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Study · Non-randomized trial · n = 112 · 2026

11 results

Low-Dose Tirzepatide for Obesity: Comparative Efficacy of 2.5 mg Versus 5 mg in Non-Diabetic Japanese Adults.

Amioka M, Amioka H, Kinoshita H, Sairaku A, Nakano Y

Diabetes, obesity & metabolism28 Jul 2026Cited by 1 (Europe PMC)

PMID42521631 (opens in a new tab)PMCIDPMC13538803 (opens in a new tab)DOI10.1111/dom.71162 (opens in a new tab)PepBankPUB-42521631
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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study11

11 results from studies that gave the peptide. 11 results from people.

  1. 01HumanNon-randomized trialEfficacy outcome

    The proportion reaching the primary outcome did not differ significantly between the tirzepatide 5 mg and 2.5 mg groups.

    In plain wordsIn Japanese adults with obesity, tirzepatide 5 mg and 2.5 mg gave similar chances of reaching the main weight goal.

    Peptide
    Tirzepatide
    Outcome
    No significant changePrimary outcome, 5 mg versus 2.5 mg
    Study

    n = 112

    Comparator
    Tirzepatide 2.5 mg
    Analysis
    Primary
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    Dose not stated · 6 monthsAs given in this study (human).

    Measurements

    HR
    0.93 ratio
    5 mg versus 2.5 mg

    Source sentences

    Summary
    At 6 months, the primary outcome was achieved in 62.1% of the 2.5 mg group and 63.0% of the 5 mg group (HR 0.93, 95% CI 0.58-1.49; p = 0.772).
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  2. 02HumanNon-randomized trialEfficacy outcome

    In non-diabetic Japanese adults with obesity, 62.1% of those on tirzepatide 2.5 mg reached the primary outcome at 6 months.

    In plain wordsIn Japanese adults with obesity, more than half of people on a low tirzepatide dose reached the main weight goal at 6 months.

    Peptide
    Tirzepatide
    Outcome
    DecreasePrimary outcome (BMI below 25 or weight loss above 15%) at 6 months, 2.5 mg
    Study

    n = 58

    Comparator
    Single arm
    Analysis
    Primary
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    2.5 mg weekly · 6 monthsAs given in this study (human).

    Measurements

    Proportion achieving primary outcome
    62.1%
    2.5 mg

    Source sentences

    Summary
    At 6 months, the primary outcome was achieved in 62.1% of the 2.5 mg group and 63.0% of the 5 mg group (HR 0.93, 95% CI 0.58-1.49; p = 0.772).
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  3. 03HumanNon-randomized trialEfficacy outcome

    In non-diabetic Japanese adults with obesity, 63.0% of those on tirzepatide 5 mg reached the primary outcome at 6 months.

    In plain wordsIn Japanese adults with obesity, more than half of people on tirzepatide 5 mg reached the main weight goal at 6 months.

    Peptide
    Tirzepatide
    Outcome
    DecreasePrimary outcome (BMI below 25 or weight loss above 15%) at 6 months, 5 mg
    Study

    n = 54

    Comparator
    Single arm
    Analysis
    Primary
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    5 mg weekly · 6 monthsAs given in this study (human).

    Measurements

    Proportion achieving primary outcome
    63%
    5 mg

    Source sentences

    Summary
    At 6 months, the primary outcome was achieved in 62.1% of the 2.5 mg group and 63.0% of the 5 mg group (HR 0.93, 95% CI 0.58-1.49; p = 0.772).
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  4. 04HumanNon-randomized trialEfficacy outcome

    Mean percent weight loss did not differ significantly between the tirzepatide 5 mg and 2.5 mg groups.

    In plain wordsIn Japanese adults with obesity, weight loss was similar on tirzepatide 5 mg and 2.5 mg.

    Peptide
    Tirzepatide
    Outcome
    No significant changePercent weight loss, 5 mg versus 2.5 mg
    Study

    n = 112

    Comparator
    Tirzepatide 2.5 mg
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    Dose not stated · 6 monthsAs given in this study (human).

    Measurements

    p value
    0.563
    5 mg versus 2.5 mg

    Source sentences

    Summary
    Mean percent weight loss was -15.3% and -16.1%, respectively (p = 0.563)
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  5. 05HumanNon-randomized trialEfficacy outcome

    Tirzepatide 2.5 mg and 5 mg gave similar reductions in BMI.

    In plain wordsIn Japanese adults with obesity, BMI fell by a similar amount on both tirzepatide doses.

    Peptide
    Tirzepatide
    Outcome
    No significant changeBMI reduction, 5 mg versus 2.5 mg
    Study

    n = 112

    Comparator
    Tirzepatide 2.5 mg
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    Dose not stated · 6 monthsAs given in this study (human).

    Source sentences

    Summary
    similar reductions in BMI, skeletal muscle mass, and bone mass.
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  6. 06HumanNon-randomized trialEfficacy outcome

    Tirzepatide 2.5 mg and 5 mg gave similar reductions in skeletal muscle mass.

