Best GLP-1 for Weight Loss: The Approved Options Compared
The best GLP-1 for weight loss by trial results: Zepbound, Wegovy, the Wegovy pill, Foundayo and Saxenda compared on weight loss, side effects and self-pay price.
The short version
Ranked by average weight loss in their main trials, tirzepatide (Zepbound) comes first. Next come high-dose and standard semaglutide (Wegovy), the Wegovy pill, orforglipron (Foundayo) and liraglutide (Saxenda). In the one head-to-head trial, tirzepatide beat semaglutide. All are prescription medicines; "best" here means the trial results, not what suits one person.
- Zepbound (tirzepatide) had the largest average weight loss in its main trial: 20.9% at the top dose over 72 weeks.
- In a 72-week head-to-head trial, tirzepatide gave 20.2% weight loss against 13.7% on semaglutide.
- Side-effect rates come from separate trials, so they cannot rank the drugs; nausea is the most common for all of them.
- Self-pay prices on 3 October 2026 ran from $149 a month (starting-dose pills) to $699 (top-dose Zepbound without the refill offer).
Ranked by average weight loss in each drug’s main trial, tirzepatide (Zepbound) comes first. It gave 20.9% at its top dose over 72 weeks, against 3.1% on placebo Jastreboff 2022 - Jastreboff AM, Aronne LJ, Ahmad NN et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216., in the references below. It also beat semaglutide in the one head-to-head trial, 20.2% against 13.7% Aronne 2025 - Aronne LJ, Horn DB, le Roux CW et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025;393(1):26-36., in the references below.
“Best” on this page means the size of the trial result. The figures are group averages from separate trials with different people and lengths, so only the head-to-head trial compares two drugs directly. Which drug suits one person depends on their health, other medicines, tolerance and cost. That is a prescriber’s decision.
The approved GLP-1 options for weight loss, compared
| Drug (brand) | Average weight loss in its main obesity trial | How often | Form | Molecule first approved (US) | Self-pay price, 3 October 2026 |
|---|---|---|---|---|---|
| Tirzepatide (Zepbound) | 20.9% at 15 mg vs 3.1% on placebo, 72 weeks Jastreboff 2022 - Jastreboff AM, Aronne LJ, Ahmad NN et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216., in the references below | Once a week | Injection: vial, KwikPen or single-dose pen | 2022 | $299 to $449 a month (vial or KwikPen, by dose, with refills within 45 days) |
| Semaglutide 7.2 mg (Wegovy HD) | 18.8% vs 3.9% on placebo, 72 weeks (label) | Once a week | Injection pen | 2017 | $399 a month |
| Semaglutide 2.4 mg (Wegovy) | 14.9% vs 2.4% on placebo, 68 weeks Wilding 2021 - Wilding JPH, Batterham RL, Calanna S et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989-1002., in the references below | Once a week | Injection pen | 2017 | $349 a month ($199 for two intro fills for new patients) |
| Oral semaglutide 25 mg (Wegovy pill) | 13.6% vs 2.4% on placebo, 64 weeks (label) | Once a day | Tablet | 2017 | $149 to $299 a month, by dose |
| Orforglipron (Foundayo) | 11.1% at 17.2 mg vs 2.1% on placebo, 72 weeks (label) | Once a day | Tablet | 2026 | $149 to $349 a month, by dose |
| Liraglutide (Saxenda) | 7.4% vs 3.0% on placebo, 56 weeks (label) | Once a day | Injection pen | 2010 | No price on Novo’s page; Novo is discontinuing Saxenda, with last shipments in late January 2027 |
Every product in the table is a prescription medicine approved in the US to reduce excess body weight and keep it off, alongside diet and exercise.
Prices come from Lilly’s and Novo Nordisk’s own pages. The full price breakdown is on cheapest tirzepatide and semaglutide. Every price we checked, with its source, is in the GLP-1 cash price tracker.
Ozempic and Mounjaro are the same molecules as Wegovy and Zepbound, but they are approved for type 2 diabetes, not weight loss.
Which GLP-1 is best for weight loss, and which is faster?
