Best Peptides for Endurance: Ranked Research Guide

What are the best peptides for endurance in current research?

The most-cited endurance research compounds are SLU-PP-332, MOTS-c, and SS-31, but only two are peptides and all three rest mainly on animal data.

"Best" here means most-studied for aerobic capacity, not most proven in people. Endurance biology comes down to how well muscle mitochondria produce energy and how the body shifts toward fat-burning, oxidative muscle fibers during sustained effort. The compounds below act on those pathways in preclinical models. What follows is what the published research reports, not a recommendation to use any of them.

One naming note: SLU-PP-332 is a small-molecule ERR agonist, not a peptide. It appears here because it shares the exercise-mimetic research space, and searchers group it with the peptides.

How do these endurance research compounds compare?

Here is a side-by-side of mechanism, test model, whether human data exists, and regulatory status.

Every row is preclinical for endurance specifically. No compound in this table has an approval for improving athletic performance in people.

What does the research say about SLU-PP-332?

In mice, SLU-PP-332 activated all three estrogen-related receptors (ERRs) and produced a large jump in running distance, but there are no human trials.

Billon et al., 2023 (ACS Chemical Biology) reported that treated mice ran roughly 45 percent farther than controls and showed a shift toward oxidative, fatigue-resistant type IIa muscle fibers, effects the authors described as mimicking parts of an endurance-trained state. ERRs help regulate genes tied to mitochondrial energy production, which is why an ERR agonist draws interest as an exercise mimetic.

The hedge matters: this is a small molecule, the data is in rodents, and no completed human study has tested it for safety or performance. Any translation to people is speculation at this stage.

What does the research say about MOTS-c?

MOTS-c is a peptide encoded in mitochondrial DNA that activates AMPK, a central energy-sensing pathway, and improved exercise capacity in mice.

Lee et al., 2015 (Cell Metabolism) identified MOTS-c and showed it regulates metabolic homeostasis through AMPK, with treated mice resistant to diet-induced metabolic problems. A later study, Reynolds et al., 2021 (Nature Communications), reported that MOTS-c improved physical performance in mice across young, middle-age, and old animals. AMPK activation is one of the same signals triggered by physical training, which is the mechanistic reason MOTS-c is grouped with exercise mimetics.

Human performance data for MOTS-c is not established. The molecule is real and the pathway is well described, but the endurance claims rest on animal work.

What does the research say about SS-31 (elamipretide)?

SS-31 targets mitochondrial membranes to support energy production, and improved exercise tolerance in aged mice, though human myopathy trials have shown mixed results.

SS-31, also called elamipretide, binds cardiolipin in the inner mitochondrial membrane and is studied for restoring mitochondrial function where it declines with age or disease. In aged mice, treatment reversed age-related redox stress and improved exercise tolerance, with more fatigue-resistant muscle and greater treadmill endurance (Campbell et al., 2019). Human trials in mitochondrial myopathy have reported mixed outcomes, so the picture in people is not settled.

For endurance specifically, the strongest signal is again in animals. SS-31 is investigational, not an approved performance agent.

Why is the human evidence for endurance peptides so thin?

Because nearly all endurance findings for these compounds come from rodents, and no completed human trial supports athletic-performance use.

Mouse running-wheel and treadmill studies are useful for mechanism, but they do not confirm the same effect, dose, or safety profile in trained humans. Across SLU-PP-332, MOTS-c, and SS-31, the endurance data is either rodent-only or, in SS-31's case, drawn from disease trials with mixed results rather than healthy performance studies. Treat every performance claim as a hypothesis, not a demonstrated outcome.

Is there research-reported dosing for endurance peptides?

There is no established human endurance dosing for any of these compounds, so no clinical range can be responsibly stated here.

SLU-PP-332 dosing exists only in mouse studies (Billon et al., 2023) and does not translate to a human protocol. MOTS-c and SS-31 human dosing, where studied, comes from metabolic or disease contexts, not endurance, and is not a guide for performance use. Because no human endurance trial has set a range, any personal decision about these compounds belongs with a qualified clinician, not a web page.