In trials, tirzepatide was given once a week at three target doses: 5, 10 and 15 mg. In people without diabetes, 5 mg cut body weight by 15.0 percent after 72 weeks, 10 mg by 19.5 percent and 15 mg by 20.9 percent. Each of them was reached gradually, starting at 2.5 mg. Below we compare the results of each dose in obesity and in type 2 diabetes, and how the dose affected tolerability.
How is the tirzepatide dose increased?
Tirzepatide is started at 2.5 mg a week for four weeks and then raised by 2.5 mg. The label of the medicine Zepbound allows the next step no more often than every four weeks. The maintenance doses are 5, 10 or 15 mg, and 15 mg is the maximum dose.
In SURMOUNT-1 the whole dose-escalation period lasted 20 weeks. That was the way to 15 mg: 2.5, 5, 7.5, 10, 12.5 and finally 15 mg. The 2.5 mg dose serves only to start treatment, not for longer use. How many vials the whole period uses is calculated in the guide on how long a GLP-1 vial lasts.
What did each dose achieve in people without diabetes?
In people without diabetes every higher dose gave a greater weight loss. SURMOUNT-1 included 2539 adults with an average weight of 104.8 kg and lasted 72 weeks. The results were published in 2022 in the New England Journal of Medicine.
| SURMOUNT-1, after 72 weeks | 5 mg | 10 mg | 15 mg | Placebo |
|---|---|---|---|---|
| Average weight loss | 15.0 percent | 19.5 percent | 20.9 percent | 3.1 percent |
| Loss of at least 5 percent | 85 percent of people | 89 percent of people | 91 percent of people | 35 percent of people |
| Loss of at least 20 percent | not reported | 50 percent of people | 57 percent of people | 3 percent of people |
Moving from 5 to 10 mg gave 4.5 percentage points more. Moving from 10 to 15 mg gave only 1.4 points more. The biggest jump is therefore between the lowest and the middle dose.
What did each dose achieve in people with type 2 diabetes?
In people with diabetes tirzepatide lowered body weight less than in people without it, but still clearly. SURMOUNT-2 included 938 adults with obesity and type 2 diabetes. After 72 weeks body weight fell by 12.8 percent at 10 mg and by 14.7 percent at 15 mg. In the placebo group it was 3.2 percent.
Between 79 and 83 percent of people on tirzepatide lost at least 5 percent of their weight, against 32 percent on placebo. Fewer than 5 percent of participants stopped treatment because of side effects.
Which dose lowered blood sugar the most?
The 15 mg dose lowered blood sugar the most, although already 5 mg worked better than semaglutide 1 mg. This was tested in SURPASS-2, published in 2021 in the New England Journal of Medicine. It included 1879 people with type 2 diabetes and lasted 40 weeks.
| SURPASS-2, after 40 weeks | Tirzepatide 5 mg | Tirzepatide 10 mg | Tirzepatide 15 mg | Semaglutide 1 mg |
|---|---|---|---|---|
| HbA1c fall | 2.01 points | 2.24 points | 2.30 points | 1.86 points |
| Extra weight loss compared with semaglutide | 1.9 kg | 3.6 kg | 5.5 kg | reference point |
Glycated haemoglobin is the average blood sugar over recent months; at the start it averaged 8.28 percent. Every tirzepatide dose did better than semaglutide 1 mg, both in blood sugar and in body weight. More results from the whole programme are in the guide on tirzepatide and the SURPASS trials.
From which dose does tirzepatide outperform semaglutide 2.4 mg?
In people without diabetes, the 10 and 15 mg doses of tirzepatide gave an advantage over semaglutide 2.4 mg. The 5 mg dose pointed the same way, but the difference was not statistically certain. These conclusions come from an indirect comparison of STEP 1 and SURMOUNT-1, published on 28 September 2026 in the International Journal of Obesity.
An indirect comparison sets two separate trials side by side through their shared placebo group. It does not replace a direct trial, but it allows the result to be split by dose. The work was prepared by researchers linked to the maker of tirzepatide, which is worth keeping in mind.
| Difference compared with semaglutide 2.4 mg | Tirzepatide 5 mg | Tirzepatide 10 mg | Tirzepatide 15 mg |
|---|---|---|---|
| Body weight | no certain difference | 5.10 kg less | 6.50 kg less |
| Waist circumference | no certain difference | 5.25 cm less | 5.75 cm less |
| Diastolic blood pressure | 1.90 mm Hg lower | 2.40 mm Hg lower | 1.30 mm Hg lower |
| HDL cholesterol | 3.80 percent higher | 5.40 percent higher | 5.00 percent higher |
In people with a body composition measurement, 15 mg gave a body fat share 3.5 percentage points lower than semaglutide. The share of lean mass was 3.4 points higher. According to the authors, the side effect profile of both molecules was similar.