On average weight loss, tirzepatide is first. In SURMOUNT-5, 751 adults with obesity and no type 2 diabetes took the highest dose they tolerated of tirzepatide or semaglutide for 72 weeks. Weight fell 20.2% on tirzepatide and 13.7% on semaglutide Aronne 2025 - Aronne LJ, Horn DB, le Roux CW et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025;393(1):26-36., in the references below. The trial was open-label and funded by Eli Lilly, which makes tirzepatide.
No trial was designed to compare speed. Each drug starts at a low dose and is raised in steps over weeks to months to limit stomach side effects. The averages above were measured after 56 to 72 weeks.
Which is better, Wegovy or Zepbound?
For weight loss, Zepbound did better in the head-to-head trial above. The other differences are in what each is approved for, its forms and its price:
| Wegovy (semaglutide) | Zepbound (tirzepatide) | |
|---|---|---|
| Weight loss in main trial | 14.9% (2.4 mg, 68 weeks); 18.8% (7.2 mg, 72 weeks) | 20.9% (15 mg, 72 weeks) |
| Other approvals | Lowering heart attack and stroke risk in adults with cardiovascular disease and obesity or overweight; MASH liver disease (injection only) | Obstructive sleep apnoea with obesity |
| Forms | Weekly pen, or daily tablet | Weekly vial, KwikPen or single-dose pen |
| Self-pay, 3 October 2026 | $349 pen, $399 HD pen, $149 to $299 pill | $299 to $449 vial or KwikPen |
More detail: semaglutide vs tirzepatide.
Which GLP-1 has the fewest side effects?
No trial ranks them. Each label reports its own rates, from separate trials with different placebo groups:
| Drug and dose | Nausea (drug vs placebo) | Stopped because of side effects (drug vs placebo) |
|---|---|---|
| Zepbound 15 mg | 28% vs 8% | 6.7% vs 3.4% |
| Wegovy 2.4 mg | 44% vs 16% | 6.8% vs 3.2% |
| Wegovy HD 7.2 mg | 39% vs 13% | 5% vs 2% |
| Foundayo 17.2 mg | 35% vs 10% | 10% vs 3% |
| Saxenda 3 mg | 39.3% vs 13.8% | 9.8% vs 4.3% |
Nausea on placebo ranged from 8% to 16%, which is why these numbers cannot be lined up as a ranking. In the head-to-head trial, stomach side effects were the most common in both groups. They were mostly mild to moderate and mostly came while the dose was being raised Aronne 2025 - Aronne LJ, Horn DB, le Roux CW et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025;393(1):26-36., in the references below.
What is the safest GLP-1 to take?
No trial has ranked them on safety, and the answer depends on the person. The labels of all four brands above (Zepbound, Wegovy, Foundayo and Saxenda) carry a boxed warning about thyroid C-cell tumours, based on rodent findings with GLP-1 drugs. All four are ruled out with a personal or family history of medullary thyroid cancer or MEN 2.
What differs is how long each molecule has been on the market. Liraglutide was first approved in 2010, semaglutide in 2017, tirzepatide in 2022 and orforglipron in 2026. A longer record means more years of use outside trials.
What is the number one weight loss injection?
By average weight loss in its main trial, Zepbound (tirzepatide), at 20.9% on the top dose. Wegovy HD (18.8%) and standard Wegovy (14.9%) follow. The daily injection, Saxenda, had the smallest effect, at 7.4%.
Best tirzepatide, best semaglutide: brand or compounded?
Two FDA-approved tirzepatide products exist, both from Eli Lilly: Zepbound for weight management and Mounjaro for type 2 diabetes. They contain the same molecule. For semaglutide, Wegovy (pen, HD pen or pill) is the weight-management brand. Ozempic (pen or pill) is for type 2 diabetes, and Novo says Rybelsus is being replaced by the Ozempic pill. The semaglutide pills compared: oral semaglutide. No tirzepatide pill is approved: tirzepatide pills.
Compounded tirzepatide and semaglutide are not FDA-approved, and research-labelled vials are not lawful medicines at all:
| Meaning of “GLP-1” | Status | How to think about it |
|---|---|---|
| FDA-approved GLP-1 and dual-incretin drugs | Prescription medicines | Labelled uses, risks and monitoring |
| Compounded versions | Narrow pharmacy compounding rules | Not FDA-approved; quality varies |
| Research-labelled products | Not approved for human use | FDA has warned sellers of these |
How to get each lawfully, with prices: tirzepatide online and semaglutide online.
