WADA's 2027 list names SLU-PP-332 from January 1. pepmg found no published study that gave the molecule to a person.

The molecule

A small molecule on a peptide shelf

PubChem records SLU-PP-332 as 4-hydroxy-N'-(naphthalen-2-ylmethylidene)benzohydrazide, CAS 303760-60-3, formula C18H14N2O2, molecular weight 290.3.[22] It is an acylhydrazone, a small synthetic molecule rather than a chain of amino acids; it appears in pepmg's index because the vendors pepmg tracks sell it next to their peptides.[25]

Researchers in St. Louis described it in 2023. They started from GSK4716, an agonist selective for the estrogen-related receptors ERRβ and ERRγ, and modified it for activity at ERRα, reporting that they "gained 50-fold ERRα potency."[8] The result is a pan agonist of ERRα, ERRβ and ERRγ with its highest potency at ERRα, which the authors presented as a chemical tool for switching on the gene programs that aerobic exercise switches on.[7] A 2026 structure-activity paper from the same circle calls it "a well-established exercise mimetic and widely used chemical probe for ERR activation."[18]

The people who made it have commercial interests in the class, and they say so: the 2023 paper's conflict statement declares three authors to be stockholders in Myonid Therapeutics, and the 2026 structure-activity paper declares two authors to be cofounders and stockholders of Pelagos Pharmaceuticals.[7][18]

The anti-doping change

What the 2027 Prohibited List actually says

WADA published the 2027 Prohibited List on September 21, 2026, and it comes into effect on January 1, 2027.[3] pepmg read the list text in the complete copy published by the Italian football federation from NADO Italia on October 7, 2026, because WADA's own document host returned a challenge page rather than the PDF to pepmg's requests.[1][2] In section S4.4.1, under metabolic modulators, one bullet reads in full: "SLU-PP-332, SLU-PP-915 and related substances."[2]

Two details in the same document matter more than the naming. The S4 class is headed "PROHIBITED AT ALL TIMES (IN- AND OUT-OF-COMPETITION)," so it is not limited to competition days, and the list states that "Prohibited substances in classes S4.1 and S4.2 are Specified Substances. Those in classes S4.3 and S4.4 are non-Specified Substances."[2]

This is a naming, not a new prohibition. UK Anti-Doping says the four S4 additions for 2027, imlunestrant, seladelpar, SLU-PP-332 and SLU-PP-915, "are not new substances being added to the 2027 List for the first time but are additional examples of substances that are already prohibited."[3] USADA lists the pair as "metabolic modulators acting on oxidative metabolism."[4] In a third-party copy of the 2026 list, section S4.4.1 names AMPK activators such as BAM15 , AICAR and MOTS-c , PPARδ agonists and Rev-erbα agonists, but neither SLU compound.[5]

What the listing is not: it binds athletes under the World Anti-Doping Code, and it is not a drug approval decision, a safety finding or a statement about anyone outside sport. The 2027 list's S0 class, non-approved substances, names BPC-157 among its examples.[2]

The human record

Ten papers, none of them an administration study

A PubMed search for SLU-PP-332 on November 5, 2026 returned ten records.[6] None of them gave the compound to a person. Four are animal studies: the 2023 paper that introduced it, a 2024 study in diet-induced obese and ob/ob mice reporting increased energy expenditure, increased fatty acid oxidation and decreased fat mass, a 2024 Circulation study in a mouse pressure-overload heart failure model, and a 2023 study treating 21-month-old mice for 8 weeks to probe the aging kidney.[7][9][10][11]

The record that comes closest to people is a 2025 pilot study in Frontiers in Physiology. It enrolled 20 women having hip replacement surgery, split 10 active and 10 inactive by self-reported activity, took muscle biopsies during surgery, and then treated myoblasts cultured from the inactive women's tissue with SLU-PP-332.[12] That is human cells in a dish, not a dose given to a volunteer.