How did the dose affect tolerability?
The most common side effects concerned the digestive tract and appeared mainly during dose escalation. In SURMOUNT-1 they were mostly mild or moderate. The share of people stopping treatment because of them was low at every dose.
| Trial | 5 mg | 10 mg | 15 mg | Comparison |
|---|---|---|---|---|
| SURMOUNT-1: stopped because of side effects | 4.3 percent | 7.1 percent | 6.2 percent | 2.6 percent on placebo |
| SURPASS-2: nausea | 17 to 22 percent | 18 percent on semaglutide 1 mg | ||
| SURPASS-2: diarrhoea | 13 to 16 percent | 12 percent on semaglutide 1 mg | ||
Nausea on tirzepatide was therefore about as frequent as on semaglutide 1 mg. Blood sugar below 54 mg/dl was reported in SURPASS-2 by 0.2 to 1.7 percent of people on tirzepatide and 0.4 percent on semaglutide.
How much does a week cost at each dose?
The cost of a week rises with the dose, because the shop price works out per milligram. A 20 mg vial of tirzepatide costs 200 EUR, so 10 EUR per milligram. The 40 mg pen costs 350 EUR, so 8.75 EUR per milligram.
| Weekly dose | 20 mg vial, cost per week | 40 mg pen, cost per week | How many weeks a 40 mg pen lasts |
|---|---|---|---|
| 2.5 mg | 25 EUR | 21.88 EUR | 16 weeks |
| 5 mg | 50 EUR | 43.75 EUR | 8 weeks |
| 10 mg | 100 EUR | 87.50 EUR | 4 weeks |
| 15 mg | 150 EUR | 131.25 EUR | almost 3 weeks |
At every dose the pen works out 12.5 percent cheaper than the vial. The differences in preparation and storage are described in the guide peptide pen vs powder vial.
Where to buy tirzepatide?
In the shop, tirzepatide comes in three versions from three manufacturers. Tirzepatide 20 mg Bio-Peptide costs 200 EUR and is in stock. Tirzepatide 20 mg Genheal costs 200 EUR and is available on backorder. Tirzepatide 40 mg Nouveaux in a pen costs 350 EUR and is in stock.
The doses described above come from the medicine label and clinical trials. They are not a recommendation for research material, and choosing a dose for a person is a matter for a doctor. The course of weight loss over the months is described in the guide on tirzepatide results. All versions and the price per milligram are on the tirzepatide page.
Frequently asked questions
What dose is tirzepatide started at?
At 2.5 mg once a week for four weeks. The dose is then raised by 2.5 mg no more often than every four weeks, to 5, 10 or 15 mg.
Which tirzepatide dose gives the greatest weight loss?
The 15 mg dose, which cut body weight by 20.9 percent after 72 weeks in SURMOUNT-1. The 10 mg dose gave 19.5 percent and 5 mg gave 15.0 percent.
Is 5 mg of tirzepatide enough to lose weight?
In SURMOUNT-1 the 5 mg dose gave an average weight loss of 15.0 percent after 72 weeks. At that dose 85 percent of people lost at least 5 percent of their weight.
Does tirzepatide work better than semaglutide in diabetes?
In SURPASS-2 every tirzepatide dose lowered blood sugar more than semaglutide 1 mg. At 15 mg the weight loss was 5.5 kg greater.
How much does a week of tirzepatide cost at 10 mg?
From a 20 mg vial at 200 EUR it comes to 100 EUR a week, and from a 40 mg pen at 350 EUR to 87.50 EUR a week.
Sources
- Jastreboff AM, Aronne LJ, Ahmad NN et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine, 2022, 387(3): 205-216. https://doi.org/10.1056/NEJMoa2206038
- Garvey WT, Frias JP, Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2). The Lancet, 2023, 402(10402): 613-626. https://doi.org/10.1016/S0140-6736(23)01200-X
- Frías JP, Davies MJ, Rosenstock J et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. New England Journal of Medicine, 2021, 385(6): 503-515. https://doi.org/10.1056/NEJMoa2107519
- Ciudin A, Johansson E, Zimner-Rapuch S et al. Indirect comparative efficacy and safety of tirzepatide vs semaglutide for the treatment of obesity or overweight in patients without type 2 diabetes. International Journal of Obesity, 2026. https://doi.org/10.1038/s41366-026-02229-6
- U.S. Food and Drug Administration. Zepbound (tirzepatide) injection, prescribing information, 217806s013. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/217806s013lbl.pdf