Three drugs come up most often when people talk about GLP-1 weight loss: Ozempic, Mounjaro, and Zepbound. They’re related but not the same, and the differences matter for understanding what to expect.
Here’s a straightforward comparison without the marketing language.
The Basic Difference
Ozempic and Wegovy contain semaglutide. Semaglutide activates one receptor — the GLP-1 receptor. This reduces appetite, slows gastric emptying, and helps regulate blood sugar. Ozempic is approved for type 2 diabetes. Wegovy is approved specifically for weight loss at higher doses.
Mounjaro and Zepbound contain tirzepatide. Tirzepatide activates two receptors — both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). The dual activation produces stronger appetite suppression and greater weight loss in clinical trials than single-receptor drugs. Mounjaro is approved for type 2 diabetes. Zepbound is approved for weight loss.
The practical version: tirzepatide (Mounjaro/Zepbound) produces more weight loss on average than semaglutide (Ozempic/Wegovy). It also costs more and has its own side effect profile.
Weight Loss Results Compared
The clinical trial data gives us the clearest comparison, though the trials weren’t head-to-head — they used different study populations and protocols.
Semaglutide (Wegovy) — STEP 1 trial: Average weight loss of about 14.9 percent of body weight over 68 weeks. Roughly 1 in 3 participants lost 20 percent or more.
Tirzepatide (Zepbound) — SURMOUNT-1 trial: Average weight loss of about 20.9 percent of body weight at the highest dose over 72 weeks. Roughly 1 in 2 participants lost 20 percent or more.
These numbers are averages. Individual results vary considerably based on diet, exercise, dose, and individual response. But the trend is consistent: tirzepatide produces greater average weight loss than semaglutide.
Side Effect Differences
Both classes cause similar GI side effects — nausea, vomiting, diarrhea, constipation — because both slow gastric emptying and affect gut hormone signaling. The frequency and severity are similar between the two.
Some people find one tolerable and the other not — individual response to side effects varies and doesn’t always predict which drug will work better for weight loss. If semaglutide causes intolerable nausea, tirzepatide might be better tolerated, and vice versa. This isn’t guaranteed but it’s worth knowing switching is an option.
Cost Comparison
Ozempic without insurance: $900 to $1,000 per month
Wegovy without insurance: $1,300 to $1,600 per month
Mounjaro without insurance: $1,000 to $1,200 per month
Zepbound without insurance: $550 to $650 per month (lower than Mounjaro for the same drug, reflecting its weight-loss-specific approval and manufacturer pricing decisions)
Compounded semaglutide through telehealth: $200 to $400 per month
Compounded tirzepatide through telehealth: $250 to $500 per month
Compounded versions of both drugs are available through licensed telehealth providers and licensed compounding pharmacies — same active ingredients, substantially lower cost.
Which One Is Right?
If you want maximum average weight loss and cost is not the primary concern: tirzepatide (Mounjaro/Zepbound) has better average results in trial data.
If you want the drug with the longest clinical track record: semaglutide has been in widespread use longer and has more real-world data.
If insurance is covering your medication: let your insurance formulary and your provider’s clinical judgment guide the choice. Not all insurance covers both drugs equally.
If you’re using telehealth and paying out of pocket: both are available as compounded versions at comparable price points. Starting with semaglutide is the more conservative choice. Switching to tirzepatide if results are slower than expected is a reasonable escalation path.
I use semaglutide through ShedRX. I haven’t switched because I’ve had consistent results and I’m not in a situation where maximizing the rate of loss is the priority over sustainability. That’s a personal calculation.
The GLP-1 program I use is here.
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