Two 2026 papers are anti-doping chemistry, written before the listing: the Cologne authors note that non-approved substances with performance-enhancement potential "can be subject of the World Anti-Doping Agency (WADA) Prohibited List" and that "proactive analytical consideration in preventive anti-doping research is critical."[16] Both incubated it with human liver preparations in vitro to find metabolites a laboratory could screen for. The Cologne group identified nine metabolites for SLU-PP-332, six Phase I and three Phase II, and wrote that "further research is needed to address the metabolic behavior in vivo and to ensure effective detection of both substances in human urine samples."[15][16] A second group reported 22 metabolites from pooled human liver S9 fractions.[17]

A 2026 systematic review in Revista Médica de Chile, covering the literature from 2020 to 2024, reviewed animal and cell models and concluded that "clinical trials are needed to confirm their efficacy and safety in humans."[14] ClinicalTrials.gov returned no study for SLU-PP-332 and none for SLU-PP-915 on November 5, 2026.[19]

The animal evidence

Injected mice ran longer, and the effect needed ERRα

In the 2023 paper, male C57BL/6J mice received 50 mg/kg by intraperitoneal injection. A single dose an hour before a treadmill test increased running distance and running time against vehicle, with six mice per group.[8] After 14 days of twice-daily dosing, mice with ERRα deleted in muscle treated with SLU-PP-332 showed "exercise endurance equivalent to vehicle-treated" knockouts, while the floxed controls improved, which is the paper's evidence that the effect runs through ERRα.[8]

On safety, the authors report "no overt toxicity in mice administered SLU-PP-332 (50 mg/kg b.i.d., i.p.) for 10 days," with normal blood counts and electrolytes and no significant change in serum creatine kinase.[8] That is an observation in mice over ten days. It is not a human safety record, and no published work reports what repeated dosing does in a person.

Route

The developers say it is not orally available

In January 2026 the same laboratory introduced SLU-PP-915, a chemically distinct ERR pan-agonist, and described the reason for building it in one line: "We previously developed an ERR pan-agonist, SLU-PP-332 (332), which improves aerobic performance in mice but lacks oral bioavailability."[13] They report that 915 keeps comparable activity when given by mouth, adjusted for systemic exposure, while 332 was the injected tool compound.[13] Every mouse experiment pepmg read dosed 332 intraperitoneally.[8]

In pepmg's index generated November 5, 2026, 31 of 86 SLU-PP-332 listings are named as capsules, tablets or an oral form, and five more as an "Encapsulated Research Formulation": 36 of 86 meant to be swallowed.[25] pepmg has no way to know what any of those products contain, and the published record does not support an oral route for this molecule.

Status

No approval, no compounding nomination

A search of Drugs@FDA and the National Drug Code directory through openFDA on November 5, 2026 returned no product with SLU-PP-332 as an active ingredient.[20] The molecule appears in none of the three categories of FDA's 503A bulk drug substance nominations list, updated May 14, 2026, which pepmg read page by page.[21] pepmg did not check the 503B list.

HHS's enforcement-discretion policy announced in the Federal Register on October 30, 2026 is about peptide bulk drug substances compounded under section 503A.[23] The six substances it covers are BPC-157, Epitalon, KPV, MOTS-c, Semax and TB-500.[24] SLU-PP-332 is not a peptide and is not among them.

The market

Thirty-nine vendors, eighty-six listings, no label

pepmg's index generated November 5, 2026 shows SLU-PP-332 at 39 vendors in 86 listings, from 0.25 mg to 150 mg, in vials, dry-fill powder, capsules and tablets, with one listing named as raw powder, one as a 1% topical and three flagged by the index as capsule blends with BAM15 .[25] Those listings are a market snapshot, not evidence about the molecule. Nothing in the published record describes what one of these products should contain, what it does in a person, or at what dose, and from January 1 an athlete under the Code who takes any of them is taking a substance named on the Prohibited List.[2]

Questions people are asking