Best peptides for weight loss in 2026, ranked
Last updated November 10, 2026
Six compounds, two molecules, one scoring system. Here is how the US Peptide Labs weight category stacks up this month.
The ranking
GLP-3RT Vial
★★★★★4.8/5 editorial scoreThe compound behind the biggest weight-trial numbers of the decade. Three receptors, one molecule, 13 lots with a COA on file.
GLP-2T Vial
★★★★★4.7/5 editorial scoreThe dual-agonist molecule with the deepest published record: 72-week data, a head-to-head win and the lowest price per mg in the catalog.
GLP-3RT Nasal Spray
★★★★☆4.2/5 editorial scoreSame triple-agonist compound in a pre-mixed nasal format. Convenient, but the published trials all used a different route.
GLP-2T Nasal Spray
★★★★☆4.2/5 editorial scoreThe dual agonist in a nasal spray. A smaller 20 mg version at $145 exists but was sold out at our last check.
GLP-3RT Oral Spray
★★★★☆4.1/5 editorial scoreTriple agonist as an oral spray. The easiest format to handle, with the least published route data behind it.
GLP-2T Oral Spray
★★★★☆4.1/5 editorial scoreThe lowest-priced spray in the weight category. Dual agonist, oral spray format.
How we ranked
Each compound gets a score out of 5 on four criteria, weighted equally: whether a lot-specific outside lab certificate exists, how much published human evidence stands behind the molecule and the format, what a milligram costs after volume tiers, and how it ships. Vials beat sprays on evidence because every published trial used injection.
Average body-weight change at the top studied dose. Sources: STEP 1 (NEJM 2021), SURMOUNT-1 (NEJM 2022), retatrutide phase 2 (NEJM 2023). Separate trials, not a head-to-head comparison.
Summary table
| # | Compound | Score | From | Why |
|---|---|---|---|---|
| 1 | GLP-3RT Vial | 4.8/5 | $100.00 | Top pick |
| 2 | GLP-2T Vial | 4.7/5 | $76.00 | Best value |
| 3 | GLP-3RT Nasal Spray | 4.2/5 | $220.00 | Needle-free |
| 4 | GLP-2T Nasal Spray | 4.2/5 | $220.00 | Needle-free |
| 5 | GLP-3RT Oral Spray | 4.1/5 | $220.00 | Needle-free |
| 6 | GLP-2T Oral Spray | 4.1/5 | $145.00 | Lowest spray price |
FAQ
What is the best peptide for weight loss in 2026?
On published trial averages the triple agonist retatrutide leads, at -24.2% over 48 weeks in phase 2. The dual agonist tirzepatide has the longer and larger record at -20.9% over 72 weeks.
Vial or spray?
All published trial results come from weekly subcutaneous injection. Spray formats are more convenient but have no published human route data, so we rank vials higher.
How were these ranked?
Editorial scores on four fixed criteria: purity documentation, published evidence, price per mg and shipping. Reviewed by a registered dietitian.