Peptide basics

Semaglutide vs tirzepatide: comparing the evidence record, not the effect

Every figure below describes the public research and regulatory record: how many studies were registered, how far they progressed, what has been approved, how many papers were indexed, and how many people read about each compound. None of it describes what either compound does in a body.

What this comparison measures

Everything on this page is a property of the record rather than of the molecule: how many studies were registered under each name, how far those studies progressed, which regulators approved which products, how many papers were indexed, and how many people read about each compound. These are countable, and they are checkable against the sources listed at the foot of the page.¹²³⁴

Registered human trials

In PepRack's evidence snapshot, collected on 1 August 2026, a ClinicalTrials.gov search for semaglutide returned 730 loose matches, of which 589 were confirmed to name semaglutide as an intervention. The same search for tirzepatide returned 270 loose matches, of which 222 were confirmed.¹²

The loose-match figure is worth keeping in view. Registry search is fuzzy, and a raw count includes studies that merely mention a compound. The verified count is the one that answers the question people are actually asking — how many registered studies administered this compound — and it is the smaller of the two in both cases.¹²

• Semaglutide: 589 verified registered studies from 730 raw registry matches.
• Tirzepatide: 222 verified registered studies from 270 raw registry matches.
• Both counts are of study registrations, not of completed studies, and not of published results.¹²

Furthest phase reached

Both compounds have registered phase-4 studies, which are conducted after a product has been approved. In the snapshot, semaglutide's phase distribution includes 155 phase-3 and 93 phase-4 registrations; tirzepatide's includes 47 phase-3 and 38 phase-4 registrations.¹²

This is the strongest form of parity available in this dataset. On the great majority of compounds tracked on this site, the furthest phase reached is phase 2, or there is no registered phase at all. Two compounds both carrying phase-4 records are unusual, and it is the single most important thing this comparison establishes.¹²

Regulatory status

Semaglutide is the active ingredient in three approved US brands recorded in Drugs@FDA: WEGOVY under NDA 215256, OZEMPIC under NDA 209637, and RYBELSUS under NDA 213182. Tirzepatide is the active ingredient in two: ZEPBOUND under NDA 217806 and MOUNJARO under NDA 215866.¹²¹³

The approved labelling for each product states the conditions it was approved to treat and the evidence submitted in support. What a label does not do is compare one product against the other, because approval is a decision about a single application rather than a ranking exercise.⁵⁶⁷⁸

PepRack's snapshot records semaglutide's primary FDA entry as WEGOVY and tirzepatide's as ZEPBOUND. The collector ranks currently-marketed products first, so the primary entry is whichever presentation is on the market rather than the best-known brand; the full application lists are in the linked openFDA queries.¹²¹³

Publication trend, 2017 to 2026

A title-and-abstract search of PubMed across 2017 to 2026 returns 5,153 records for semaglutide and 2,314 for tirzepatide. The 2026 figures in both series are partial, because the year was incomplete when the data was collected.³⁴

The shape of the two series differs more than the totals do. Semaglutide is indexed continuously from 2017 onward, rising from 76 records that year to 1,677 in 2025. Tirzepatide records begin in 2020 with 10, reaching 905 in 2025. Roughly speaking, tirzepatide's literature is three years younger and is growing at a similar rate.³⁴

The one direct head-to-head

SURPASS-2 randomly assigned adults with type 2 diabetes to tirzepatide or to semaglutide, making it the rare published trial in which both compounds were administered inside the same protocol with the same measurements.¹¹

Its existence matters for a specific reason. Comparisons assembled by placing STEP 1 next to SURMOUNT-1 are comparisons across trials with different populations, different durations and different endpoints, and differences between such trials cannot be attributed to the compounds. A single randomised comparison is a different class of evidence from two separate trials read side by side.⁹¹⁰¹¹

Semaglutide holds the largest registered-trial record of any compound tracked on this site, and the deepest phase-4 record among the metabolic compounds.

Tirzepatide's registered-trial record is smaller in absolute terms and younger by roughly three years, and it also reaches phase 4.

Attention against evidence

The English Wikipedia article on semaglutide averaged 54,466 views a month between February and June 2026, peaking at 65,268. Tirzepatide averaged 38,322, peaking at 46,922. Both are among the most-read compounds on this site.¹²¹⁴

For this pair, attention and evidence point the same way — the more-read compound is also the more-studied one. That alignment is not the usual case. Several compounds tracked here are read by tens of thousands of people a month and have no registered trial at all, and readership is reported precisely so that the mismatch is visible where it exists.¹²

What the numbers cannot settle

Trial counts are counts of registrations. A registration says a study was planned and recorded; it does not say the study finished, that its results were published, or what those results were. Two compounds with identical counts can have entirely different published records.¹²

Common questions