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What New Weight Loss Drugs Are Coming? Retatrutide Leads at 22.1%

Across 58 trials and 24,214 adults, retatrutide took off 22.10% of body weight and tirzepatide 19.28%. Only one drug on that podium can actually be bought.

Ruth Alvarez10 min read
Weight loss vs placebo, 58 trialsretatrutidenot on saletirzepatideon saleCagriSemanot on saleTwo of the top three are investigational, and intervals overlap besides

Four with published results, and only one of them is buyable. A network meta-analysis of 58 randomized trials covering 24,214 adults put retatrutide at the top, at 22.10% of body weight against placebo (95% CI −25.60 to −18.60) [1]. Tirzepatide came second at 19.28% and CagriSema third at 17.32%, and behind them sit VK2735, UBT251 and ecnoglutide. VK2735 took off 14.7% in 13 weeks [2], UBT251 up to 13.48 kg in 12 [3], and ecnoglutide reached 13.2% at week 40 in a trial run entirely in China [4]. Of all of those, tirzepatide is the only one anyone can obtain, which makes the podium a description of the field rather than a set of choices.

This is the most complete ranking of these drugs published so far, and reading it as a shopping list produces a strange result: most of the podium is unavailable. It is a map of a menu that is still being written, and the drugs on it arrive years apart.

What was pooled

Fifty-eight randomized trials covering 24,214 adults, searched across three databases from 2000 to March 2026, all in people with overweight or obesity and without diabetes. Trials enrolling people with diabetes, or where diabetes status was unclear, were excluded, which makes the comparison cleanly about weight and means none of it describes a diabetes population [1].

Against placebo, retatrutide produced the largest reduction at 22.10%, 95% CI −25.60 to −18.60. Tirzepatide came next at 19.28%, 95% CI −20.39 to −18.16, and CagriSema, a combination of cagrilintide and semaglutide, at 17.32%, 95% CI −19.32 to −15.32. The conventional GLP-1 receptor agonists were more modest, and waist circumference and lipid outcomes followed similar patterns.

The trade at the top

Retatrutide produced the most weight loss and, on low-certainty evidence, also had higher rates of stopping treatment; danuglipron showed the same pattern, while mazdutide was better tolerated.

That is worth registering before anybody concludes the next generation is simply better. A drug that takes off more weight and that more people stop taking has not obviously beaten a gentler one, and the tolerability evidence here is explicitly graded low.

The drugs behind the podium, and how long each was tested

VK2735 pairs GLP-1 with GIP, the same combination as tirzepatide, which makes it a competitor rather than a new mechanism. In a 13-week phase 2 dose-ranging trial, weight fell 14.6 kg (14.7%) at 15 mg against 1.8 kg (1.7%) on placebo, and 130 of 140 treated participants lost at least 5% against 4 of 34 on placebo [2]. Thirteen weeks is a quarter of the 68 weeks behind every approved-drug figure on this site, and the full caution is in the VENTURE result.

UBT251 activates three receptors at once, adding glucagon to GLP-1 and GIP, which is a real mechanistic step rather than another pairing of the same two. Its first-in-human study gave weekly doses for twelve weeks and reported mean losses of 8.96 to 13.48 kg, against a 1.57 kg gain on placebo [3]. Safety was the primary endpoint and weight a secondary readout, and the abstract does not say how many people were in each dose arm, all of which is set out in the first-in-human study.

Ecnoglutide is engineered to favor one downstream signaling pathway, with the intention of separating the metabolic effects from the gastrointestinal ones. Across 664 adults at 36 Chinese centers, week-40 weight loss reached 13.2% against 0.1% on placebo [4]. Adverse events occurred in 93% of each treated group against 84% on placebo, which is broadly the profile of the existing drugs rather than an escape from it. Why its percentages are not comparable to the ones you know is in the ecnoglutide trial.

What the authors say about their own ranking

That confidence intervals overlapped for several comparisons, that head-to-head evidence is limited, and that residual uncertainty should be considered when interpreting comparative effects. Their framing is a probabilistic hierarchy rather than an order of merit.

The intervals are worth reading. Tirzepatide runs from −20.39 to −18.16, which is tight, while retatrutide runs from −25.60 to −18.60, wide enough to reach down into tirzepatide’s range. The difference between first and second place is less settled than the order suggests, which is the standing problem with any pooled ordering.

What a reader can use today

Two things, and the first is that tirzepatide’s position is solid — second place with the narrowest interval on the board, from the largest body of trials, and it is buyable. That is a stronger practical statement than retatrutide’s first place.

The modest tier is where most purchasing actually happens, because semaglutide and the older agonists are what this market sells, and their own evidence is the relevant evidence for almost everybody reading. What is available in which molecule and format is a separate question with a concrete answer.

Frequently asked

What new weight loss drugs are coming?
Retatrutide and CagriSema lead the published rankings, with VK2735, UBT251 and ecnoglutide behind them. Retatrutide produced 22.10% weight loss against placebo across the pooled trials.
Can I buy any of them?
Only tirzepatide, which came second at 19.28%. Retatrutide, CagriSema, VK2735 and UBT251 are investigational, and ecnoglutide is not approved or available outside China.
Is retatrutide better than tirzepatide?
Its point estimate is higher and its interval is wider, reaching down into tirzepatide's range. It also had higher rates of stopping treatment, on evidence the authors grade as low certainty.
Why are the early-phase numbers not comparable?
VK2735 ran 13 weeks and UBT251 ran 12. The weight curve for this class is steepest at the start, and the 68-week trials behind the approved figures include the flat part where agents separate.
What should someone buying today use?
The evidence for semaglutide and the older agonists, because that is what this market sells. A pipeline ranking describes where the field is going, not what is on a shelf.

Sources

  1. [1] Chen D, et al. (2026). Comparative efficacy and safety of glucagon-like peptide 1 based drugs for weight loss in adults with overweight or obesity without diabetes: network meta-analysis of randomised controlled trials BMJ Medicine. PMID 42688617
  2. [2] Bays HE, Toth P, Alkhouri N, Pullman J, Freilich B, Neutel J (2026). Weekly Subcutaneous VK2735, a GIP/GLP-1 Receptor Dual Agonist, for Weight Management: Phase 2, Randomized, 13-Week VENTURE Study Obesity. PMID 41508550
  3. [3] Yang GP, et al. (2026). Safety, Pharmacokinetics and Pharmacodynamics of the GLP-1/GIP/GCG Receptor Agonist UBT251 Injection: A Randomized, Placebo-Controlled Phase 1a/1b Study Diabetes, Obesity and Metabolism. PMID 42712041
  4. [4] Ji L, Gao L, Xue H, Tian J, et al. (2025). Efficacy and safety of a biased GLP-1 receptor agonist ecnoglutide in adults with overweight or obesity: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial The Lancet Diabetes & Endocrinology. PMID 40555243

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