The best peptide stack for fat loss.

The honest version first

Let's be straight with you up front. When people talk about a "fat-loss peptide stack," almost all of the real work is done by one component: a GLP-1 receptor agonist. The other peptides in this guide play supporting roles. They are not the engine. If you remove the GLP-1, you do not have a fat-loss stack anymore, you have a handful of compounds with modest, mostly unproven effects on body composition.

We are a price-comparison and lab-data site. We do not sell peptides, and we are not going to promise you a number on a scale. There is no weight-loss guarantee here, and nothing in this article is medical advice. Most of what we list is sold for research use only, and prescription GLP-1 medications (the FDA-approved branded versions) exist through a licensed clinician. With that said, here is how a fat-loss stack is usually put together, what each piece adds, and what each one costs at the best price we can find.

The engine: a GLP-1 (tirzepatide or retatrutide)

This is the part that actually moves the needle. GLP-1 receptor agonists work largely by reducing appetite and slowing how fast your stomach empties, which tends to lower how much you eat without you white-knuckling it. Tirzepatide is a dual GLP-1 and GIP agonist, and retatrutide is a triple agonist that adds glucagon activity. Both are research compounds in this context, and both have prescription counterparts that a clinician can prescribe.

On price, the two are not close. The best price we track for tirzepatide is $3.17/mg ($94.99 for 30mg from Onyx Biolabs), with top lab-verified purity around 99.22%. Retatrutide runs higher at $8.0/mg ($159.99 for 20mg from Onyx Biolabs), with top purity around 98.77%. Tirzepatide is the more affordable and more established of the two; retatrutide is newer and pricier. If you are weighing them against each other, read our full comparison below.

• Tirzepatide: best price $3.17/mg, top purity ~99.22%
• Retatrutide: best price $9.00/mg, top purity ~98.77%

Fat-metabolism support: AOD-9604

AOD-9604 is a fragment of human growth hormone studied for its effect on fat metabolism without the broader growth-hormone effects on blood sugar. The pitch is that it nudges the body toward using fat for fuel. The honest caveat is that the human evidence is thin and underwhelming, so treat this as a supporting role and not a reason to expect anything dramatic on its own.

If you do add it, the best price we track is $10.60/mg ($53 for 5mg from EZ Peptides), with top lab-verified purity around 99.67%. Dosing here is qualitative on purpose; figure out the protocol with a clinician rather than a forum.

• AOD-9604: best price $10.60/mg, top purity ~99.67%

The GH and visceral-fat angle: tesamorelin

Tesamorelin is a growth-hormone-releasing hormone analog that has been studied specifically for reducing visceral fat, the deep abdominal fat around your organs. Of the supporting compounds here, it has the most serious clinical history behind it. It is included in a fat-loss stack for that visceral-fat angle rather than for overall weight on the scale.

It is also one of the better-value items in this lineup. The best price we track is $4.20/mg ($42 for 10mg from Next Gen Peptides), with top lab-verified purity around 99.97%, the highest in this stack. As always, dosing and whether it fits your situation is a conversation for a clinician.

• Tesamorelin: best price $4.20/mg, top purity ~99.97%

Energy and adherence support: MOTS-c

MOTS-c is a mitochondrial-derived peptide studied for its role in energy metabolism and exercise capacity. In a fat-loss context, people add it less for direct fat-burning and more for the energy and adherence side: a GLP-1 cuts your appetite, but it can also leave you feeling flat, and staying active is a big part of keeping the process going. Think of MOTS-c as the compound that supports the work you are already putting in, not a shortcut around it.

The best price we track is $3.00/mg ($120 for 40mg from Onyx Biolabs), with top lab-verified purity around 99.76%. That makes it the cheapest per milligram in this stack.

• MOTS-c: best price $3.00/mg, top purity ~99.76%

What it costs and how to compare

Sticker prices lie, because vials come in different sizes. A $180 vial and a $42 vial tell you nothing until you divide by the milligrams inside. That is why we compare everything by price per milligram. Here is the whole stack, role by role, at the best price we track.

The per-mg view changes how the stack feels. The engine, tirzepatide, is also one of the cheapest pieces by milligram, while AOD-9604 is the priciest despite the smallest sticker. Prices and best-price vendors move, so check the live numbers before you buy anything.

Honest caveats

A few things worth being clear-eyed about before you talk yourself into anything.

• GI side effects are common with GLP-1s. Nausea, constipation, and general gut upset are the usual complaints, especially early on.
• Titration matters. GLP-1s are typically started low and increased slowly to manage side effects. Jumping to a high dose tends to backfire.
• This is research-use-only territory. Most of what is listed here is sold for research use, not for human consumption. Prescription GLP-1 versions exist through a licensed clinician, and that may be the safer and more appropriate path.
• The supporting compounds are supporting. AOD-9604, tesamorelin, and MOTS-c will not carry a fat-loss result on their own. The GLP-1 is the engine.
• Purity varies by vendor. Check the lab data before you trust a number on a label.

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