US legal status - FDA-approved · prescription only
Several GLP-1 and dual-incretin products are FDA-approved prescription medicines with labelled indications, and access runs through a licensed prescriber. Compounded and "research-labelled" copies are not those products and do not inherit their approval.
AU legal status - TGA-registered · prescription only
Semaglutide and tirzepatide are both Schedule 4 of the Poisons Standard - prescription only - and registered products containing them are on the ARTG. Prescription medicines cannot lawfully be advertised to the Australian public, so an Australian reader being sold one of these directly is being sold it by someone breaking that rule.
Regulators reach their own conclusions on their own timelines. Where these two disagree, the difference is the point - not an error.
How GLP-1 drugs differ from research peptides
| Approved GLP-1 drugs | Typical research peptides | |
|---|---|---|
| Human trials | Extensive for labelled products | Often thin or absent |
| Manufacturing | Regulated drug supply chain | Research-chemical market |
| Legal status | Prescription | Not approved for human use |
| Sport / WADA | Check current list for your substance | Many research peptides banned |
See what are peptides? for the site’s three-bucket model.
Related
- Cheapest tirzepatide and semaglutide: compounded vs branded cost
- Semaglutide vs tirzepatide
- How GLP-1 medicines work
- Coming off a GLP-1: what happens when you stop
- Peptide telehealth: how legal prescribing works
- FDA-approved peptides: the complete list
- Peptide therapy
- Peptide injections
- Dosage calculator · How to reconstitute
- Peptide side effects
- Are peptides safe?
- Research peptides and the law
Common questions
Which GLP-1 is best for weight loss?
By average weight loss in the trials, tirzepatide (Zepbound): 20.9% at 15 mg over 72 weeks, against 3.1% on placebo. In the one head-to-head trial it gave 20.2% weight loss against 13.7% on semaglutide over 72 weeks. Which drug suits one person depends on their health, other conditions, tolerance and cost, which is a prescriber's decision.
Which GLP-1 works fastest?
No trial was designed to compare speed. Each drug starts at a low dose and is raised in steps over weeks to months to limit stomach side effects. The trial averages were measured after 56 to 72 weeks. Individual results vary with dose, starting weight and response.
What is better, Zepbound or Ozempic?
They are approved for different things. Ozempic is semaglutide approved for type 2 diabetes; Zepbound is tirzepatide approved for weight management and sleep apnoea with obesity. For weight, the head-to-head trial compared tirzepatide with semaglutide at Wegovy doses and found 20.2% against 13.7% weight loss at 72 weeks.
Which is better for weight loss, Ozempic or Mounjaro?
Neither is approved for weight loss; both are approved for type 2 diabetes. Mounjaro is the same molecule as Zepbound (tirzepatide) and Ozempic the same as Wegovy (semaglutide). The weight-loss brands carry the weight-management approval, and in their head-to-head trial tirzepatide gave more weight loss than semaglutide.
How long does it take to lose 20 pounds on a GLP-1?
No trial measured time to a set number of pounds. Weight loss in the trials built up gradually through the dose steps, and the headline averages were measured at 56 to 72 weeks. When one person reaches 20 pounds depends on starting weight, dose and response.
Which GLP-1 provider is best for weight loss?
I do not rank providers. A legitimate one screens you with a licensed clinician before prescribing. It prescribes an FDA-approved drug or a lawfully compounded version, fills it through a licensed pharmacy, and gives you a clinician to contact afterwards. FDA warns against sellers that skip screening, claim a compounded drug is the same as an approved one, or offer prices that seem too good to be true.
Are GLP-1 peptides the same as research peptides like BPC-157?
No. Approved GLP-1 drugs are prescription medicines with labelled uses and large trials. BPC-157 and similar compounds are unapproved research chemicals with a different evidence and legal profile.
Are compounded or unapproved GLP-1 products safe?
FDA does not review compounded drugs for safety, effectiveness or quality before sale. It reports dosing errors, counterfeit Ozempic, unapproved salt forms of semaglutide and products arriving warm. By 31 May 2026 it had received 990 adverse event reports for compounded semaglutide and more than 730 for compounded tirzepatide.
