Semaglutide
ApprovedA long-acting GLP-1 receptor agonist approved for type 2 diabetes and for weight management, dosed once weekly.
Weight loss
Category
Weight loss
GLP-1 agonists and the dual and triple agonists that followed them. The best-evidenced group on this site, and the one most often sold as something it is not.
Nearly everything here works on the incretin system. Those are the gut hormones released when you eat, and they do several jobs at once — signal fullness to the brain, slow the rate the stomach empties, sharpen the insulin response to a meal. Natural GLP-1 is broken down within minutes. These drugs are engineered to survive. That is how a once-weekly injection became possible at all.
Two things are true of this category at the same time. The clinical evidence is better than anywhere else on this site: phase 3 programmes, hard endpoints, approved products with names you have heard. And the gap between the licensed medicine and what gets sold online is wider here than in any other category. The second thing follows from the first. Nobody bothers to counterfeit a compound nobody wants.
Tirzepatide
ApprovedA once-weekly dual agonist that activates both the GIP and GLP-1 receptors, approved for type 2 diabetes and for weight management.
Weight loss
Retatrutide
Early human trialsAn investigational once-weekly triple agonist acting on the GLP-1, GIP and glucagon receptors. Not approved anywhere.
Weight loss
Liraglutide
ApprovedThe first GLP-1 analogue approved for weight loss. A daily injection, superseded by weekly semaglutide but still the best-documented compound in the class.
Weight loss
Cagrilintide
Clinical trialsA long-acting amylin analogue in late-stage trials. It works on a different satiety pathway from the GLP-1 drugs. Which is why it is being developed alongside semaglutide rather than against it.
Weight loss
Orforglipron
ApprovedThe first GLP-1 pill that is a true small molecule. Approved in April 2026, and taken any time of day with no food or water restrictions.
Weight loss
Mazdutide
Approved for another indicationA GLP-1 and glucagon dual agonist approved in China in 2026. Not approved in the United States, and the US pathway is undecided.
Weight loss
Survodutide
Clinical trialsA GLP-1 and glucagon dual agonist in phase 3, and one of the more advanced candidates for fatty liver disease rather than weight alone.
Weight loss
Eloralintide
Clinical trialsAn amylin receptor agonist that produced up to 20% weight loss in phase 2, as a single agent. That last part is what makes it notable.
Weight loss
Tesofensine
Early human trialsA triple monoamine reuptake inhibitor, not a peptide and not an incretin. It works on the brain's reward and arousal systems, with the side effects that implies.
Weight loss
5-Amino-1MQ
PreclinicalAn oral NNMT inhibitor with striking results in obese mice and no human data whatsoever. Not a peptide, despite where it is sold.
Weight loss
Adipotide
PreclinicalA peptide designed to kill the blood supply feeding fat tissue. It worked in monkeys, and it damaged their kidneys.
Weight loss
Tesamorelin
Approved for another indicationA GHRH analogue approved by the FDA for reducing excess visceral fat in HIV-associated lipodystrophy. The only compound in this category with completed phase 3 trials.
Muscle & performance · Weight loss · Anti-aging & longevity
Fat Blaster
PreclinicalA marketing name, not a formula. What is in the syringe varies by clinic, and no version of it has been shown to cause weight loss.
Weight loss
Lipo-C
PreclinicalThe same compounded lipotropic injection under a different name, usually with L-carnitine added. The evidence position is identical: none.
Weight loss
L-Carnitine
ApprovedAn essential cofactor for burning fat, and not the step that limits it. Approved for genuine carnitine deficiency; sold by injection for weight loss on weak evidence.
Weight loss · Muscle & performance
SLU-PP-332
PreclinicalA mouse compound that got a press release. It reproduced some effects of endurance training in mice, and no human has ever taken it.
Weight loss · Muscle & performance
AOD-9604
Early human trialsA growth hormone fragment developed as an obesity drug. It completed human trials, and they did not show weight loss beyond placebo.
Weight loss
Count the receptors
The generations sort themselves out once you know what to count. Liraglutide and semaglutide act at one receptor, GLP-1. Tirzepatide adds GIP. Retatrutide adds glucagon on top of both. Survodutide takes GLP-1 and glucagon and leaves GIP out.
