"Best" is two questions wearing one word. Which of these drugs takes the most weight off, and which of them can you actually afford to be on for the year or more it takes. The first has a clear answer now. The second depends on your insurance and your bank balance, and it can flip the first. This page ranks them both ways and then shows where the two lists cross.
What is actually on the list
Four branded products, two molecules, and one cheap version of each.
| Product | Molecule | Approved for | Form |
|---|---|---|---|
| Zepbound | tirzepatide | obesity, sleep apnoea | weekly injection |
| Mounjaro | tirzepatide | type 2 diabetes | weekly injection |
| Wegovy (pen, HD pen, tablet) | semaglutide | obesity, cardiovascular risk | weekly injection or daily pill |
| Ozempic | semaglutide | type 2 diabetes | weekly injection |
| Compounded tirzepatide | tirzepatide | not FDA-approved | injection, some oral |
| Compounded semaglutide | semaglutide | not FDA-approved | injection, some oral |
Two of the four brands are diabetes products. Lilly says it in plain words about one of them: "Mounjaro is not a weight loss drug."6 So the branded weight-loss list is really two products, Zepbound and Wegovy, and the question of which molecule is better is the question of Zepbound versus Wegovy. We cover the diabetes twins separately in Zepbound vs Mounjaro and Wegovy vs Ozempic.
Ranked by weight lost
This ranking rests on two trials, both published in 2025, both large, both run for 72 weeks.
1. Tirzepatide, 10 to 15 mg: 20.2%. SURMOUNT-5 was the first head-to-head. It gave 751 adults with obesity the highest dose of tirzepatide or semaglutide they could tolerate and measured them at 72 weeks. Tirzepatide took off 20.2% of body weight against semaglutide's 13.7%.1 That is the single most important number on this page: the only direct comparison, and a 6.5-point gap.
2. Semaglutide, 7.2 mg (Wegovy HD): 18.7%. STEP UP tested Novo's new high dose against the standard 2.4 mg and against placebo in 1,407 adults. The 7.2 mg dose lost 18.7%, the 2.4 mg dose 15.6%, placebo 3.9%.2 The high dose closes most of the gap to tirzepatide, though it has not been run against tirzepatide directly. We cover it in Wegovy 7.2 mg.
3. Semaglutide, 2.4 mg (Wegovy pen): 13.7% to 15.6%. The number depends on which trial you read: 13.7% as the comparator in SURMOUNT-5,1 15.6% as the comparator in STEP UP.2 Different populations, same drug, same dose. Either way it is the floor of the injectable branded options and still a large amount of weight.
4. The pills. Wegovy's tablet is "the only semaglutide tablet that's FDA-approved for weight loss".5 Its trial programme is separate and we have not captured a head-to-head figure to quote, so it sits below the injections here on the principle that a number we cannot quote does not get a rank. Its case is convenience and price, covered in every GLP-1 pill.
Where compounded sits. Compounded tirzepatide and semaglutide are the same molecules, so the evidence for the molecule is the evidence for the compound, at the same dose. What they lack is FDA review of the finished product. They rank where their molecule ranks, with that caveat attached.
Ranked by what you pay
Now the other list, from cheapest up, each price read from the seller's own page today.
| Route | Per month | Source |
|---|---|---|
| Compounded semaglutide | from $69 | our board, cheapest verified seller |
| Compounded tirzepatide | from $119 | our board, cheapest verified seller |
| Wegovy tablet | $149 to $299 by dose | Novo direct4 |
| Zepbound, 2.5 mg starting dose | $299 | Lilly direct3 |
| Wegovy pen, any standard dose | $349 | Novo direct4 |
| Wegovy HD pen, 7.2 mg | $399 | Novo direct4 |
| Zepbound, 5 / 7.5 mg | $399 / $499 | Lilly direct3 |
| Zepbound, 10 to 15 mg | $699 | Lilly direct3 |
| Either brand, commercial plan that covers it | $25 | maker's card3 |
Match the doses to the results. The 20.2% came from tirzepatide at 10 to 15 mg, the $699 tier. The 18.7% came from semaglutide 7.2 mg, the $399 pen. The 13.7% to 15.6% came from semaglutide 2.4 mg, the $349 pen. Ranked by weight lost per dollar of cash price, the order is very nearly the reverse of the ranking by weight lost.
And the live board, which is where the compounded prices above come from:
Where the two lists cross
There is no single best. There are four, one per situation.
Insured, and your plan covers Zepbound or Wegovy
Zepbound. Both makers' cards bring a covered drug to $25 a month for commercially insured patients.3 At the same price, take the drug that lost 20.2%. Whether your plan covers either is plan-specific; the coverage sheets quote eight insurers' own documents, and if you are refused, the appeal guide is next.
Paying cash, results first
Zepbound direct at $699, or compounded tirzepatide from $119. Same molecule, same trial evidence, one has FDA review of the finished product and one does not. That trade is the whole difference, and it is worth roughly $7,000 a year. Zepbound without insurance prices every dose; how to check a seller is the other half of the compounded route.
Paying cash, budget first
Compounded semaglutide from $69, or the Wegovy tablet from $149. Semaglutide at 13.7% to 15.6% is not the winner but it is a large result, and $69 to $149 a month is a commitment most people can sustain for the year it takes. The tablet is the cheapest FDA-approved route into the whole category.
Will not inject
The Wegovy tablet. Only one branded weight-loss product is a pill, and it is this one. Some compounded programs also sell semaglutide and tirzepatide as tablets or lozenges; the oral semaglutide board ranks them.
What does not change between them
Side effects. Every drug on this page slows the stomach, and every label lists the same family: nausea, diarrhoea, vomiting, constipation, stomach pain, tiredness. The rate tracks the dose and the speed of the climb, not the brand, and the head-to-head found nothing new separating the molecules. We have the label percentages, drug by drug, in GLP-1 constipation, nausea and diarrhoea.
The honest summary
Tirzepatide is the best GLP-1 for weight loss and semaglutide is the best value, and the distance between those two statements is about $350 a month at cash prices and zero dollars with coverage. Find out which of the four situations above is yours before you decide which drug is best, because the answer changes with the situation, and the drug does not.