Blog · Weight Loss
A semaglutide weight loss timeline helps you set fair expectations: when the scale usually starts to move, when results build, and when they level off. The most reliable timeline comes from the large trials behind the medicine, not from before-and-after posts. Below, Dr. Melanie Espinet walks through what the STEP 1 trial of semaglutide 2.4 mg showed over 68 weeks, and what the SURMOUNT-1 trial showed for tirzepatide. If you’re considering treatment, see semaglutide weight loss in Lutz and Tampa for how care works at MeliOra.
STEP 1 enrolled 1,961 adults without diabetes who had a BMI of 30 or higher, or 27 or higher with a weight-related health condition. Everyone got counseling for a reduced-calorie diet, about 500 fewer calories a day, and for at least 150 minutes of activity a week. The semaglutide dose started low and went up every four weeks for 16 weeks. From week 17, the target was the full 2.4 mg dose, held for the rest of the trial.
The STEP 1 paper reports exact averages at the end of the trial. Between visits, the trial’s published weight curve shows the shape of the journey. We describe that shape rather than invent monthly percentages the trial never reported:
| Time on semaglutide | What STEP 1 showed |
|---|---|
| Weeks 1 to 4 (month 1) | The lowest starting dose. Average weight was already lower at the first check, week 4. |
| Weeks 5 to 16 (months 2 to 4) | The dose went up every four weeks. Weight came down steadily through this whole stretch. |
| Weeks 17 to 28 (months 5 to 7) | The full 2.4 mg dose. Weight kept falling, a little more slowly than before. |
| Weeks 29 to 52 (months 8 to 12) | Loss continued, but each month added less than the month before. |
| Weeks 53 to 68 (months 13 to 16) | The average leveled off, with its lowest point around week 60. At week 68, average loss was 14.9 percent on semaglutide and 2.4 percent on placebo. |
Two things stand out. Weight loss was already under way during the dose-increase months, before anyone reached the full dose. And weight loss naturally slows, then levels off. That leveling off is expected, and our guide to the semaglutide plateau explains why it happens and what can help.
The first dose is the lowest. The prescribing information explains that the dose rises in steps to lower the risk of stomach side effects, so month 1 is mostly about letting your body adjust. Even so, in STEP 1 average weight was already a little lower by week 4.
In STEP 1, the dose went up every four weeks, and weight came down steadily the whole time. The semaglutide label notes that stomach side effects were reported most often during these dose increases. In STEP 1, nausea and diarrhea were the most common, and they were usually mild to moderate and eased with time. If a step is hard to tolerate, the label lets the prescriber wait four more weeks before the next increase, which can stretch your timeline a little. Our guide to semaglutide side effects covers how to manage them.
From week 17, the target was the full 2.4 mg dose. Weight kept falling through this stretch, but each month added a little less than the one before. Trial participants kept getting diet and activity counseling the whole time, and your habits matter here too: protein at each meal, regular movement, and strength training to protect muscle. Our guides to what to eat on semaglutide and muscle loss on GLP-1 medicine go deeper.
In STEP 1, average weight reached its lowest point around week 60 and stayed near there to week 68. At week 68, the average loss was 14.9 percent of body weight, or 15.3 kilograms, about 34 pounds. Researchers describe a plateau like this as the body moving from losing to holding steady, ideally the start of long-term maintenance.
In STEP 1, people on semaglutide lost an average of 15.3 kilograms, about 34 pounds, over 68 weeks. Spread evenly, that is about half a pound a week, but real loss came faster in the early months and slower later. The placebo group, who got the same diet and activity counseling, lost an average of 2.6 kilograms, about 6 pounds.
Percentages travel better than pounds, because they scale with your starting weight. Here is what the STEP 1 average would mean at a few starting weights. This is simple arithmetic on an average, not a forecast for you.
| Starting weight | The STEP 1 average (14.9 percent) of that weight |
|---|---|
| 180 pounds | About 27 pounds |
| 200 pounds | About 30 pounds |
| 250 pounds | About 37 pounds |
| 300 pounds | About 45 pounds |
Averages hide a wide spread. In STEP 1, 86.4 percent of people on semaglutide lost at least 5 percent of their weight, 69.1 percent lost at least 10 percent, and 50.5 percent lost at least 15 percent. That also means about 1 in 7 lost less than 5 percent. The semaglutide group also saw greater improvements in heart and metabolic risk factors, and in self-reported physical function, than the placebo group.
