The American Peptides GLP-1 & Metabolic catalog currently contains five research products: Semaglutide, Tirzepatide, Retatrutide, Cagrilintide, and Retatrutide + Cagrilintide. Listed starting prices currently run from $60 to $200, with the supplier describing the collection as research-use-only and emphasizing lot-matched COAs and third-party analytical testing.
For an eligible order, the current LOOT10 promotion is advertised as providing up to 30% off. Check the American Peptides LOOT10 offer
The important point is that these products are not simply five versions of the same peptide. They represent different molecular targets and different research questions.
The American Peptides GLP-1 catalog at a glance
The current American Peptides collection lists:
| Product | Research profile | Current listed starting price |
|---|---|---|
| Semaglutide | GLP-1 receptor agonist | $60 |
| Tirzepatide | GIP/GLP-1 dual agonist | $100 |
| Retatrutide | GIP/GLP-1/glucagon tri-agonist | $105 |
| Cagrilintide | Amylin-pathway research compound | $170 |
| Retatrutide + Cagrilintide | Combined metabolic research material | $200 |
These prices are a current catalog snapshot and can change. The American Peptides collection explicitly states that its products are for laboratory and research use only, not human or veterinary use.
The most useful way to organize the catalog is by receptor and pathway profile, not by price.
Why Semaglutide, Tirzepatide and Retatrutide are often compared
Semaglutide, Tirzepatide, and Retatrutide sit on a useful research continuum.
Semaglutide is classified as a GLP-1 receptor mono-agonist.
Tirzepatide is a GIP/GLP-1 dual agonist.
Retatrutide is a GIP/GLP-1/glucagon tri-agonist.
That gives researchers a straightforward conceptual progression:
Semaglutide → GLP-1
Tirzepatide → GIP + GLP-1
Retatrutide → GIP + GLP-1 + glucagon
The comparison is useful because it separates differences in receptor-target breadth from the much broader question of clinical efficacy. This guide is focused on the research properties of the catalog materials, not treatment recommendations.
For a dedicated structural comparison, see:
Semaglutide vs Tirzepatide vs Retatrutide: 2026 Receptor Differences
1. Semaglutide: the GLP-1-focused research compound
Semaglutide is the simplest starting point in the American Peptides metabolic catalog if the research question is centered on GLP-1 receptor biology.
The American Peptides compound comparison classifies Semaglutide as a synthetic, lipidated GLP-1 receptor agonist and lists it as a 31-amino-acid peptide. The same reference reports a molecular weight of approximately 4,113.58 Da and a catalog purity specification of ≥99% by HPLC with COA availability.
That makes Semaglutide useful as a relatively focused molecular model when the experimental question is about GLP-1R rather than multiple incretin and glucagon receptors simultaneously.
What makes Semaglutide useful for comparison studies?
It can serve as the single-receptor reference point.
That makes it easier to compare how research models change when additional receptor activity is introduced.
The conceptual sequence becomes:
GLP-1 only
versus
GLP-1 + GIP
versus
GLP-1 + GIP + glucagon
That is more informative than treating all three products as interchangeable.
Current Semaglutide price
American Peptides currently lists Semaglutide from $60.
Researchers comparing suppliers should check the selected quantity, current lot documentation, shipping terms, and final checkout price rather than comparing the $60 headline price alone.
2. Tirzepatide: the dual-agonist research model
Tirzepatide expands the research question by engaging both GIP and GLP-1 receptors.
American Peptides' current comparison reference describes Tirzepatide as a 39-amino-acid lipidated peptide with a listed molecular weight of approximately 4,813.45 Da. It is classified as a GIP/GLP-1 dual agonist.
This makes Tirzepatide particularly useful for research designs examining the difference between single-receptor and dual-receptor incretin signaling.
The key research distinction is:
Semaglutide: one principal incretin receptor target
Tirzepatide: two incretin receptor targets
That does not mean the additional receptor target automatically produces a predetermined biological outcome in every model. It means the molecular system being studied is different.
Current Tirzepatide price
The American Peptides GLP-1 & Metabolic catalog currently lists Tirzepatide from $100.
American Peptides also displays volume pricing on its Tirzepatide product page, so larger research purchases should be evaluated using the applicable quantity tier rather than only the first displayed price.
