Best peptides for weight loss, ranked by what the data actually shows.

What this list is, and what it is not

If you have searched for the best peptides for weight loss, you have probably noticed two things: every list ranks them differently, and almost none of them tell you the price. This one does both. We compare the compounds people actually research, explain how each one works in plain English, and show you the best live per-milligram price on our site so you can see where the value really sits.

One important framing first. The compounds below are sold as research peptides, not prescriptions. Clearly Peptides does not sell anything: we aggregate third-party vendor prices and real per-batch lab data so you can compare honestly. FDA-approved prescription versions of several of these molecules exist, and the weight-reduction figures you read about come from clinical trials of those pharmaceutical products, not from the research-grade material vendors list. Nothing here is medical advice. Talk to a clinician about anything you intend to put in your body.

Research use only. The prices shown are the best live listings across vendors we track, not endorsements. Always read the COA before you trust a batch.

How these actually work

Most of the modern weight-loss peptides are incretin mimics. They copy gut and pancreatic hormones that your body releases after you eat. The differences between them come down to which of these hormone pathways each one switches on.

GLP-1

GLP-1 (glucagon-like peptide-1) is the headline pathway. It slows how fast your stomach empties, blunts appetite signaling, and helps regulate blood sugar. This is the mechanism behind the original semaglutide molecule that made the category famous.

GIP

GIP (glucose-dependent insulinotropic polypeptide) is a second incretin hormone. On its own it is subtle, but paired with GLP-1 it appears to improve the overall response. Tirzepatide is the dual GLP-1 plus GIP agonist that put this combination on the map.

Glucagon

Glucagon is best known for raising blood sugar, but in this context it is being used for its effect on energy expenditure and fat metabolism. Triple and dual agonists that add a glucagon arm, like retatrutide, mazdutide and survodutide, are the newest and most aggressive designs in the class.

Amylin

Amylin is a separate satiety hormone. Cagrilintide is an amylin analog, and it is usually researched as a partner to a GLP-1 rather than a solo agent, which is why you see the CagriSema (cagrilintide plus semaglutide) combination discussed so often.

The ranked rundown

Here is the practical breakdown. In the prescription trials, the triple-agonist retatrutide showed the largest average weight reduction of this group, with tirzepatide ahead of semaglutide. We are deliberately speaking in relative terms here, because the magnitudes come from trials of the approved drugs, not the research material. All of them share dose titration and GI side effects, mainly nausea, in those trials.

1. Retatrutide

What it is: a triple agonist that hits GLP-1, GIP and glucagon at once. Why people pick it: in clinical trials it produced the largest average weight reduction of any compound in this group, which makes it the one researchers are most curious about right now. Best price on our site: $180 / 20 mg, which works out to $9/mg. See the retatrutide product page or the retatrutide guide.

2. Tirzepatide

What it is: the dual GLP-1 plus GIP agonist. Why people pick it: it sits ahead of semaglutide in the trial data and, notably, it is the cheapest per milligram of this entire group on our site. That combination of strong trial results and low cost makes it the value pick. Best price on our site: $94.99 / 30 mg, or $3.17/mg. See the tirzepatide product page or the tirzepatide guide.

3. Semaglutide

What it is: the original GLP-1 agonist, the molecule behind the names everyone knows. Why people pick it: it is the most studied and most familiar of the group, and it is the GLP-1 half of the popular CagriSema pairing. Best price on our site: $74.99 / 15 mg, or $5/mg. See the semaglutide product page or the semaglutide guide.

4. Cagrilintide

What it is: an amylin analog. Why people pick it: it is the satiety partner in the CagriSema combination rather than a standalone agent, so people researching it are usually building a pairing with semaglutide. Best price on our site: $89.99 / 10 mg, or $9/mg. See the cagrilintide product page.

5. Survodutide

What it is: a dual GLP-1 plus glucagon agonist. Why people pick it: it adds the glucagon arm for energy expenditure while staying a dual rather than triple agonist, and it is the more affordable of the two glucagon dual agonists we track. Best price on our site: $78 / 10 mg, or $7.8/mg. See the survodutide product page.

6. Mazdutide

What it is: another dual GLP-1 plus glucagon agonist. Why people pick it: the same glucagon-plus-GLP-1 rationale as survodutide, for researchers who want to compare the two designs. Best price on our site: $170 / 10 mg, or $17/mg, which makes it the most expensive per milligram here. See the mazdutide product page.

7. AOD-9604

What it is: a fragment of human growth hormone, marketed for fat metabolism. Why people pick it: it is outside the incretin class entirely and is weaker and less established than the GLP-1 family, so it tends to interest people looking for a non-GLP-1 angle. Set expectations accordingly. Best price on our site: $53 / 5 mg, or $10.6/mg. See the AOD-9604 product page.

The new oral pill: orforglipron (Foundayo)

Until recently, everything above had to be injected. Orforglipron changes that. It is the first oral (pill) GLP-1, and it was FDA-approved as Foundayo (Eli Lilly) in April 2026. Unlike older oral peptide attempts, it has no food or water timing restrictions, which makes it far more practical day to day.

If you want a swallowable, prescription option, this is the new alternative to ask a clinician about. For research-grade material, orforglipron is on the pricier end: the best listing we track is $198.95 / 6 mg. As always, the approved pill and the research compound are not the same thing, and the trial outcomes belong to the approved product.

How to not overpay

The single biggest mistake is comparing the sticker price instead of the price per milligram. A $94.99 vial and a $74.99 vial tell you nothing until you divide by the milligrams inside. On our data, tirzepatide at $3.17/mg is dramatically better value than mazdutide at $17/mg, even though mazdutide has the smaller-looking total. Always compare on a per-mg basis.

• Divide before you decide. Price per milligram is the only number that lets you compare vials of different sizes fairly.
• Check the COA. A cheap vial with no recent per-batch certificate of analysis is not actually cheap. You are paying for purity you cannot verify.
• Match the molecule to the question. Cagrilintide is a partner, not a solo act. AOD-9604 is not in the same weight class as the incretins. Pay for the right tool.

This is the whole reason the site exists. We pull live prices and real per-batch lab data so you can see, in one place, which vendor is actually offering the best deal on a verified batch right now.

And before you trust any single listing, open the lab data. Our lab data page shows the per-batch COA results so you are comparing verified material, not just numbers on a checkout page. Browse the full catalog on the peptides page.

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