Peptide stacks: what each common component has shown alone

The short answer: no published trial has tested a multi-peptide stack for muscle growth, fat loss, or body composition. Every claim about a "peptide stack" is built from studies of each ingredient taken alone, and for most of those ingredients the studies are in animals. [9] This page ranks nine common stack components by what each has shown on its own, with its legal and anti-doping status.

This page does not give protocols, doses, cycles, or instructions for combining anything. For the unapproved compounds on this list, no human dose has been established for body composition, and combining them adds unknowns that no study has measured.

What is a peptide stack?

A stack is two or more compounds used at the same time toward one goal. The common pattern pairs a growth hormone releaser with a secretagogue (the CJC-1295 and ipamorelin pairing, or tesamorelin and ipamorelin), adds a healing peptide for recovery (the Wolverine stack of BPC-157 and TB-500), or adds a metabolic compound for fat loss.

The logic behind stacking is usually mechanism: two compounds acting on different receptors should, in theory, add up. In practice that theory has not been tested. A combination can add benefits, cancel them, or add side effects, and the only way to know is a trial of the combination.

Has any trial tested a peptide stack?

Not for body composition. We found no published randomized trial of any multi-peptide stack for muscle growth, fat loss, or recovery. The closest human data are single-compound studies, summarized below. For example, CJC-1295 raised growth hormone and IGF-1 in healthy adults, but that study measured hormone levels, not muscle or fat. [6]

How we ranked stack components

We ordered the nine components by three criteria:

1. Human evidence for a body composition outcome (fat, lean mass, or weight) from a randomized trial.
2. Human evidence for anything, such as hormone levels or an unrelated condition.
3. Lawful access today, from each compound's record, verified in September 2026.

Grades and statuses come from our dataset. The ranking says nothing about whether any combination works.

1. Tesamorelin

• GradeEvidence: Human RCT
• StatusRegulatory: FDA approved
• WADAWADA: Prohibited

Tesamorelin is approved as Egrifta to reduce excess abdominal fat in adults with HIV-associated lipodystrophy. [2] In a pooled analysis of two phase 3 trials with 806 patients, visceral fat changed by minus 24 square centimeters versus plus 2 on placebo at 26 weeks, with no change in fat under the skin of the abdomen. [1] That is real body composition data, but in a specific population, and the fat returned after stopping. [1]

It is the only growth hormone releasing compound on this list with a lawful prescription path. See tesamorelin cost, tesamorelin vs CJC-1295, and our post on whether tesamorelin builds muscle.

2. Semaglutide and tirzepatide

• GradeEvidence: Human RCT
• StatusRegulatory: FDA approved
• WADAWADA: Not prohibited

The GLP-1 drugs have the largest fat loss trials of any peptide. In STEP 1, semaglutide produced a mean weight change of minus 14.9% at 68 weeks versus minus 2.4% on placebo. [3] In SURMOUNT-1, tirzepatide produced minus 15.0% to minus 20.9% across three doses at 72 weeks versus minus 3.1% on placebo. [4]

These trials measured weight loss as a whole, not muscle gain, and they did not test GLP-1 drugs combined with growth hormone releasers or healing peptides. Our peptides for weight loss roundup ranks the options, and the fat loss page covers standard care.

3. MK-677 (ibutamoren)

• GradeEvidence: Human RCT
• StatusRegulatory: In FDA Category 2, cannot be compounded
• WADAWADA: Prohibited

MK-677 is not a peptide; it is an oral small molecule that acts on the ghrelin receptor. It is on this list because it is one of the most common stack ingredients and because it has the best lean mass data among them. In a 2-year trial of 65 healthy adults aged 60 to 81, fat-free mass changed by plus 1.1 kg with MK-677 and minus 0.5 kg with placebo after one year, but strength and function did not change. [5] Fasting glucose rose and insulin sensitivity fell. [5]

FDA placed it on the Category 2 list of substances that raise significant safety risks, so no pharmacy can lawfully compound it. [14] See ipamorelin vs MK-677.

4. CJC-1295

• GradeEvidence: Human RCT (hormone levels only)
• StatusRegulatory: No lawful path
• WADAWADA: Prohibited

CJC-1295 is a long-acting growth hormone releasing hormone analog. In two randomized trials in healthy adults, single injections raised growth hormone 2 to 10 fold for 6 days or more and IGF-1 1.5 to 3 fold for 9 to 11 days. [6] No trial measured muscle, fat, strength, or recovery.