3. Retatrutide: the triple-agonist research model
Retatrutide adds another receptor dimension.
American Peptides classifies it as a GIP/GLP-1/glucagon tri-agonist, meaning the research material is designed around three receptor systems rather than one or two.
Its current product page lists the material from $105, and the catalog shows multiple quantity options.
For research, the appeal is clear: Retatrutide allows investigators to study a broader receptor-targeting architecture than Semaglutide or Tirzepatide.
Retatrutide as the third point on the receptor continuum
The most useful simplified comparison is:
| Compound | Receptor profile |
|---|---|
| Semaglutide | GLP-1R |
| Tirzepatide | GIPR + GLP-1R |
| Retatrutide | GIPR + GLP-1R + GCGR |
American Peptides describes these three compounds as part of a single structural design continuum within the glucagon/secretin superfamily, with receptor breadth being a principal differentiator.
That makes them natural candidates for comparative research.
Current Retatrutide pricing
The current American Peptides catalog lists Retatrutide from $105.
The product page also displays volume-price reductions, making it especially important to compare the effective per-unit price when evaluating larger legitimate research orders.
4. Cagrilintide: why it belongs in this catalog
Cagrilintide is different from the first three products because it shifts the research question away from the same incretin-receptor progression.
American Peptides describes Cagrilintide as a research peptide associated with the amylin pathway. It is currently listed at $170.
That makes it useful for a different type of research comparison.
Instead of:
GLP-1 → GIP/GLP-1 → GIP/GLP-1/glucagon
you can think about:
incretin signaling → amylin signaling
This distinction is important because product categories can sometimes make compounds appear more similar than they really are.
Why researchers may compare Cagrilintide with the incretin materials
The useful research question isn't "Which one is strongest?"
It is:
How does amylin-related signaling differ from incretin-related signaling, and how can those systems be studied independently or together?
That is a cleaner research framing.
5. Retatrutide + Cagrilintide: the combination product
American Peptides also lists a combined Retatrutide + Cagrilintide research product for $200.
This is important because it represents a different purchasing and experimental concept from an individual-compound study.
When researchers purchase individual compounds, they retain more control over the independent variables.
A combination material instead provides a predefined pairing.
That can be useful for a study designed specifically around combined pathway research, but it should not be assumed to be universally preferable.
What does "GLP-1" mean in a research catalog?
GLP-1 stands for glucagon-like peptide-1, an endogenous peptide involved in a complex signaling system.
In research contexts, scientists may study:
- receptor activation,
- receptor binding,
- signaling cascades,
- peptide structure,
- receptor selectivity,
- ligand design,
- peptide stability,
- molecular pharmacology,
- and interactions among metabolic pathways.
That is different from discussing a compound as a consumer weight-management product.
The American Peptides catalog itself explicitly keeps these materials within a research-use-only framework.
American Peptides GLP-1 catalog vs the broader product lineup
The five-product GLP-1 & Metabolic category sits inside a much broader American Peptides catalog.
The current site also lists a dedicated Research Peptides collection with products such as BPC-157, GHK-Cu, MOTS-C, TB-500, Selank, Semax, Ipamorelin, Tesamorelin, IGF-1 LR3, Thymosin Alpha-1, SS-31 and others.
That broader catalog matters for researchers whose work crosses metabolic signaling with other biological systems.
Rather than evaluating the GLP-1 category in isolation, a lab can examine whether a supplier's overall catalog is broad enough to support multiple research programs.
The research-focused way to choose between Semaglutide, Tirzepatide and Retatrutide
The strongest way to choose among the three is to identify the receptor question first.
Choose a GLP-1-focused model
Semaglutide is the most direct fit when GLP-1 receptor signaling is the central research variable.
Investigate dual incretin receptor signaling
Tirzepatide provides GIPR + GLP-1R activity for studies examining broader incretin receptor engagement.
Investigate triple-receptor signaling
Retatrutide adds glucagon-receptor activity, giving researchers a broader molecular model.
Investigate amylin-related signaling
Cagrilintide shifts the question to a different metabolic signaling pathway.
Examine a combined metabolic research material
Retatrutide + Cagrilintide provides the current combined catalog option.
This is more defensible than assigning a universal ranking.
