SLU-PP-332: What the Evidence Actually Shows

SLU-PP-332 is a synthetic small molecule that activates a family of nuclear receptors called estrogen-related receptors (ERRα, ERRβ, and ERRγ) — not a peptide, not a GLP-1 drug, and not related in structure to anything else on this site's board pages. It's earned a "exercise in a pill" nickname in longevity and biohacking coverage, and the mechanistic story behind that framing is real and published — but so is a fact that framing tends to leave out: SLU-PP-332 has never been tested in a single human being. Every published result is a mouse or cell-line study. This article states exactly what's been shown, and exactly which species it's been shown in, throughout.

Why this compound exists — a real chemistry problem it was built to solve

ERRs are orphan nuclear receptors known to play a real role in skeletal-muscle exercise capacity, but researchers had a genuine, longstanding chemistry problem: "there have been significant difficulties in designing compounds with ERRα agonist activity," and existing synthetic ERR agonists weren't usable in living animals¹. SLU-PP-332 was identified specifically to solve that gap — a synthetic pan-ERR agonist with the highest potency for ERRα, and, unlike earlier attempts, "sufficient pharmacokinetic properties to be used as an in vivo chemical tool¹." That's the actual scientific news value here: not a marketed supplement, but a research tool finally capable of testing what activating ERRα actually does in a living system.

What it did in mice — three independent labs, three different disease models

In the original 2023 identification paper, SLU-PP-332 increased mitochondrial function and cellular respiration in a skeletal-muscle cell line, and when given to mice, increased type IIa oxidative skeletal-muscle fibers and enhanced exercise endurance, while inducing an ERRα-specific acute aerobic-exercise genetic program¹. That's the finding behind the "exercise mimetic" framing — a real, published result, in mice, not in humans.

Two independent follow-up studies, from different research groups, extended the finding to different organ systems. A 2024 Circulation paper tested SLU-PP-332 (and a related compound, SLU-PP-915) in a pressure-overload-induced heart-failure mouse model, and found it ameliorated heart failure by enhancing cardiac fatty-acid metabolism and mitochondrial function². A separate 2023 paper in the American Journal of Pathology tested it in an aging-kidney mouse model, and found it reversed mitochondrial dysfunction and inflammation³. Three different labs, three different disease models — muscle/exercise, cardiac, and renal — converging on the same compound and a shared underlying theme: restoring mitochondrial function via ERR activation. That convergence is a genuinely stronger preclinical signal than a single lab's result would be, and it's reported here as exactly that: convergent animal evidence, not human evidence.

What has NOT been shown: anything in a human

A live PubMed search for "SLU-PP-332" returns exactly 10 total results, and every one is a mouse or cell-line study — zero human trials, zero case reports, zero human pharmacokinetic data of any kind. A live openFDA search finds no Drugs@FDA record, no DailyMed label, and — tellingly — zero FAERS adverse-event reports, because there is no recorded human exposure to report on at all. Every other compound covered in this site's wave-10 content batch (tesamorelin, ipamorelin, CJC-1295, MK-677) has at least a handful of FAERS reports reflecting real human use, however grey-market; SLU-PP-332 has none. It also doesn't appear anywhere on FDA's current 503A compounding-bulks list, consistent with it never having been sold as a compounded product at all.

What this means if you're considering it

SLU-PP-332 is a real, actively-researched compound with a genuinely interesting and convergent preclinical story across three independent mouse studies spanning muscle, heart, and kidney tissue. It is also, as of this review, a pure research tool with no human trial of any kind behind it — no established human dose, no confirmed human safety profile, and no FDA involvement at any stage. That's a meaningfully earlier-stage evidence position than most of the non-approved compounds this site covers, and it's worth understanding the difference between "published mouse data exists" and "this has been tested in people" before treating the two as equivalent. No reviewed or non-boarded provider on this site's roster sells it, and no reconstitution calculator exists for it — there's no established human dose or administration route for a calculator to model.