More receptors has generally meant more average weight loss in the trials. It has also meant more ways to feel unwell. The pattern holds well enough to be useful and not well enough to be a rule, so our comparisons put two compounds on the same rows instead of describing each one on its own page and leaving you to line them up.
Cagrilintide sits outside the pattern. It is an amylin analogue — a different hormone system — and it turns up paired with semaglutide rather than measured against it. Orforglipron is the other odd one out — a small molecule taken by mouth, which rewrites the manufacturing economics of the whole category if it holds up.
The ladder is the protocol
Every approved incretin protocol titrates. The nausea and the rest of the gastrointestinal effects track the dose, and they subside as the body adapts, so the trials climbed in steps over months to reach the doses people now quote.
That is the part that gets lost in the retelling. A headline dose is where a protocol finished, not where it began. Semaglutide's approved weight-management schedule spends sixteen weeks getting there. Someone who reads the maintenance number and starts at it has skipped the four months that made it tolerable.
It is also why a compound page here shows a schedule and not a figure.
What is actually in the vial
An approved brand, a compounded preparation from a pharmacy, and a vial labelled for research are three different regulatory objects. On a bench they look the same. The regulatory line on each profile carries a date and names a jurisdiction, because the answer moves on both axes and a page that says only "legal" is telling you nothing.
Price is where the gap shows up hardest, and not in the direction people expect. We rank on price per milligram, not the price of a vial. Vial sizes across this category vary by more than a factor of ten, and the sticker price hides it completely.
Read next
Head to headSemaglutide vs liraglutideSame receptor, same drug class, one generation apart. One is a weekly injection and produced about twice the weight reduction of the other, which is a daily one.Head to headRetatrutide vs semaglutideOne receptor against three, and a finished approval against a trial programme still running. The largest reported effect in the class, set beside the most established one.Head to headSemaglutide vs cagrilintideTwo different satiety pathways, usually discussed as a pair rather than a choice. One is an approved drug on its own; the other is mostly studied alongside it.Head to headTirzepatide vs survodutideTwo dual agonists that picked different second receptors, GIP in one case and glucagon in the other, and that sit at very different stages of evidence.StackRetatrutide with MOTS-cA triple incretin agonist next to a mitochondrial peptide, on the argument that losing weight fast is easier than losing it well. The second half has never finished a human trial.StackA GLP-1 with 5-Amino-1MQAn incretin agonist doing the established work, with an oral NNMT inhibitor added on a mechanism that has never been tested in a person. One half of this has phase 3 trials; the other half has mice.GuideTitrating a dose: why you climb, and how to know when to stopEvery approved incretin protocol climbs in steps instead of starting at the target dose. Here is the reasoning behind that, and the one mistake that breaks a schedule.GuideTravelling with peptidesTemperature, paperwork, and the fact that legal status changes when you cross a line on a map. Two of those have practical answers.GuideStoring peptides properlyDry powder and mixed solution have completely different shelf lives. The clock that matters starts when you add water.
Common questions
- What is the difference between a GLP-1 agonist and a dual or triple agonist?
- The number is how many gut-hormone receptors the molecule acts at. Semaglutide acts at GLP-1 alone. Tirzepatide adds GIP. Retatrutide adds glucagon as well. Across trials, hitting more receptors has generally produced more average weight loss, along with a different side-effect picture.
- Is compounded semaglutide the same as the branded medicine?
- Not as a regulator sees it. An approved product has been assessed for quality, safety and efficacy as it is actually manufactured. A compounded or research-labelled preparation has not, whatever molecule is meant to be inside. Our compound pages carry a dated regulatory status for a named jurisdiction instead of a general reassurance.
- Why do these protocols start at a dose that does nothing?
- Because the side effects track the dose and fade with exposure. Climbing in steps is how the trials reached doses that would have been intolerable taken cold. Our titration guide covers the reasoning and the two mistakes that wreck a schedule.
- What happens when you stop?
- Follow-up has consistently shown weight coming back after discontinuation. Which is why these are studied as ongoing treatment rather than as a course you finish. If something was prescribed to you, stopping it is a conversation with whoever prescribed it, not a protocol question.
Last updated 21 Aug 2026