American Peptides GLP-1 pricing in 2026
The current listed starting prices are:
| Product | Starting price |
|---|---|
| Semaglutide | $60 |
| Tirzepatide | $100 |
| Retatrutide | $105 |
| Cagrilintide | $170 |
| Retatrutide + Cagrilintide | $200 |
These figures should be treated as catalog snapshots.
Prices can change, inventory can change, and quantity tiers can alter the effective cost per unit.
For a more detailed pricing discussion, see:
American Peptides Price Guide 2026
How volume pricing changes the comparison
Looking only at the starting price can distort a supplier comparison.
Suppose one research project requires multiple units.
The relevant calculation becomes:
total order cost ÷ number of units = effective unit cost
not:
advertised starting price = final unit cost
American Peptides currently displays volume pricing on selected metabolic products. Researchers should therefore check the product-specific quantity table before comparing it against another supplier.
This is especially relevant to Retatrutide and Tirzepatide, where larger quantities can produce lower listed per-unit prices.
How LOOT10 fits into the price calculation
The current promotion supplied for this guide is LOOT10, advertised as offering up to 30% off eligible purchases.
Check the American Peptides LOOT10 offer
The exact discount should be confirmed at checkout.
"Up to 30% off" does not necessarily mean that every product or order receives a flat 30% reduction.
A useful comparison therefore remains:
catalog price → quantity discount → LOOT10 eligibility → shipping → final checkout
That is the number that matters.
A simple illustration of LOOT10 savings
For illustration only, if an eligible purchase received the full 30% reduction:
| Listed price | 30% reduction | Illustrative price |
|---|---|---|
| $60 | $18 | $42 |
| $100 | $30 | $70 |
| $105 | $31.50 | $73.50 |
| $170 | $51 | $119 |
| $200 | $60 | $140 |
These figures are arithmetic examples, not guaranteed checkout prices.
Always verify the promotion on the actual order.
Documentation: the part of the catalog worth checking closely
Price is only one part of research procurement.
American Peptides currently emphasizes:
- lot-matched Certificates of Analysis,
- HPLC analysis,
- mass spectrometry,
- third-party testing,
- and 99%+ purity claims for research-grade peptides.
The site also maintains a COA section that associates certificates with individual batches.
This is important because researchers need to distinguish between:
a general product claim
and
documentation tied to the exact material lot
The latter is much more useful for laboratory recordkeeping.
For a broader discussion of supplier comparison and documentation, see:
American Peptides vs Peptide Sciences Alternatives
How to evaluate a GLP-1 research peptide supplier
Before ordering any research compound, compare suppliers using the same criteria.
1. Identity
Can the supplier demonstrate that the material corresponds to the claimed compound?
2. Purity
What analytical method is being used, and what threshold is reported?
3. Lot traceability
Can the results be associated with the actual batch being purchased?
4. Analytical documentation
Is a COA available and sufficiently detailed for your laboratory's requirements?
5. Quantity
How much research material is actually included?
6. Shipping
What are the supplier's current dispatch and delivery terms?
7. Storage
Does the product documentation describe appropriate storage conditions?
8. Final cost
What does the order cost after quantity discounts, shipping, and applicable promotions?
The broader supplier comparison guide can help put those criteria into context:
American Peptides vs Peptide Sciences comparison
The role of HPLC and mass spectrometry
HPLC and mass spectrometry answer different analytical questions.
HPLC is useful for assessing chromatographic purity and separating the target peptide from related components.
Mass spectrometry is used to support identity by measuring molecular mass.
American Peptides states that its research-grade peptides are characterized using both methods and linked to lot-specific COAs.
That combination is more informative than a purity percentage by itself because a single number does not explain how the number was established.
A practical catalog-selection workflow
For a researcher comparing the American Peptides GLP-1 catalog, a simple workflow looks like this:
Step 1: Define the molecular question
Determine whether the project is centered on GLP-1R, GIPR + GLP-1R, GIPR + GLP-1R + GCGR, amylin-related signaling, or a combined pathway.
Step 2: Select the relevant catalog material
Match that question to Semaglutide, Tirzepatide, Retatrutide, Cagrilintide, or the combination product.
Step 3: Check the exact product page
Review the available quantity, price, product format, and current availability.
Step 4: Check lot documentation
Locate the relevant COA and verify that it corresponds to the material you intend to purchase.
Step 5: Compare total cost
Include volume pricing, shipping, and any applicable LOOT10 savings.
