Petrelintide vs Eloralintide

Forty-two weeks of treatment, a nine-week safety follow-up, and a primary endpoint at week 28. Escalation ran every fourth week, and the company reported that 88 to 98 percent of participants reached their targeted maintenance dose. How many escalation steps each arm went through has not been published, so how long any arm actually spent sitting at its maintenance dose is not public information.

Forty-eight weeks of treatment with the primary endpoint at week 48. Two of the seven arms escalated rather than holding one level throughout: one stepped up once after twenty weeks, the other twice inside the first eight weeks and then held for the remaining forty. The registry publishes the schedule for every arm, so time at maintenance dose is knowable arm by arm. Six weeks of extra treatment is a real difference, and on its own it does not explain the gap in the headline percentages.

The baseline set presented at the American Diabetes Association 2026 Scientific Sessions covered 485 participants: 53 percent female, mean age 47, mean body mass index 36.7, mean body weight 107.1 kg. Entry required a body mass index of 30 or above, or 27 or above with hypertension or dyslipidemia. Type 1 and type 2 diabetes were both exclusions, and screening carried a glycated haemoglobin ceiling.

263 participants: 78 percent female, mean age 49.0, mean body mass index 39.1, mean body weight 109.1 kg. Entry required a body mass index of 30 or above, or 27 or above with at least one weight-related comorbidity, and diabetes was an exclusion. The 25 percentage-point difference in the female share between the two trials is not cosmetic. A 2026 prospective study of semaglutide with body composition measured by dual-energy X-ray absorptiometry reported greater weight and fat-mass loss in women than in men, which is exactly the kind of imbalance that shifts a mean percentage without anything happening at the receptor.

The company reported the week 42 figure under what it calls the efficacy estimand, and stated that the treatment-regimen estimand results were largely consistent with it. Neither analysis set has appeared in a peer-reviewed table, so a reader has to take that consistency claim on trust.

The Lancet reports the week 48 figures under the efficacy estimand, with the full analysis set and confidence intervals printed. Estimand choice matters more than most readers expect, because it decides whether people who stopped the medicine still count toward the average, and a large trial can move several percentage points between one estimand and another. When a press release and a journal paper disagree about the same trial, this is usually why.

Zealand reported no unexpected safety signal for alopecia, fatigue or neuropsychiatric events, and described local reactions as very low and consistent with placebo. Overall withdrawal from the trial for any reason ran at 8.4 percent across petrelintide treatment arms against 13.6 percent for placebo, while discontinuation for adverse events was reported as 4.8 percent for the maximally effective petrelintide arm against 4.9 percent for placebo. Those two figures do not share a denominator: the first is pooled across arms, the second is a single arm. No per-arm fatigue table has been published.

The Lancet prints fatigue arm by arm as well: 0 percent, 13 percent, 29 percent, 43 percent, 46 percent and 21 percent across the six eloralintide arms, against 12 percent for placebo. Fatigue tracking dose that closely is the kind of finding that survives peer review and does not survive a topline summary. It does not show that petrelintide is gentler on fatigue, only that one dataset reports fatigue arm by arm and the other does not.

Tolerability. Zealand and Roche have framed petrelintide from the outset as a compound meant to change how weight management feels, and the ZUPREME-1 material leads on the absence of vomiting in the best-performing arm and on a discontinuation rate that matched placebo almost exactly. A programme aiming at a gentler profile and a programme aiming at the largest achievable number will not produce comparable headline percentages, and neither result tells you which molecule does more at matched exposure.

Depth of effect across a wide range. The eloralintide phase 2 ran six arms including two escalation schemes and pushed to a level where roughly two thirds of participants in one arm reported nausea. That design answers a different question, which is how far this pathway goes when you push it and what the cost is at each step. Both designs are legitimate. They answer different questions, so their outputs are not interchangeable.

Petrelintide is not approved by the FDA for any use, and it is not approved anywhere else. It is not sold as a medicine and not sold as a supplement. The only people with legitimate access to it are participants in the trials described above.

Eloralintide is not approved by the FDA for any use, and it is not approved anywhere else. It exists inside Eli Lilly's trial programme. Material advertised online under either name sits outside both supply chains, and no published analysis tells you what is in it. Neither compound is something a reader can obtain lawfully outside a trial, which makes this comparison a research question rather than a shopping decision.