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Key Takeaways
- Semaglutide works on one gut hormone receptor (GLP-1). Tirzepatide works on two (GLP-1 and GIP).
- In their main trials, semaglutide averaged 14.9% weight loss over 68 weeks. Tirzepatide averaged 15.0% to 20.9% over 72 weeks, depending on dose.
- Both drugs cause mostly stomach and gut side effects, and in both trials most of it was mild to moderate.
- First-time patients can start GobyMeds with a three-month bundle: $299 for compounded semaglutide or $399 for compounded tirzepatide, which works out to $99 and $133 a month. Neither compounded version is FDA-approved.
If you’ve decided a GLP-1 is worth a conversation with a provider, the next question comes fast. Which one?
GobyMeds offers compounded versions of both. So the GobyMeds semaglutide vs tirzepatide decision isn’t really about the platform. It’s about the two molecules, what the research shows for each, and what you’re willing to pay and put up with. Here’s what the evidence says.
How Does Tirzepatide Work vs Semaglutide?
Semaglutide activates the GLP-1 receptor. Tirzepatide activates the GLP-1 receptor and the GIP receptor. That’s the whole mechanical difference.
GLP-1 is a gut hormone that helps regulate appetite and how much you eat. The FDA label for Wegovy, the brand-name semaglutide for weight management, describes semaglutide as a GLP-1 analogue that acts on brain regions involved in food intake.
The Zepbound label, the brand-name tirzepatide, says the same about GLP-1 and adds that nonclinical studies suggest GIP “may further contribute to the regulation of food intake.” Note the word “may.” The second receptor is the leading explanation for the bigger average weight loss, not a proven one.
Which Is Better for Weight Loss, Semaglutide or Tirzepatide?
On average, tirzepatide produced more weight loss in the trials. Both produced a lot.
The STEP 1 trial (NEJM, 2021) gave 1,961 adults without diabetes either semaglutide 2.4 mg weekly or placebo for 68 weeks, alongside a lifestyle program. The semaglutide group lost 14.9% of body weight on average. The placebo group lost 2.4%. About half the semaglutide group lost 15% or more.
The SURMOUNT-1 trial (NEJM, 2022) gave 2,539 adults without diabetes one of three tirzepatide doses or placebo for 72 weeks. Average weight loss was 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, against 3.1% on placebo.
Those are separate trials, so they don’t compare the drugs directly. SURMOUNT-5 (NEJM, 2025) did. It put 751 adults with obesity on the highest dose each person tolerated of one drug or the other for 72 weeks. Tirzepatide averaged 20.2% weight loss. Semaglutide averaged 13.7%.
Two caveats. SURMOUNT-5 was open-label and funded by Eli Lilly, which makes tirzepatide. And all three trials tested the brand-name drugs, not compounded versions.
For a 220-pound man, 14.9% is about 33 pounds and 20.2% is about 44 pounds. Those are group averages, not a forecast for you.
Does Tirzepatide Have Fewer Side Effects Than Semaglutide?
Not clearly. Both labels list the same core problems: nausea, diarrhea, vomiting, constipation and stomach pain. In both trials, most of it was mild to moderate. In SURMOUNT-1 it came mainly while the dose was being raised; in STEP 1 it was typically short-lived and faded with time.
The label numbers look different on paper. In the Wegovy trials, 44% of patients reported nausea and 24% reported vomiting. In the Zepbound trials, nausea ran 25% to 29% and vomiting 8% to 13%, depending on dose.
Don’t read too much into that. Both labels warn that side effect rates from one drug’s trials can’t be directly compared to another drug’s trials. The ways people drop out tell a similar story. On the Wegovy label, 4.3% of patients stopped because of gut side effects, against 0.7% on placebo. On the Zepbound label it was 1.9% to 4.3% depending on dose, against 0.5%.
The serious warnings are shared too. Both labels carry a boxed warning about thyroid C-cell tumors seen in rodents, and both are off the table if you or a family member has had medullary thyroid carcinoma or MEN 2. Both list pancreatitis and gallbladder disease. Bring your full history to the intake.
How Much Do GobyMeds Semaglutide and Tirzepatide Cost?
As of September 2026, first-time patients can start GobyMeds with a three-month bundle: $299 for compounded semaglutide or $399 for compounded tirzepatide, which works out to $99 and $133 a month. A single month is listed from $169 for semaglutide and from $299 for tirzepatide, and higher doses cost more.
GobyMeds says the starter bundles include medication, shipping, the consultation and an injection kit. Brand-name Zepbound is listed at $1,399 a month and Wegovy at $1,695 a month. There’s no subscription, and prescriptions are final sale. Confirm what your prescribed plan costs before you pay.
One thing to be clear on. Compounded GLP-1s are not FDA-approved, and the FDA says salt forms such as semaglutide sodium and semaglutide acetate are different active ingredients from the ones in the approved drugs. Shipping, pharmacy and the rest of the fine print are covered in our GobyMeds review for men over 50.
Should a Man Over 50 Take Semaglutide or Tirzepatide?
That’s a call for you and the prescriber, not a blog post. But here’s how I’d frame the conversation.
If the goal is the most weight loss the research supports, tirzepatide has the stronger head-to-head data. If you want the lower starting price, semaglutide makes a lot of sense. It’s also the one whose brand-name label covers cutting the risk of heart attack, stroke and cardiovascular death in adults with established cardiovascular disease who also have obesity or overweight, which matters to plenty of men over 50.
Know who was in the trials, too. The Wegovy label reports a mean trial age of 48 and 71% women. The Zepbound pool averaged 47 years old and 37% men. The averages above weren’t built on men in their fifties and sixties, so treat them as a guide.
Whichever you pick, the dose schedule belongs to the prescriber. Both drugs start low and step up over months, and the side effects track those steps.
And after 50, the scale isn’t the only number that matters. Both labels say the drug takes off more fat than lean mass. That still means some of what you lose is lean mass. The medication makes eating less easier. Protein and strength training help decide how much of what you lose is fat. Our guide to GLP-1 for men over 50 covers who qualifies.
When you’re ready to get a provider’s opinion on which one fits your history, you can start a GobyMeds intake here.
Related Reading
- Compounded vs brand-name GLP-1: every trial number in this post came from Wegovy and Zepbound, so read this before assuming a compounded dose behaves the same way.
- How to keep muscle on a GLP-1 after 50: a 20% drop in body weight only helps if most of it is fat, and this covers what the evidence says about keeping it that way.
