Tirzepatide15 min readUpdated 2026-04-03

    Tirzepatide 1-Year Results: Long-Term Data

    Review 1-year tirzepatide results from SURMOUNT clinical trials including weight loss outcomes, metabolic improvements, side effect profiles, and what happens after year one.

    Medical Disclaimer

    This article summarizes clinical trial data for educational purposes. Individual results vary. Clinical trial participants are monitored under controlled conditions that may differ from real-world use. Consult your healthcare provider for personalized expectations.

    SURMOUNT Trial Results at 72 Weeks

    The SURMOUNT-1 trial enrolled 2,539 adults with obesity (BMI 30+) or overweight (BMI 27+) with at least one weight-related comorbidity. Participants were randomized to tirzepatide 5mg, 10mg, 15mg, or placebo, with all groups receiving lifestyle counseling.

    Tirzepatide 5mg

    Average weight loss: 15.0% of body weight (34 lbs from 231-lb baseline). 85% of participants achieved at least 5% weight loss. 69% achieved at least 10%. 34% achieved at least 20%.

    Tirzepatide 10mg

    Average weight loss: 19.5% of body weight (45 lbs from 231-lb baseline). 89% achieved at least 5%. 78% achieved at least 10%. 50% achieved at least 20%.

    Tirzepatide 15mg

    Average weight loss: 22.5% of body weight (52 lbs from 231-lb baseline). 91% achieved at least 5%. 84% achieved at least 10%. 57% achieved at least 20%. 36% achieved at least 25%.

    Placebo

    Average weight loss: 3.1% of body weight with lifestyle counseling alone.

    Health Improvements Beyond Weight

    Cardiovascular Markers

    Systolic blood pressure decreased 6-9 mmHg. Triglycerides reduced 25-30%. LDL cholesterol decreased 5-10%. HDL cholesterol increased 5-8%. These improvements significantly reduce estimated 10-year cardiovascular risk.

    Metabolic Health

    Fasting glucose decreased 15-25 mg/dL. Fasting insulin decreased 40-60%. HbA1c decreased 0.5-0.7% in non-diabetic participants. In diabetic participants (SURPASS trials), HbA1c reductions of 2.1-2.6% were observed.

    Inflammatory Markers

    CRP (C-reactive protein) decreased by 35-50%, indicating significant reduction in systemic inflammation. This reduction is associated with lower risk of cardiovascular events, cancer, and other inflammation-driven diseases.

    Quality of Life

    IWQOL-Lite scores improved significantly across all domains: physical function, self-esteem, sexual life, public distress, and work. Physical function improvements were particularly dramatic, with many patients reporting activities they had been unable to do for years.

    What Happens After Year One

    The SURMOUNT-4 trial addressed the critical question of what happens when tirzepatide is discontinued. Participants who achieved at least 5% weight loss on tirzepatide were randomized to continue treatment or switch to placebo. The continuation group maintained their weight loss and continued to lose modestly, while the placebo group regained approximately two-thirds of lost weight over 52 weeks.

    This data reinforces that tirzepatide addresses the biology of obesity (hormonal imbalances, metabolic adaptation) but does not cure the underlying condition. Continued treatment is typically necessary for sustained results, similar to how blood pressure or cholesterol medications require ongoing use. Compounded tirzepatide through Trimi at $125/month makes long-term treatment more accessible.

    Frequently Asked Questions

    How much weight do people lose after 1 year on tirzepatide?

    In the SURMOUNT-1 trial (72 weeks), average weight loss was 15% at 5mg, 19.5% at 10mg, and 22.5% at 15mg. For a 230-pound participant, this translates to roughly 34-52 pounds. Approximately 36% of patients on 15mg lost 25% or more of body weight, and some patients achieved weight loss exceeding 30%.

    Do tirzepatide results plateau after 1 year?

    Weight loss does slow significantly by month 12-15 as the body reaches a new equilibrium. However, the weight lost is maintained as long as the medication continues. The SURMOUNT-3 and -4 trials showed that discontinuing tirzepatide after reaching target weight resulted in significant weight regain, reinforcing the importance of continued treatment for maintenance.

    What health improvements occur after 1 year on tirzepatide?

    Beyond weight loss, 1-year data shows: HbA1c reduction of 2.1-2.6% in diabetic patients, systolic blood pressure reduction of 6-9 mmHg, triglyceride reduction of 25-30%, improvements in sleep apnea severity, reduced liver fat, and improved quality of life scores across all domains.