References (21 sources)
Bibliographic detail is fetched from PubMed, not written by me - so a citation here cannot drift from the paper it names. Study design comes from PubMed's own tags rather than my judgement.
- 1.Jastreboff AM, Aronne LJ, Ahmad NN et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216.Randomised trialPMID 35658024
- 2.Wilding JPH, Batterham RL, Calanna S et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989-1002.Randomised trialPMID 33567185
- 3.Aronne LJ, Horn DB, le Roux CW et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025;393(1):26-36.Clinical trialPMID 40353578
- 4.ZEPBOUND (tirzepatide) prescribing information: indications, dosage forms, 72-week weight results, adverse reaction rates, boxed warning and initial approval year.- DailyMed, National Library of Medicinelabel
- 5.WEGOVY (semaglutide) injection and tablets prescribing information: indications, Study 2 (68 weeks), Study 7 (25 mg tablet, 64 weeks), Study 8 (7.2 mg, 72 weeks), adverse reactions and boxed warning.- DailyMed, National Library of Medicinelabel
- 6.FOUNDAYO (orforglipron) tablets prescribing information: indication, once-daily dosing, Trial 1 weight results at 72 weeks, adverse reactions and boxed warning.- DailyMed, National Library of Medicinelabel
- 7.SAXENDA (liraglutide) prescribing information: indication, once-daily dosing, 56-week weight results, adverse reactions and boxed warning.- DailyMed, National Library of Medicinelabel
- 8.NovoCare Saxenda page: Novo Nordisk discontinuation notice, last shipments to wholesalers in late January 2027 (checked 3 October 2026).- Novo Nordisk Inc.other
- 9.Zepbound savings and self-pay page: regular KwikPen prices by dose and the $449 offer with refills within 45 days (checked 3 October 2026).- Eli Lilly and Companyother
- 10.Lilly pricing information for Zepbound: direct-to-patient self-pay prices by dose for vials and KwikPens (checked 3 October 2026).- Eli Lilly and Companyother
- 11.What to pay for Wegovy: self-pay prices for the Wegovy pill, pen and HD pen (checked 3 October 2026).- Novo Nordisk Inc.other
- 12.Foundayo coverage and savings page: regular self-pay prices by dose, temporary reductions and the refill offer (checked 3 October 2026).- Eli Lilly and Companyother
- 13.openFDA Drugs@FDA query for tirzepatide: two applications, both Eli Lilly NDAs (Mounjaro and Zepbound), checked 3 October 2026.- US Food and Drug Administrationdatabase
- 14.NovoCare Rybelsus page: Rybelsus is being replaced by the Ozempic pill (checked 3 October 2026).- Novo Nordisk Inc.other
- 15.FDA - FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (updated 1 October 2026): adverse event counts, dosing errors, counterfeits, salt forms and telehealth red flags.- US Food and Drug Administrationregulatory
- 16.FDA - bulk drug substances used in compounding under section 503A.- US Food and Drug Administrationregulatory
- 17.21 U.S.C. §321 - drug definition under the FD&C Act.- Cornell Legal Information Institutestatute
- 18.Therapeutic Goods (Poisons Standard - June 2026) Instrument 2026, the current Poisons Standard (SUSMP). Semaglutide and tirzepatide are both Schedule 4 - prescription only - in Australia.- Federal Register of Legislation, Australian Governmentstatute
- 19.ARTG 315107 - OZEMPIC 1 mg semaglutide (rys) solution for injection pre-filled pen. Registered medicine, sponsor Novo Nordisk Pharmaceuticals Pty Ltd, ARTG date 28 August 2019.- Therapeutic Goods Administration, Australian Governmentdatabase
- 20.ARTG 407050 - MOUNJARO tirzepatide 5 mg/0.5 mL solution for injection vial. Registered medicine, sponsor Eli Lilly Australia Pty Ltd, ARTG date 10 July 2023.- Therapeutic Goods Administration, Australian Governmentdatabase
- 21.TGA - What can and cannot be advertised to the general public. Prescription-only medicines and substances cannot be advertised to the Australian public, and neither can unapproved therapeutic goods.- Therapeutic Goods Administration, Australian Governmentregulatory