    In plain wordsIn Japanese adults with obesity, muscle mass fell by a similar amount on both tirzepatide doses.

    Peptide
    Tirzepatide
    Outcome
    No significant changeSkeletal muscle mass reduction, 5 mg versus 2.5 mg
    Study

    n = 112

    Comparator
    Tirzepatide 2.5 mg
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    Dose not stated · 6 monthsAs given in this study (human).

    Source sentences

    Summary
    similar reductions in BMI, skeletal muscle mass, and bone mass.
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  7. 07HumanNon-randomized trialEfficacy outcome

    Tirzepatide 2.5 mg and 5 mg gave similar reductions in bone mass.

    In plain wordsIn Japanese adults with obesity, bone mass fell by a similar amount on both tirzepatide doses.

    Peptide
    Tirzepatide
    Outcome
    No significant changeBone mass reduction, 5 mg versus 2.5 mg
    Study

    n = 112

    Comparator
    Tirzepatide 2.5 mg
    Outcome group
    Bone and joint · Musculoskeletal
    Studied dose
    Dose not stated · 6 monthsAs given in this study (human).

    Source sentences

    Summary
    similar reductions in BMI, skeletal muscle mass, and bone mass.
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  8. 08HumanNon-randomized trialSafety outcome

    Adverse events were more frequent with tirzepatide 5 mg than with 2.5 mg.

    In plain wordsIn Japanese adults with obesity, side effects were more common on tirzepatide 5 mg than on 2.5 mg.

    Peptide
    Tirzepatide
    Outcome
    IncreaseAdverse events, 5 mg versus 2.5 mg
    Study

    n = 112

    Comparator
    Tirzepatide 2.5 mg
    Outcome group
    Adverse events · Metabolic and weight
    Studied dose
    Dose not stated · 6 monthsAs given in this study (human).

    Measurements

    Adverse event frequency
    50%
    5 mg
    Adverse event frequency
    35%
    2.5 mg

    Source sentences

    Summary
    Adverse events were more frequent with 5 mg (50% vs. 35%), primarily gastrointestinal symptoms.
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  9. 09HumanNon-randomized trialEfficacy outcome

    In non-diabetic Japanese adults with obesity, mean percent weight loss on tirzepatide 2.5 mg was 15.3% at 6 months.

    In plain wordsIn Japanese adults with obesity, people on a low tirzepatide dose lost about 15% of their weight in 6 months.

    Peptide
    Tirzepatide
    Outcome
    DecreasePercent weight loss at 6 months, 2.5 mg
    Study

    n = 58

    Comparator
    Single arm
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    2.5 mg weekly · 6 monthsAs given in this study (human).

    Measurements

    Mean percent weight loss
    −15.3%
    2.5 mg

    Source sentences

    Summary
    Mean percent weight loss was -15.3% and -16.1%, respectively (p = 0.563)
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  10. 10HumanNon-randomized trialEfficacy outcome

    In non-diabetic Japanese adults with obesity, mean percent weight loss on tirzepatide 5 mg was 16.1% at 6 months.

    In plain wordsIn Japanese adults with obesity, people on tirzepatide 5 mg lost 16.1% of their weight in 6 months.

    Peptide
    Tirzepatide
    Outcome
    DecreasePercent weight loss at 6 months, 5 mg
    Study

    n = 54

    Comparator
    Single arm
    Outcome group
    Body weight · Metabolic and weight
    Studied dose
    5 mg weekly · 6 monthsAs given in this study (human).

    Measurements

    Mean percent weight loss
    −16.1%
    5 mg

    Source sentences

    Summary
    Mean percent weight loss was -15.3% and -16.1%, respectively (p = 0.563)
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).
  11. 11HumanNon-randomized trialSafety outcome

    The adverse events in the tirzepatide groups were primarily gastrointestinal symptoms.

    In plain wordsIn Japanese adults with obesity on tirzepatide, most side effects were stomach and gut symptoms.

    Peptide
    Tirzepatide
    Outcome
    Not applicableGastrointestinal symptoms among adverse events
    Study

    n: not reported in source

    Outcome group
    Gastrointestinal adverse events · Gastrointestinal
    Studied dose
    Dose not stated · 6 monthsAs given in this study (human).

    Source sentences

    Summary
    Adverse events were more frequent with 5 mg (50% vs. 35%), primarily gastrointestinal symptoms.
    2 context sentences
    Summary · context
    This multicentre, prospective, non-randomised cohort study enrolled non-diabetic Japanese adults (18-65 years) with BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with comorbidities.
    Summary · context
    Of 112 participants analysed (58 on 2.5 mg, 54 on 5 mg), baseline characteristics were well balanced (mean BMI 30.8 kg/m2).

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    12 Oct 2026, 12:10 UTC

    Study results updated

  2. Version 1

    9 Oct 2026, 03:07 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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