    Is tirzepatide safe for long-term use?

    Current data extending up to 2 years shows a stable safety profile. Side effects decrease over time as the body adjusts. The most common GI side effects (nausea, diarrhea, constipation) are primarily an issue during dose escalation. Long-term monitoring studies are ongoing to evaluate safety beyond 2 years.

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    Sources & References

    1. Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. NEJM 2021;384:989-1002.
    2. Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. NEJM 2022;387:205-216.
    3. Lincoff AM et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. NEJM 2023;389:2221-2232.
    4. FDA Prescribing Information for Wegovy (semaglutide) and Zepbound (tirzepatide).

    What does 1-year tirzepatide data show?

    SURMOUNT-1 trial 1-year data shows tirzepatide 15 mg produces approximately 21% body-weight reduction at 52 weeks, extending to ~22.5% at 72 weeks (the trial's primary endpoint). Beyond weight loss, 1-year data shows: LDL cholesterol -7%, systolic blood pressure -6 mmHg, HbA1c -0.5 percentage points in non-diabetic patients, and improved waist circumference, sleep quality, and physical functioning scores. Adherence at 1 year: approximately 85% trial retention with ~10-15% discontinuation due to side effects (mostly GI). Body-composition note: ~25-30% of total weight loss is lean mass per Lancet meta-analysis of GLP-1 trials; resistance training plus protein 0.7-1.0 g per pound body weight preserves muscle and metabolic rate. SURMOUNT-4 maintenance trial showed that continuing tirzepatide preserves weight loss at 88 weeks; switching to placebo regains approximately 14% of body weight in 1 year (similar to STEP 4 trial findings with semaglutide). Long-term medication continuation is the standard recommendation. For accessibility, FDA-approved Zepbound or compounded tirzepatide via Trimi Health $125/mo annual.

    ~21% loss at 52 weeks; ~22.5% at 72 weeks.
    LDL -7%, BP -6 mmHg, HbA1c -0.5pp.
    Stopping = ~14% regain in 1 year (SURMOUNT-4).

    Key Takeaways

    • SURMOUNT-1 trial 1-year data: tirzepatide 15 mg produced ~21% body-weight reduction at 52 weeks (extending to ~22.5% at 72 weeks).
    • Cardiovascular risk markers improved: LDL cholesterol -7%, blood pressure -6 mmHg systolic, HbA1c -0.5 percentage points in non-diabetic patients.
    • Adherence at 1 year: ~85% trial retention; ~10-15% discontinuation due to side effects.
    • Body composition: ~25-30% of total weight loss is lean mass per Lancet meta-analysis; resistance training + protein 0.7-1.0 g/lb body weight preserves muscle.
    • SURMOUNT-4 maintenance trial: continuing tirzepatide preserves weight loss at 88 weeks; switching to placebo regains ~14% of body weight in 1 year (similar to STEP 4 with semaglutide).

    Medically Reviewed

    DMR

    Dr. Michael Rodriguez

    MD, FACP, Board Certified in Internal Medicine

    Internal Medicine & Weight Management

    Last reviewed: October 27, 2025

    TCCT

    Written by Trimi Clinical Content Team

    Medical Writers & Healthcare Professionals

    Our clinical content team includes registered nurses, pharmacists, and medical writers who specialize in translating complex medical information into clear, actionable guidance for patients.

    Medically reviewed by Dr. Michael Rodriguez, MD, FACP, Board Certified in Internal Medicine

    What real Trimi patients say

    Verbatim quotes from Trimi's Facebook and Reddit community reviews. First name and last initial preserved per editorial policy.

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    Scientific References

    1. Jastreboff AM, et al. (2022). Tirzepatide Once Weekly for the Treatment of Obesity. The New England Journal of Medicine.Read StudyDOI: 10.1056/NEJMoa2206038
    2. Aronne LJ, et al. (2024). Continued Treatment with Tirzepatide for Maintenance of Weight Reduction in Adults with Obesity (SURMOUNT-4). JAMA.Read StudyDOI: 10.1001/jama.2023.24945
    3. Eli Lilly and Company (2025). Zepbound (tirzepatide) prescribing information. U.S. Food and Drug Administration.Read Study

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