How to Calculate Weight Regain Risk

What is Weight Regain Risk?

The Weight Regain Risk After GLP-1 Discontinuation calculator estimates the probability and magnitude of weight regain after stopping semaglutide or tirzepatide. Based on the STEP 1 extension trial and other withdrawal studies, it models the expected weight trajectory after medication cessation.

Formula

Expected Regain = Weight Lost on GLP-1 × Regain Fraction (typically 0.67 within 1 year of stopping)

WL: Total Weight Lost (lbs) — Total weight lost during GLP-1 treatment
RF: Regain Fraction (0-1) — Proportion of lost weight expected to be regained (typically 0.67 at 1 year)
T: Months Off Medication (months) — Duration since discontinuing GLP-1 therapy
LA: Lifestyle Adherence (low/moderate/high) — Degree of continued diet and exercise compliance after stopping

Step-by-Step Guide

1Enter the total weight lost during GLP-1 therapy and duration of treatment
2Indicate whether you plan to continue lifestyle modifications after stopping
3Select your reason for discontinuation (cost, side effects, goal met, etc.)
4View projected weight at 6, 12, and 24 months after discontinuation

Worked Examples

Input

Lost 40 lbs on Wegovy over 68 weeks, stopping due to cost, moderate lifestyle adherence

Result

Expected regain at 1 year: 40 × 0.67 = 26.8 lbs. Projected weight: starting weight minus 13.2 lbs net loss maintained. With strong lifestyle adherence, regain may be reduced to 50% (20 lbs).

Input

Lost 25 lbs on Mounjaro over 48 weeks, switching to lower-cost maintenance

Result

If switching to lower dose or compounded version: regain risk significantly reduced vs. full discontinuation. Estimated maintenance of 70-85% of weight loss.

Common Mistakes to Avoid

✕Assuming weight loss will be maintained indefinitely after stopping — research consistently shows two-thirds regain within a year
✕Stopping the medication abruptly without a weight maintenance plan including diet, exercise, and behavioral strategies
✕Not recognizing that obesity is a chronic disease requiring ongoing treatment, similar to hypertension or diabetes medications

Frequently Asked Questions

Will I gain all the weight back if I stop Ozempic?

Research from the STEP 1 extension trial shows patients regain approximately two-thirds of lost weight within one year of stopping semaglutide. However, those who maintain healthy eating and regular exercise retain more weight loss. Complete regain to starting weight is not universal but is common without ongoing intervention.

Is it safe to stop GLP-1 medication suddenly?

GLP-1 medications do not cause physical withdrawal symptoms, so abrupt discontinuation is medically safe. However, appetite and food cravings return rapidly, leading to caloric intake rebound. A gradual dose reduction or transition to a maintenance strategy (lower dose, behavioral support, or alternative medication) may help mitigate rapid regain.

Should I stay on GLP-1 medication forever?

Current medical consensus treats obesity as a chronic disease, suggesting long-term or indefinite medication use, similar to blood pressure or cholesterol medications. However, the decision depends on individual factors including cost, side effects, and weight maintenance goals. Discuss a personalized long-term plan with your provider.

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