common one at Aura before anyone ever books a consultation. Here is what the research actually says, in plain language, so you can walk into that conversation already informed.
The real difference is in how each one works
Both medications belong to a class that targets appetite and digestion signals in the body, but they are not built the same way.
Semaglutide is a GLP-1 receptor agonist. It works on one signaling pathway: GLP-1, a hormone your gut naturally releases that slows digestion, supports insulin response, and tells your brain you are full.
Tirzepatide works on two pathways instead of one. It is a dual GIP and GLP-1 receptor agonist, meaning it activates GLP-1 the same way semaglutide does, plus a second hormone pathway called GIP. That second pathway is the leading explanation in the research for why tirzepatide tends to produce a larger average effect. Two signals doing the work instead of one.
That single mechanistic difference is the thread that runs through everything else below.
What the head-to-head trial found
Most of what gets quoted online compares separate studies of each drug, run years apart, on different patient groups. That is a shaky way to compare anything.
The study that actually matters here is SURMOUNT-5, published in the New England Journal of Medicine in May 2025. It put semaglutide and tirzepatide head-to-head, in the same trial, over 72 weeks, in participants without diabetes, each dosed at the highest level they could tolerate.
The result: tirzepatide produced an average weight loss of 20.2%, compared to 13.7% for semaglutide. Participants on tirzepatide were also more likely to reach a major milestone, losing 15% or more of their body weight: 64.6% did, compared to 40.1% on semaglutide.
That is a meaningful gap, and it is a direct comparison, not a cross-study estimate. It is also a trial average, not a personal forecast. Individual response to either medication varies based on your starting point, your metabolism, your other health conditions, and how closely a treatment plan is followed. What SURMOUNT-5 tells you is what tends to happen across a large group of people. What happens for you gets determined with your provider, not from a research summary.
Side effects: similar experience, one notable difference
Because semaglutide and tirzepatide work on overlapping pathways, their side effect profiles look a lot alike. The most common issues with both are gastrointestinal: nausea, vomiting, diarrhea, constipation, and reflux, especially while your dose is being increased. Both also carry the same boxed warning: a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia type 2 rules either one out as an option.
One difference worth knowing. In that same SURMOUNT-5 trial, fewer participants stopped treatment because of GI side effects on tirzepatide (2.7%) than on semaglutide (5.6%). That is a real finding, but it comes from one trial, not a confirmed rule for the entire drug class. It is a data point to bring up with your provider, not a guarantee of how your body will respond.
Who tends to respond to which, according to the research
Here is where it is worth being direct about what the literature can and cannot tell you.
Across both the individual trials and the SURMOUNT-5 head-to-head, tirzepatide shows a consistently larger average effect and, in that one trial, a lower rate of stopping treatment from side effects. That pattern is real and worth knowing.
What it is not is a personal recommendation. Published research describes what happened across groups of trial participants. It does not know your medical history, your current medications, your goals, or how your body has responded to treatments in the past. The research literature also points to something else that matters just as much in practice: for most people, cost and insurance or formulary coverage end up shaping which medication they actually start on at least as much as the physiology does.
Which medication fits you is a conversation, not a lookup. That is exactly what your consultation is for.
A note on access and cost
The landscape around GLP-1 medications, including how they are sourced and what is available, has shifted through 2026 and continues to evolve. What is available to you, how it is dosed, and what it costs depend on your individual situation and current options, and that gets worked out directly with your provider at the time of your visit rather than assumed from anything you read online.
Where to go from here
Semaglutide and tirzepatide are both legitimate, medically supervised tools for weight loss, and the honest answer to “which one is better” is that it depends on you: your health history, your goals, how your body tolerates each option, and what is realistically available to you. That determination happens in a consultation, not a comparison chart.
If you are ready to find out which approach fits your situation, book a consultation with Mandy Spence, PA-C, at Aura Aesthetics & Wellness in Greenville. You will leave with a plan built around your body, not a guess based on a search result.
Book your consultation here or call (864) 640-2379 to schedule.
Frequently Asked Questions
How are semaglutide and tirzepatide actually taken? Both are given as a once-weekly injection. Your provider starts you on a lower dose and increases it gradually over time, based on how you’re tolerating treatment. That titration schedule looks different depending on the product and formulation involved, which is exactly why it gets set with your provider directly rather than estimated here.
How soon will I see results? Weight loss with either medication builds gradually, not overnight. In the research trials, results were measured over many months of consistent treatment while the dose was being adjusted step by step. How quickly you personally notice change depends on your starting point, your dose progression, and how closely a treatment plan is followed, so your provider is the one who can set realistic expectations for your specific plan.
Do the side effects go away? The gastrointestinal side effects most people experience with either medication, things like nausea, reflux, or digestive changes, tend to show up most during dose increases and often ease once your body adjusts to a given dose. Everyone responds differently, and your provider manages the pace of your dose increases around how you’re tolerating treatment, not a fixed schedule.
Will insurance cover this, and what does it cost? Coverage and cost depend on your insurance plan, which category of medication fits your situation, and current availability, and that picture has continued to shift through 2026. Rather than guess at numbers here, your consultation is where your actual options and costs get reviewed against your situation.
What happens during a weight-loss consultation at Aura? You’ll go over your health history, current medications, and goals with Mandy Spence, PA-C, within Aura’s medically supervised weight-loss program. From there, she talks through which option makes sense for you and answers your questions before you decide on anything. Nothing gets started without that conversation first.
Can I switch between semaglutide and tirzepatide later? Some patients do move from one to the other if their first option isn’t giving them the results they want or isn’t well tolerated. Whether that fits your situation, and how a transition would be handled, is a decision made with your provider based on your response to treatment, not something to plan out ahead of time on your own.
Is one of these medications simply “better”? Clinical trials, including a direct head-to-head study, have found tirzepatide associated with a larger average weight loss than semaglutide. But a trial average describes what happened across a large group of people, not what will happen for you. Your health history, other medications, and how your body responds factor into which option actually fits, and that gets worked out in your consultation, not from a comparison like this one.
Mandy Spence, PA-C is the founder of Aura Aesthetics & Wellness in Greenville, SC. A board-certified Physician Assistant with specialized training in medical aesthetics and hormone wellness, she helps patients address visible aging and underlying skin health through advanced laser treatments, personalized aesthetic plans, and a clinical approach that prioritizes safety and long-term results.