Step 6: Preserve the documentation
Retain the product identifier, lot number, COA, and purchasing information with the research record according to laboratory procedures.
How the American Peptides GLP-1 catalog compares conceptually with other suppliers
Researchers often find another supplier by searching phrases such as:
- GLP-1 research peptide supplier
- Semaglutide research peptide supplier
- Tirzepatide research peptide supplier
- Retatrutide research peptide supplier
- Cagrilintide research peptide supplier
- research peptide COA
- third-party tested GLP-1 research peptides
The most useful comparison isn't simply who lists the lowest number.
A serious supplier comparison should examine:
| Criterion | Why it matters |
|---|---|
| Catalog coverage | Determines whether one supplier can support multiple projects |
| Receptor/product information | Helps match material to the research question |
| COAs | Enables lot-level documentation |
| HPLC/MS | Provides analytical identity and purity evidence |
| Third-party testing | Adds independent verification |
| Quantity options | Changes effective cost |
| Volume pricing | Matters for larger legitimate orders |
| Shipping | Affects project timelines |
| Storage information | Supports appropriate laboratory handling |
| RUO labeling | Clarifies the product's intended research context |
This is also why "best" is a weak keyword for supplier selection. The best fit depends on the laboratory's criteria.
Related resources
For a broader metabolic catalog overview:
Best American Peptides for Metabolic Research: A 2026 Catalog Guide
For supplier comparison:
American Peptides vs Peptide Sciences Alternatives
For detailed price information:
American Peptides Price Guide 2026
For additional research references:
For receptor-level comparison:
Semaglutide vs Tirzepatide vs Retatrutide: 2026 Receptor Differences
Frequently Asked Questions
What GLP-1 research peptides does American Peptides sell?
The current GLP-1 & Metabolic collection contains Semaglutide, Tirzepatide, Retatrutide, Cagrilintide, and Retatrutide + Cagrilintide.
What is the cheapest GLP-1 research peptide at American Peptides?
Semaglutide is currently listed from $60, making it the lowest-priced product in the present GLP-1 & Metabolic collection.
How much is Tirzepatide at American Peptides?
The current listed starting price for Tirzepatide is $100.
How much is Retatrutide at American Peptides?
Retatrutide is currently listed from $105.
What is the difference between Semaglutide and Tirzepatide for research?
Semaglutide is classified as a GLP-1 receptor mono-agonist, while Tirzepatide is a GIP/GLP-1 dual agonist.
What is the difference between Tirzepatide and Retatrutide for research?
Tirzepatide is classified as a GIP/GLP-1 dual agonist, while Retatrutide extends the target profile to GIP, GLP-1, and glucagon receptors.
Is Cagrilintide a GLP-1 receptor agonist?
No. Cagrilintide represents an amylin-related metabolic research pathway, making it mechanistically distinct from the GLP-1/GIP/glucagon agonist sequence.
Does American Peptides provide COAs for GLP-1 research peptides?
American Peptides states that its research catalog uses lot-matched COAs and that batches undergo independent analytical testing.
What discount code does American Peptides have in 2026?
The current promotion supplied for this article is LOOT10, advertised as providing up to 30% off eligible purchases.
Does LOOT10 always give 30% off?
No guarantee should be assumed. The promotion is advertised as up to 30% off, so the applicable savings should be confirmed at checkout.
Are American Peptides GLP-1 products for human use?
No. The current American Peptides catalog states that these products are for laboratory and research use only and not for human or veterinary use.
Final takeaway
The American Peptides GLP-1 catalog is easiest to understand as a set of different research models rather than a list of competing consumer products.
Semaglutide provides a GLP-1 receptor-focused model.
Tirzepatide adds GIP receptor activity to create a dual-agonist model.
Retatrutide adds glucagon receptor activity and extends the comparison to a triple-agonist model.
Cagrilintide shifts the research question toward the amylin pathway.
Retatrutide + Cagrilintide provides a combined metabolic research material.
For procurement, the strongest comparison is not "which product sounds best?" It is:
Does this material match the research question, and does the supplier provide the documentation, quantity, analytical information, and final price required by the project?
American Peptides currently offers the five-product metabolic collection alongside its broader research catalog, and the current LOOT10 offer is advertised as providing up to 30% off eligible purchases.
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