If you have been reading about peptides and weight, you have probably hit a wall of acronyms — GLP-1, GIP, glucagon, amylin — with nobody explaining what any of them mean. This guide fixes that. No jargon, no hype, and an honest account of where the evidence actually stands.
The short version
Most weight-related peptides work by copying signals your body already makes — the hormones that tell your brain you have eaten enough. They are not stimulants. They are not fat burners in the old sense. They are copies of your own biology, and they mostly work on appetite.
First, three words worth knowing
| Word | What it means |
|---|---|
| Peptide | A short chain of amino acids. Like a very small protein. |
| Agonist | Something that switches a body signal on. A "dual agonist" flips two switches; a "triple agonist" flips three. |
| Receptor | A lock on the surface of a cell. The right molecule is the key that fits it. |
The GLP-1 family, in order of how many switches they flip
| Compound | Signals copied | Also known as | Status |
|---|---|---|---|
| Semaglutide | GLP-1 | Ozempic, Wegovy | Approved for specific uses |
| Tirzepatide | GLP-1 + GIP | Mounjaro, Zepbound | Approved for specific uses |
| Survodutide | GLP-1 + glucagon | — | Investigational |
| Mazdutide | GLP-1 + glucagon | — | Investigational |
| Retatrutide | GLP-1 + GIP + glucagon | "Triple G" | Investigational |
| Cagrilintide | Amylin | — | Investigational |
| CagriSema | Amylin + GLP-1 | — | Investigational |
What each signal actually does
- GLP-1 — the "I'm full" signal. Slows how fast the stomach empties and reduces appetite. This is the backbone of the whole category.
- GIP — a second gut hormone involved in blood sugar handling and fat storage. Adding it to GLP-1 has generally produced larger effects in trials than GLP-1 alone.
- Glucagon — the outlier. While the first two mostly reduce intake, glucagon is associated with the body using more of the fuel it already has.
- Amylin — a separate fullness signal that also slows stomach emptying. Studied on its own and paired with GLP-1.
The trade-off nobody states plainly
There is an inverse relationship running through that table, and it is the single most useful thing to understand:
The compound with the most mechanisms has the least long-term human data. The compound with the most data has the fewest mechanisms.
Semaglutide has years of published evidence and one mechanism. Retatrutide has three mechanisms and the shortest track record. "Newer" and "better established" point in opposite directions here — and which matters more depends entirely on the question being asked.
Beyond the GLP-1 family
Several other compounds get grouped into weight and metabolism research for different reasons.
| Compound | Studied around | Evidence stage |
|---|---|---|
| AOD-9604 | Fat metabolism — a fragment of growth hormone | Investigational, limited human data |
| HGH Fragment 176-191 | Fat metabolism, closely related to AOD-9604 | Early research |
| Tesamorelin | Visceral (deep abdominal) fat specifically | Approved for a specific medical use |
| MOTS-c | Mitochondrial signalling, energy use, insulin sensitivity | Mostly lab and animal |
| 5-Amino-1MQ | An enzyme (NNMT) involved in fat-cell energy storage | Lab and animal |
| SLU-PP-332 | "Exercise mimic" — energy expenditure without exercise | Animal studies |
What the research does not show
Three honest limits worth holding onto:
- Investigational means unfinished. Retatrutide, survodutide, mazdutide and cagrilintide are still moving through trials. Encouraging trial results are not the same as an established long-term safety record.
- Animal data is a starting point, not a conclusion. MOTS-c, 5-Amino-1MQ and SLU-PP-332 are early-stage. The distance between "consistent effect in mice" and "proven in people" is enormous, and most overclaiming lives in that gap.
- More mechanisms is not automatically better. Every pathway a compound touches is also a pathway where unintended effects can occur. That is precisely why trials take years.
Frequently asked questions
What is the strongest peptide for weight loss?
In published trials, retatrutide has produced the largest average weight reductions reported for this class. It is also the least established — still investigational, with the shortest safety record of the group.
What is the difference between semaglutide and tirzepatide?
Semaglutide copies one signal (GLP-1). Tirzepatide copies two (GLP-1 and GIP). Both are approved for specific uses in several countries; tirzepatide has generally shown larger average effects in head-to-head research.
Are these the same as fat burners?
No. Traditional fat burners were typically stimulants that raised heart rate and metabolic rate. GLP-1 family compounds copy natural appetite hormones and work primarily by reducing how much you want to eat.
What does "investigational" mean?
It means the compound is still in clinical trials and has not been approved as a medicine. It is not a comment on whether the early results look promising — it is a statement about what has and has not yet been established.
Why do some of these have brand names and others don't?
Brand names appear after a compound is approved and marketed as a medicine. Semaglutide became Ozempic and Wegovy; tirzepatide became Mounjaro and Zepbound. Investigational compounds have no brand name because they have not reached that stage.
Keep reading
- What Is Retatrutide? The triple agonist explained
- Semaglutide vs Tirzepatide vs Retatrutide
- The Peptide Directory — every compound in plain English
- What "Research Use Only" actually means
Dissolv supplies these compounds for laboratory research only. They are not medicines as supplied by us, are not for human or veterinary consumption, and have not been evaluated by the FDA for safety or effectiveness in people. This article is educational and is not medical advice, dosing guidance, or a recommendation. Approval status varies by country and changes over time.
