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New in
AOD-9604
AOD-9604 is a modified 16-residue fragment of human growth hormone, studied in fat-metabolism and cartilage research,…
- Research Peptides
- Weight Management
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New in
Cagrilintide
Cagrilintide is a long-acting, lipidated amylin analogue studied in obesity and type 2 diabetes research, including…
- Research Peptides
- Weight Management
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New in
Retatrutide
Retatrutide (LY3437943) is a triple GIP, GLP-1 and glucagon receptor agonist peptide, supplied as freeze-dried powder…
- Peptides for Women
- Research Peptides
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Semaglutide
Semaglutide is a long-acting, lipidated GLP-1 analogue peptide, supplied as freeze-dried powder in 5 mg, 10…
- Peptides for Women
- Research Peptides
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New in
Tirzepatide
Tirzepatide (LY3298176) is a dual GIP and GLP-1 receptor agonist peptide, supplied as lyophilized powder in…
- Peptides for Women
- Research Peptides
Weight loss peptides compared
Each headline is the largest published trial cited on the product page; percentages are mean body-weight changes with clinical formulations. Prices are the lowest listed at the time of writing.
| Compound | Receptor targets | Largest trial headline | Women enrolled | Vial sizes | Listed from (USD) |
|---|---|---|---|---|---|
| Retatrutide | GIP, GLP-1 and glucagon receptors in one molecule | TRIUMPH-1: 2,339 adults without diabetes; −17.6% to −25.0% vs −3.9% with placebo at 80 weeks (Jastreboff et al., 2026) | 163 in phase 2; 554 in TRIUMPH-2 | 5, 10, 30, 50, 60 mg | $33.50 |
| Tirzepatide | GIP and GLP-1 receptors | SURMOUNT-1: 2,539 adults; −15.0% to −20.9% vs −3.1% at 72 weeks (Jastreboff et al., 2022) | 67.5% of participants | 10, 15, 20, 30, 60 mg | $100.00 |
| Semaglutide | GLP-1 receptor | STEP 1: 1,961 adults; −14.9% vs −2.4% at 68 weeks (Wilding et al., 2021) | 74.1% of participants | 5, 10, 20, 30 mg | $60.00 |
| Cagrilintide | Amylin and calcitonin receptors | Phase 2: 706 adults; −6.0% to −10.8% vs −3.0% at 26 weeks (Lau et al., 2021) | 436 of 706 | 5, 10 mg | $74.45 |
| AOD-9604 | Modified growth-hormone fragment (177–191 plus tyrosine) | OPTIONS: under 1 kg extra loss vs placebo, not significant; program stopped (sponsor, 2007) | 56% of 502 in a 24-week safety trial | 10 mg | $110.00 |
GLP-1, GIP, glucagon and amylin: what the targets mean
GLP-1 and GIP are gut-hormone signaling systems involved in glucose regulation and food intake. Semaglutide activates the GLP-1 receptor; a lipid attachment promotes binding to the blood protein albumin, linked to its prolonged action (Lau et al., 2015). Tirzepatide activates GIP and GLP-1 receptors within one peptide, with a preference for cAMP signaling at the GLP-1 receptor in cell assays (Willard et al., 2020).
Retatrutide adds glucagon-receptor activity. In obese mice, that third target added higher energy expenditure to the reduced food intake associated with GIP/GLP-1 activity (Coskun et al., 2022). Cagrilintide takes a different route: it is a lipidated, long-acting amylin analogue (Kruse et al., 2021), and structural work mapped it bound to three amylin receptor types and the calcitonin receptor (Cao et al., 2025).
Retatrutide vs tirzepatide vs semaglutide
No published trial compares all three, so the table’s numbers should not be ranked: populations, durations and statistical approaches differ. In SURMOUNT-5, 751 adults with obesity lost a mean 20.2% with tirzepatide versus 13.7% with semaglutide at 72 weeks (Aronne et al., 2025). In October 2026, Lilly reported that TRANSCEND-T2D-2, an open-label trial of 1,298 adults with type 2 diabetes, found weight changes of −19.5% to −20.9% with retatrutide versus −9.4% with semaglutide 2 mg over 80 weeks; those figures were awaiting journal publication (Lilly announcement).
Cagrilintide and AOD-9604: different mechanisms, different evidence
Much of cagrilintide’s large-trial evidence comes from CagriSema, a combination with semaglutide. In REDEFINE 1, the combination produced an estimated −20.4% weight change versus −3.0% with placebo at 68 weeks (Garvey et al., 2025). Those results cannot be assigned to the cagrilintide-only vial listed here.
AOD-9604 shows why fat-loss mechanisms need human confirmation. Obese mice gained less weight and showed increased fat oxidation without the GH-receptor binding seen with intact hormone (Heffernan et al., 2001), yet the developer’s larger human trial found no significant weight advantage over placebo.
Women in weight-management research
Women formed the majority in several landmark trials: 74.1% of STEP 1 (participant data) and 67.5% of SURMOUNT-1 (participant data). The cagrilintide phase 2 register lists 436 women among 706 participants. A prespecified subgroup analysis of the retatrutide phase 2 trial reported greater percentage weight reduction in women than in men (Jastreboff et al., 2023). Other compounds appear in the peptides for women hub.
Weight loss peptides FAQ
Which peptides are studied for weight loss?
The best-documented are semaglutide, tirzepatide and retatrutide, each tested in large randomized obesity trials of clinical formulations. Cagrilintide has phase 2 data alone and larger trials in combination with semaglutide. AOD-9604 produced fat-oxidation findings in mice but did not beat placebo significantly in the developer’s human trial.
What is the difference between retatrutide, tirzepatide and semaglutide?
The difference is receptor coverage. Semaglutide targets GLP-1 receptors; tirzepatide targets GIP and GLP-1 receptors; retatrutide targets GIP, GLP-1 and glucagon receptors, all within single molecules rather than blends. Each was tested in different trial programs, so their headline weight changes are not directly comparable without a head-to-head study.
What is a GLP-1 peptide?
It is a peptide that activates the receptor for glucagon-like peptide-1, a gut hormone involved in glucose regulation and appetite signaling. Semaglutide is a modified GLP-1 analogue with a fatty attachment that binds albumin and prolongs its action. Tirzepatide and retatrutide also act at GLP-1 receptors alongside other targets.
What is a triple agonist peptide?
A triple agonist is a single molecule that activates three receptor types. Retatrutide is the example in this catalog: one 39-amino-acid modified peptide active at GIP, GLP-1 and glucagon receptors. It is not a mixture of three peptides; receptor assays found its activity was strongest at the GIP receptor.
What side effects were reported in GLP-1 trials?
Gastrointestinal adverse events were the most common pattern across these trials. Retatrutide’s phase 2 trial also reported heart-rate increases that peaked at week 24 before declining, and TRIUMPH-2 recorded more low blood pressure and altered skin sensations (TRIUMPH-2). These findings describe clinical formulations.
Related categories: All research peptides · Peptides for women · Energy & metabolic peptides. For laboratory research only. Not for human or veterinary use.