SURMOUNT-1 tested weekly tirzepatide in 2,539 adults without diabetes, with similar BMI entry rules and the same kind of lifestyle counseling. People were assigned to 5 mg, 10 mg or 15 mg, or placebo, for 72 weeks. The dose was raised over a period of up to 20 weeks, then held at the assigned dose.
| Tirzepatide dose in SURMOUNT-1 | Average weight loss at week 72 |
|---|---|
| 5 mg | 15.0 percent |
| 10 mg | 19.5 percent |
| 15 mg | 20.9 percent |
| Placebo | 3.1 percent |
The share who lost at least 5 percent was 85, 89 and 91 percent on the three doses. On 10 mg and 15 mg, half or more lost at least 20 percent (50 and 57 percent). Stomach side effects were the most common, mostly mild to moderate, and happened mainly while the dose was going up.
The published SURMOUNT-1 weight curve has the same shape as STEP 1: steady loss during the dose increases, slower loss after, and a flattening toward the end. A later analysis of SURMOUNT-1 looked closely at that shape. It included only people who kept taking tirzepatide and lost at least 5 percent, so it describes people who responded, not everyone.
In that group, weight loss was greatest in the first 24 weeks: 13.3 to 14.5 percent on average by week 24, depending on starting BMI. Between week 24 and week 72 they lost another 4.6 to 9.7 percent, with people who started at a higher BMI losing more in that later stretch. The typical (median) time to reach a plateau was about 24 to 36 weeks.
STEP 1 and SURMOUNT-1 were separate trials, with different people, lengths and doses, so their numbers can’t be lined up as a fair contest. For how the two medicines compare head to head, see semaglutide vs. tirzepatide, and for care details see tirzepatide weight loss in Lutz.
Trial averages are a guide, not a promise. A few factors the research points to:
None of these factors is a verdict on you. They are reasons to judge your progress against your own trend, with your physician, rather than against a stranger’s photos.
Weight loss medicine works while you take it. An extension of STEP 1 followed a group of participants for a year after treatment ended. People who stopped semaglutide and the trial’s lifestyle program regained about two-thirds of the weight they had lost. So the plan for month 17 and beyond matters as much as the plan for month 1. Read what happens when you stop semaglutide before you make that call.
At MeliOra Elite Wellness, Dr. Melanie Espinet, a board-certified family physician, prescribes and manages every GLP-1 plan herself. She prescribes semaglutide or tirzepatide and explains your medication at your visit, sets your starting dose, decides each increase based on how you respond and how you feel, and tracks your progress at regular check-ins. Semaglutide starts at $150/month and tirzepatide at $230/month. The monthly price includes physician visits, lab work, the medication and supplies, dose adjustments and check-ins, with no consultation fee.
Visits happen at your home or office anywhere in our Tampa Bay service area with no travel fee, at the Lutz office for select appointments, or by telehealth anywhere in Florida. MeliOra doesn’t promise a number of pounds or a finish date. What you get is a physician who watches your own timeline and adjusts the plan with you. When you’re ready, book a GLP-1 consultation.
Weight loss usually starts in the first month. In the STEP 1 trial, average weight was already lower at the first check at week 4, and it kept falling for more than a year. Everyone responds differently, so your physician judges progress over months, not days.
Expect a steady start, with most of the loss still ahead. In the STEP 1 trial, the weight curve shows steady loss in the first 3 months while the dose was still being raised, but most of the trial’s total loss came after month 3. The trial reported its exact average at week 68, not at 3 months, and results vary widely from person to person.
In the STEP 1 trial, adults on semaglutide 2.4 mg lost an average of 14.9 percent of their body weight by week 68, compared with 2.4 percent on placebo. About half lost 15 percent or more, and about 1 in 7 lost less than 5 percent.
In the SURMOUNT-1 trial, adults on weekly tirzepatide lost an average of 15.0 percent of their body weight on 5 mg, 19.5 percent on 10 mg, and 20.9 percent on 15 mg after 72 weeks, compared with 3.1 percent on placebo. Results varied widely from person to person.
It slows gradually after the first several months and levels off later. In STEP 1, average weight reached its lowest point around week 60. A slowdown is expected, not a sign the medicine stopped working.
An average sits in the middle of a wide range, so many people lose less than it and many lose more. Dose, type 2 diabetes, age, sex, starting weight, side effects that delay dose increases, and daily habits all shape your pace. Your physician can review your own trend and adjust the plan.
No. Weight loss levels off for most people. In STEP 1, the average leveled off around week 60, and in an analysis of SURMOUNT-1, nearly 9 in 10 people who responded to tirzepatide had reached a plateau by week 72.
Usually, yes. In the STEP 1 trial, average weight fell steadily through the first 16 weeks, while the dose was still being raised, so loss was well under way before anyone reached the full 2.4 mg dose. The pace then slowed gradually on the full dose.
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