It was never approved, and its nomination for compounding was withdrawn, so it is not on the bulks list and has no lawful compounding path. [13] Track it on the CJC-1295 regulatory page, and see CJC-1295 cost for why advertised prices are not comparable.

5. Ipamorelin

• GradeEvidence: Animal only for body composition
• StatusRegulatory: No lawful path
• WADAWADA: Prohibited

Ipamorelin is a selective growth hormone secretagogue. Its one published randomized trial tested it after bowel surgery: median time to a tolerated meal was 25.3 hours versus 32.6 hours with placebo, a difference that was not statistically significant. [7] No trial has measured body composition.

Its nomination was withdrawn and it is not on the bulks list, so it has no lawful compounding path. [13] The most searched pairing is covered on CJC-1295 vs ipamorelin, and prices on ipamorelin cost.

6. BPC-157

• GradeEvidence: Animal only
• StatusRegulatory: Awaiting FDA final rule
• WADAWADA: Prohibited

BPC-157 is the usual recovery ingredient in a stack. In rats it sped healing of a cut Achilles tendon. [8] Human data are three small uncontrolled pilot reports with no control group; no randomized trial has reported. [17] There is no muscle growth or fat loss data in people. The advisory committee recommended it for the 503A bulks list in July 2026, but no final rule has been published. [15] The muscle recovery page covers what does have human evidence.

7. TB-500

• GradeEvidence: Animal only
• StatusRegulatory: Awaiting FDA final rule
• WADAWADA: Prohibited

TB-500 is sold as a synthetic version or fragment of thymosin beta-4, which sped skin wound closure in rats. [10] It has no human body composition or recovery trial. It shares BPC-157's regulatory position. [15] WADA names it in section S2. [16]

8. MOTS-c

• GradeEvidence: Animal only
• StatusRegulatory: Awaiting FDA final rule
• WADAWADA: Prohibited

MOTS-c is a peptide encoded in mitochondrial DNA. In mice on a high fat diet, daily MOTS-c prevented weight gain and insulin resistance. [11] No human treatment trial has been published. It was among the peptides recommended for the bulks list in July 2026, with no final rule yet. [15]

9. 5-amino-1MQ

• GradeEvidence: Animal only
• StatusRegulatory: No lawful path
• WADAWADA: Prohibited

5-amino-1MQ is another small molecule, not a peptide, sold alongside peptides for fat loss. In diet-induced obese mice it reduced body weight and white fat mass over 11 days. [12] No human study exists. It is not on the bulks list or in Category 2 and has no USP monograph, which leaves no lawful basis for compounding it. [13]

Is there a best peptide stack for muscle growth and fat loss?

No one can name one from evidence, because no trial has compared stacks. Taken one at a time, the evidence looks like this:

• Fat loss: the approved GLP-1 drugs have the strongest data, and tesamorelin reduces visceral fat in HIV lipodystrophy. [1] [3]
• Lean mass: MK-677 raised fat-free mass modestly in older adults without improving strength, and it carries glucose and safety concerns. [5]
• Growth hormone releasers: CJC-1295 raises hormone levels, which is not the same as building muscle. [6]

Our peptides for muscle growth roundup covers the muscle side in more detail.

Are peptide stacks legal?

A stack inherits the status of its strictest ingredient. From this list, only tesamorelin and the GLP-1 drugs have a lawful prescription path today. BPC-157, TB-500, and MOTS-c wait on an FDA final rule. [15] CJC-1295, ipamorelin, MK-677, and 5-amino-1MQ have no lawful path. [13] [14] That means the most common growth hormone pairings, which contain ipamorelin, have no lawful path either. State rules are on our state law pages.

For the lawful route for each ingredient, see how to get peptides prescribed; for what clinics mean when they sell a stack as peptide therapy, see our explainer.

Can athletes use peptide stacks?

Tested athletes should assume not. WADA section S2 covers growth hormone releasing factors and secretagogues, and section S0 covers substances with no approval for human use. [16] Eight of the nine components on this list are prohibited; only the GLP-1 drugs are not.

The takeaway

A peptide stack is a hypothesis, not a treatment. The components with human body composition data (tesamorelin, the GLP-1 drugs, and MK-677) were each tested alone, in specific populations, and none was tested in combination with the others. We will update this page if a trial of any combination is published.