Data investigation

The Drugs That Are Not Here Yet

Four investigational molecules have published human results. The most striking figure among them — 8% of body weight in four weeks — comes from the earliest and smallest study of the four.

By Nora Bissett · Pricing Editor
Editorially reviewed & fact-checked against primary sources · How we verify contentLast reviewed
8 min read·4 citations

Four molecules in development have published human results, and the most striking number among them — 8% of body weight in four weeks — comes from the earliest and smallest study of the four.[4] That is not a coincidence. Ranking these drugs by their headline figures ranks them by how short their trials were, and every one of them will reach peptide sellers before it reaches a pharmacy.

What has actually been published

Human weight results for four investigational agents, with the trial stage and length that produced them.
DrugStageWeight changeOver
Aleniglipron (oral)[1]Phase 2b, 230 people−11.3% vs placebo at 120 mg36 weeks
Bofanglutide (biweekly)[2]Phase 2b, 340 people−9.75% to −16.69% vs −1.15% placebo30 weeks
CT-388[4]Phase 1, healthy volunteers−4.7% to −8.0% vs −0.5% placebo4 weeks
LY3537021 (GIP alone)[3]Phase 1, 85 people3.14 kg vs 0.36 kg placebo at 25 mg57 days
Read the last column before the third. Weight loss on these drugs is front-loaded — steepest early, flattening as it goes. A four-week figure is measured entirely on the steep part. Nothing in this table can be projected forward, and comparing across rows compares trial durations as much as molecules.

The finding worth caring about is not a weight number

LY3537021 is the least impressive drug in that table and the most interesting entry in it. It is a GIP receptor agonist on its own — no GLP-1 component — which makes it an experiment on the question the whole field wants answered.

It produced dose-dependent weight loss that persisted 35 days after the last dose. And it did so with no delay in gastric emptying at any dose tested, and infrequent gastrointestinal side effects.

Weight came off without the stomach being slowed down.

That matters because delayed gastric emptying is where the nausea, vomiting and constipation come from, and those are why people stop — roughly one in ten in the trials covered elsewhere on this register. If GIP produces weight loss by a route that does not involve slowing the stomach, then the side effects and the benefit may be separable, which nobody has yet demonstrated in an approved drug.

Two cautions on the same result. The weight effect is modest at these doses — 3.14 kg against 0.36 kg on placebo. And the glucose effect did not hold: reductions in fasting glucose were transient and were no longer significantly different from placebo by day 29. On this evidence GIP alone looks like a weight drug rather than a diabetes drug, which is not what a GIP agonist was expected to be.

The biweekly one

Bofanglutide is designed to be injected once every two weeks, and posted the largest weight reduction in the table — up to 16.69% at 30 weeks against 1.15% on placebo, in 340 Chinese adults.

That is the disciplined version of something people already improvise. Stretching a weekly drug to fortnightly, to make it affordable, rests on a mathematical model and two patients — stretching doses to save money. A molecule engineered for that interval and tested at it is a different proposition entirely.

Its tolerability description and its tolerability numbers do not match. The paper concludes the drug is generally well tolerated. It also reports adverse events in 98.9% of people taking it — 271 of 274 — against 86.4% on placebo, with gastrointestinal events in 83.9% against 33.3%. Most were mild, and nearly everybody had one.

Two further limits on transferring that result. The trial used Chinese BMI thresholds, where overweight begins at 24 and obesity at 28 rather than the 25 and 30 used in the United States, so the population is lighter than a Western trial of the same labels. And the average participant was 33 years old.

What this means for what appears online

Every drug above is unapproved. None has a label, an approved manufacturer, or a legal route to a pharmacy. A published phase 2 result is the strongest free marketing a gray-market seller ever receives, and the pattern is established — we track eleven sellers already offering retatrutide, which is also unapproved everywhere, in retatrutide’s phase 3 and the gray market.

  • Phase 1 means safety and dose-finding, in tens of people, over weeks. It is not evidence a drug works.
  • Phase 2b means a dose has been chosen and an effect estimated in a few hundred people. It is not evidence a drug is safe over years.
  • A short trial flatters every drug in this class. Check the duration before the percentage.
  • Certainty gradings exist. The BMJ synthesis of 262 trials rates the newest agents very low to low certainty — what 262 trials say together.

One housekeeping note: the aleniglipron paper carries a published erratum whose contents we have not read. We mention it because a correction exists, not because we know what it changes.

Frequently Asked Questions

References

  1. 1.Rosenstock J, Lingvay I, Ryan D, et al. Oral small molecule GLP-1 receptor agonist aleniglipron in people with overweight or obesity: a randomized, double-blind, placebo-controlled phase 2b trial Nature Medicine. 2026. PMID: 42249138.
  2. 2.Ji L, Gao L, Tian J, et al. Efficacy and safety of bofanglutide, a GLP-1 receptor agonist, in Chinese adults with overweight or obesity: a randomized, double-blind, placebo-controlled phase 2b trial Signal Transduction and Targeted Therapy. 2026. PMID: 41760612.
  3. 3.Roell W, Alsina-Fernandez J, Qu H, et al. Long-acting GIPR agonist LY3537021 reduces body weight and fasting blood glucose in patients with T2D: Preclinical development and phase 1 randomized ascending dose studies Molecular Metabolism. 2026. PMID: 41391569.
  4. 4.Chakravarthy MV, Rodriguez R, Hergarden A, et al. Effects of CT-388, a once-weekly signaling-biased dual GLP-1/GIP receptor agonist, on weight loss and glycemic control in preclinical models and participants with obesity Molecular Metabolism. 2026. PMID: 41319798.

Where to get GLP-1 online, safely: sellers our editors have checked

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8.3

SnagRx

Semaglutide at $99/month, 48% under the register median

9.3

Embody

Knowing which pharmacy fills the vial — it names RedRock Pharmacy

8.2

YourEra

Semaglutide at $99/month, 63% under the register median