The appetite signal
The GLP-1 pathway is linked to fullness, slower stomach emptying, and blood-sugar control. Every molecule here acts on it.
Compare · weight-loss medicine
One family of medicine. Three generations.
Semaglutide, Tirzepatide, and Retatrutide all act on the GLP-1 system, but each newer molecule adds another target, and trials tend to report more average weight loss as they do. Here is how they line up on the published data.
Average weight loss in trials
More targets, more weight lost on average.
Average total body-weight reduction at the highest studied dose in each molecule's landmark trial. Different studies, populations, and timeframes, shown for general comparison only.
Semaglutide
GLP-1 · STEP 1, 2.4 mg, 68 weeks
~15%
Tirzepatide
GLP-1 + GIP · SURMOUNT-1, 15 mg, 72 weeks
~21%
Retatrutide
GLP-1 + GIP + glucagon · TRIUMPH-1 Phase 3, 12 mg, 80 weeks
~28%
Your turn
Calculate what you could lose
Enter your current weight and see what each medication's trial average could add up to. An "up to" estimate, never a promise.
Example projection
Retatrutide · trial average
up to 62 lb
from a 220 lb start
Trial average applied to an example, not a prediction
Side by side
The full picture.
| Attribute | Semaglutide | Tirzepatide | Retatrutide |
|---|---|---|---|
| Generation | First | Second | Third |
| Receptor targets | GLP-1 | GLP-1 + GIP | GLP-1 + GIP + glucagon |
| Avg. weight loss in trial | ~15%in STEP 1 | ~21%in SURMOUNT-1 | ~28%in TRIUMPH-1 |
| Landmark trial | STEP 1 (2.4 mg) | SURMOUNT-1 (15 mg) | TRIUMPH-1 (12 mg) |
| Trial length | 68 weeks | 72 weeks | 80 weeks |
| Dosing | Weekly injection | Weekly injection | Weekly injection |
| Also known as | Ozempic / Wegovy | Mounjaro / Zepbound | Exclusively at Deer |
| At Deer from | From $90 | From $230 | From $150 |
| Shop | Shop Semaglutide | Shop Tirzepatide | Shop Retatrutide |
Trial figures are averages from separate published studies, not a prediction of individual results.
How they work
Each target adds another lever.
The second hormone
Tirzepatide adds GIP, another gut hormone involved in how the body handles food energy and insulin response.
The energy lever
Retatrutide adds glucagon activity, which is associated with energy expenditure, on top of the GLP-1 and GIP targets.
Price · vs the alternatives
What the same medicine costs, at your dose.
Pick a medication and set the weekly dose you are on. Prices are live, including any code you have applied, and the comparison is per milligram against the name-brand pen.
1 mg weekly
5mg $90$18 per mg
$72 per month
1 month, 1 weekSave 18% vs Ozempic®10mg $160$16 per mg
$64 per month
2 months, 2 weeksSave 27% vs Ozempic®20mg $280$14 per mg
$56 per month
5 monthsSave 36% vs Ozempic®
The same 4 mg a month, against Ozempic®’s best price
Deer (20mg)$56
Ozempic® with the Savings Card$88
36% less than Ozempic® at their own best discounted price, a saving of $32 every month.
That Ozempic® price is Novo Nordisk Care’s own Savings Card price in Ontario, $88 per 4 mg pen. It is their best discounted price, not the retail one. Ozempic® is a registered trademark of Novo Nordisk, which is not affiliated with Deer. Deer products are sold for research purposes only and are not approved by Health Canada.
Next step
Find the option that fits your plan.
Answer four questions and get matched to one of the three, or browse every weight-loss pen and build your cart.
The figures above are average results from separate published clinical trials, each with different participants, doses, and durations, and are shown only for general comparison. They are not a prediction of your results, and Deer does not claim any product will produce them. Individual results vary. This page is general education, not medical advice, and products are subject to eligibility review.