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Weight Loss on GLP-1s

Maintenance planner

See what the randomised withdrawal trials measured when people continued or stopped semaglutide or tirzepatide, applied as arithmetic to your own weight, then build a list of questions for your prescriber from what is driving your decision. No dosing advice and no recommendation to continue or stop.

By FormBlends editorial teamAssumptions checked September 4, 2026Runs in your browser; nothing is sent to a server

Your situation

Selects which randomised withdrawal trial to show. Both trials used the brand product at label doses.

lb
lb

Tick any that apply. Each adds questions to the list.

What STEP 4 measured

803 adults who had lost a mean 10.6 percent over 20 weeks on semaglutide were randomised to continue or to switch to placebo for 48 more weeks. Continue: -7.9 percent more. Switch: +6.9 percent. Difference -14.8 points (95% CI -16 to -13.5). PubMed 33755728.

Share of the lead-in loss the placebo arm regained

58%

Derived: baseline 100, after lead-in 89.4, after switch 95.6.

Net from baseline at trial end

-17.7 vs -4.4%

Continued vs switched to placebo, derived from the two published percentages.

Those averages applied to your weight

Enter your current weight. Enter your starting weight too to see what you have lost so far and, for semaglutide, the one-year off-treatment follow-up applied to it.

Questions for your prescriber

  1. What did STEP 4 and SURMOUNT-4 show about weight after stopping, and how does that apply to someone with my history?
  2. If I stop, how will we monitor weight, blood pressure, glucose and lipids, and at what point would you want to see me again?
  3. Is there a maintenance approach you use after stopping, and what evidence is it based on?
  4. If I continue, what does the plan look like for the next year: visits, labs, and what would make you change it?
  5. What are the options if I want to continue but the current arrangement is not working (schedule, product, supply)?
Paste into your notes or patient portal message.
Formulashown in full, nothing hidden
weight if continue arm matched = weight now x (1 + continue % / 100)
weight if placebo arm matched  = weight now x (1 + switch % / 100)
share of loss regained         = ((1 + lead-in %) x (1 + switch %) - (1 + lead-in %)) / (1 - (1 + lead-in %))   [all as fractions]
net from baseline at trial end = ((1 + lead-in %) x (1 + arm %) - 1) x 100
STEP 1 extension share         = 11.6 / 17.3 = 0.67 of the loss regained in the year after week 68
1 lb = 0.45359237 kg

STEP 4 (PubMed 33755728): 20-week run-in on semaglutide 2.4 mg, mean -10.6 percent; then 48 weeks randomised, continue -7.9 percent vs placebo +6.9 percent, difference -14.8 points (95% CI -16.0 to -13.5). SURMOUNT-4 (PubMed 38078870): 36-week lead-in on tirzepatide 10 or 15 mg, mean -20.9 percent; then 52 weeks randomised, continue -5.5 percent vs placebo +14.0 percent, difference -19.4 points (95% CI -21.2 to -17.7). STEP 1 extension (PubMed 35441470): 327 participants followed one year off treatment; semaglutide group -17.3 percent at week 68 and -5.6 percent at week 120, regaining 11.6 points, about two-thirds of the loss.

Percentages in the randomised phases are relative to the weight at randomisation, not to baseline, which is why the net-from-baseline row is derived by multiplying the two changes.

Assumptions, checked September 4, 2026

  • The trials used brand products at label doses with diet and activity counselling throughout. Compounded GLP-1 products are not FDA approved and are not interchangeable with brand products; the trial numbers do not describe them.
  • The planner applies published arm means to a weight. It has no information about you beyond two numbers, so it cannot forecast your course. The spread inside each arm was wide.
  • The tirzepatide row uses SURMOUNT-4, whose lead-in was at 10 or 15 mg. No tirzepatide off-treatment follow-up comparable to the STEP 1 extension is included.
  • The question list is generated from your selections. It contains no dosing suggestions and no recommendation to continue or stop. Both are decisions for you and a licensed prescriber.
  • Pregnancy planning wording follows the Wegovy prescribing information, which advises discontinuing at least 2 months before a planned pregnancy. Check the label for your own medication with your prescriber.

This calculator is an arithmetic aid for medication a licensed prescriber has already prescribed. It does not recommend a dose. Confirm any result with your prescriber or pharmacist before use.

Sources

  1. Rubino D et al. Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance (STEP 4). JAMA 2021. PubMed 33755728
  2. Aronne LJ et al. Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity (SURMOUNT-4). JAMA 2024. PubMed 38078870
  3. Wilding JPH et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes Obes Metab 2022. PubMed 35441470
  4. Wegovy (semaglutide) prescribing information, NDA 215256, Drugs@FDA
  5. Zepbound (tirzepatide) prescribing information, NDA 217806, Drugs@FDA

Read before you use it

Guides for this calculator

Maintenance and stopping: what STEP 4, SURMOUNT-4 and the STEP 1 extension measured

The three trials that followed people after semaglutide or tirzepatide was withdrawn, with the numbers, what they do and do not tell you, and how to turn them into a conversation with your prescriber.

Updated September 4, 2026

Educational, not medical advice. Read the medical disclaimer.