Is tirzepatide approved for children?

No. It is not authorised for paediatric obesity. Both studies described are registered clinical trials.

Why are there separate trials for different ages?

Puberty falls between the two age bands and changes body composition, growth velocity and hormonal context substantially.

Is the Phase 1 study an efficacy trial?

No. Its primary outcome is treatment-emergent and serious adverse events — it is a safety and tolerability study in 28 children.

GLP-1 & Incretin Science

What Is Actually Registered, and at What Phase

JMWritten & reviewed by Jack Muncaster · Founder, UK PeptidesLast reviewed 2026-08-233 cited sources

Two registered tirzepatide trials cover younger populations. NCT06075667 is a Phase 3 in 160 adolescents aged 12 to 17 with a BMI primary endpoint. NCT05696847 is a completed Phase 1 in 28 children aged 6 to 11 whose primary outcome is adverse events.

Key facts

NCT06075667: Phase 3, n=160, ages 12–17
Its status: Active, not recruiting
Its primary outcome: Percent change from baseline in BMI
Primary completion: 2 June 2026
NCT05696847: Phase 1, n=28, ages 6–11
Its status: Completed
Its primary outcome: Treatment-emergent and serious adverse events
Sponsor: Eli Lilly and Company

Why the phase distinction is not pedantry

A Phase 3 in 160 adolescents is designed to establish whether the compound works and is powered for an efficacy endpoint. A Phase 1 in 28 children is designed to characterise safety and tolerability, with adverse events as the primary outcome. Reporting the second as a dedicated paediatric obesity trial with results pending sets an expectation the study was never built to meet.

The age split is deliberate

One trial covers 12 to 17, the other 6 to 11. Those are different populations physiologically, not merely different numbers — puberty falls between them, and it changes body composition, growth velocity and hormonal context substantially. Regulators generally require separate evidence for separate age bands for exactly this reason.

Research material referenced

Retatrutide 10mg — third-party HPLC tested

View — £59.99

What the Phase 3 measures

Percent change from baseline in body mass index, per the registry. Not body weight. That follows directly from the participants still growing, and it means the eventual headline number will not be comparable with adult tirzepatide figures however similarly it is reported.

The naming problem, again

NCT06075667 is referred to in coverage under a programme acronym that the registry does not carry — its acronym field is empty. This is the second time on this site that a trial widely discussed by name has turned out to have no registered acronym, the other being the CagriSema head-to-head. Searching a programme name can return nothing while the trial exists.

Where the timeline actually sits

The registry records primary completion for NCT06075667 as 2 June 2026, with the study active and not recruiting. Primary completion means the last participant has reached the primary endpoint assessment, so data exists; publication follows separately and is not automatic or immediate.

The boundary that applies throughout

Tirzepatide is a licensed medicine for adults and is not authorised for paediatric obesity. These are registered trials under clinical supervision with ethics approval. Nothing supplied on this site is tirzepatide, relates to it, or is appropriate for a child in any circumstance.

Quick reference

	NCT06075667	NCT05696847
Phase	3	1
Enrolment	160	28
Ages	12–17	6–11
Primary outcome	% change in BMI	Adverse events
Status	Active, not recruiting	Completed

Extended research context

The GLP-1 & Incretin Science deep dive

Deep dive: the two routes to a bigger effect

Every compound trying to beat GLP-1 alone has taken one of two routes. The first adds more receptors from the same hormone family — GIP in tirzepatide, GIP and glucagon in retatrutide. The second adds a non-incretin satiety hormone, which in practice means amylin: CagriSema combines cagrilintide with semaglutide, and amycretin engages both receptors from one molecule. Both routes work, because they recruit signalling pathways that do not fully overlap. Neither has escaped the constraint that binds all of them, which is that gastrointestinal tolerability worsens as effect size grows.

Deep dive: why a percentage is not a result

The most-quoted numbers in this field are the least comparable. REDEFINE 1 reported 22.7% and 20.4% for the same compound in the same trial — the first among participants who adhered to treatment, the second across everyone randomised. TRIUMPH-1 reported 28.3% in an uncomplicated obesity population while TRIUMPH-3 reported up to 22.6% in adults with established cardiovascular disease, using the same compound. Before any two figures can be compared they have to match on estimand, population, duration, comparator and whether the number is placebo-adjusted. Most published comparisons match on none of them.

Deep dive: what happens after the trial stops

Every headline figure describes weight while treatment continues. The STEP-1 extension found that a year after semaglutide was stopped, participants had given back roughly two-thirds of what they lost, moving from 17.3% mean reduction to a net 5.6% — though average weight remained below baseline and nearly half stayed at least 5% down. Meta-analysis puts regain at around 0.8 kg per month. This is why maintenance studies such as TRIUMPH-6 matter more to the field's future than another two points of peak reduction.

Research applications

▸Comparing incretin and amylin compounds on a like-for-like basis
▸Interpreting estimands, thresholds and placebo-adjusted figures in trial reports
▸Tracking the obesity pipeline across sponsors and jurisdictions
▸Understanding receptor pharmacology behind GLP-1, GIP, glucagon and amylin
▸Distinguishing licensed medicines from investigational compounds

Handling checklist

✓Identify which estimand a quoted percentage comes from before citing it
✓Check the trial population and baseline BMI against the comparison you are making
✓Confirm the duration and whether the reduction curve had plateaued
✓Read discontinuation rates alongside efficacy figures
✓Verify every NCT identifier against ClinicalTrials.gov rather than secondary reporting

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Comparing headline percentages across different trials

Fix: Population, duration, estimand and comparator all differ; the numbers are not interchangeable.

✗ Quoting the larger of two figures from the same trial

Fix: Name the estimand. Efficacy and treatment-policy answer different questions.

✗ Treating peak reduction as a durable outcome

Fix: Substantial regain follows cessation across the class; peak figures describe a maintained state.

✗ Assuming an oral route means a weaker mechanism

Fix: Route and receptor count are independent. Orforglipron is weaker because it hits one receptor, not because it is a tablet.

✗ Reading investigational compounds as available treatments

Fix: Most of this pipeline holds no authorisation anywhere; mazdutide is approved only in China.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Frequently asked questions

Is tirzepatide approved for children?: No. It is not authorised for paediatric obesity. Both studies described are registered clinical trials.
Why are there separate trials for different ages?: Puberty falls between the two age bands and changes body composition, growth velocity and hormonal context substantially.
Is the Phase 1 study an efficacy trial?: No. Its primary outcome is treatment-emergent and serious adverse events — it is a safety and tolerability study in 28 children.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

Written and reviewed by

Jack Muncaster · Founder, UK Peptides

Jack founded UK Peptides in Manchester after repeatedly receiving research compounds with missing or recycled paperwork. He is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate.

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