SLU-PP-332

Made in a lab at Saint Louis University, SLU-PP-332 is a compact molecule built from ordinary chemistry rather than a peptide, designed to switch on a group of cell receptors called estrogen-related receptors. The nickname circulating for it, an exercise mimetic, reflects how switching on these receptors seems to trigger some of the same metabolic routes the body uses during actual physical activity, without the animal moving a muscle. So far it has only been tested in mice.

What it is

SLU-PP-332 targets a family of three receptors called ERR-alpha, ERR-beta, and ERR-gamma, with its strongest effect on ERR-alpha. These receptors sit inside cells and control which genes get switched on for building and running mitochondria, the small structures inside cells that produce usable energy.

SLU-PP-332 has no peptide sequence at all: it is built from ordinary small-molecule chemistry rather than amino acids linked into a chain, so it behaves differently in the body than the peptides described elsewhere in this reference. Researchers report it increases mitochondrial density in treated tissue and shifts cells toward burning fat for fuel.

How it is studied

All of the evidence for SLU-PP-332 comes from mouse studies using injections given into the abdominal cavity, tracking body weight, blood sugar control, exercise capacity on a treadmill, and, in a separate study, kidney tissue in older mice. No human trial has been conducted.

What studies report

In mouse models of obesity, SLU-PP-332 mimicked several exercise-linked benefits, including more energy burned at rest and more fat used for fuel, along with a drop in body fat and better insulin sensitivity, a measure of how well the body manages blood sugar. [1]
In 21-month-old mice, an aged group meant to model age-related kidney decline, 8 weeks of treatment was linked to less protein leaking into the urine, protection of specialized kidney filtering cells, and restored structure of mitochondria in kidney tissue. [2]
In mice given the compound, exercise endurance on a treadmill increased, along with a shift toward a type of muscle fiber (type IIa) built for sustained effort rather than short bursts of power, and the compound triggered the same genetic activity pattern the body normally shows right after a bout of aerobic exercise. [3]

What is not known

SLU-PP-332 has never been given to a person in a published study, so there is no human safety data, no established human amount, and no way yet to know whether the metabolic and exercise-related effects seen in mice would appear the same way in people.

Reported adverse findings

The mouse studies reviewed here focused on metabolic, kidney, and exercise-capacity outcomes rather than a full toxicity screen, and none report a formal adverse-event profile; human safety has not been studied at all. [1][2][3]

Regulatory status

No regulatory agency, including the FDA, has approved SLU-PP-332, and it has not entered human clinical trials. It remains a laboratory research compound, with researchers reportedly working toward an oral form and eventual human studies.