Is it really exercise in a pill?

In mice it reproduced part of the metabolic programme endurance training switches on. It did not reproduce the cardiovascular, skeletal, neurological or psychological effects of exercising, and no human has taken it. The phrase came from a press release.

No. Estrogen-related receptors do not bind oestrogen. They are orphan nuclear receptors named for a structural resemblance. It is a genuinely misleading name and it causes this question constantly.

Weight lossMuscle & performance

SLU-PP-332

Exercise in a pill · ERR agonist

PreclinicalReviewed 18 Aug 2026

SLU-PP-332 is a small molecule that activates the estrogen-related receptors, a family of transcription factors involved in mitochondrial biogenesis and oxidative metabolism. In mice it increased endurance capacity and reduced fat mass without a change in food intake. A striking result, and one widely reported as "exercise in a pill".

That phrase came from press coverage of a 2023 conference presentation and subsequent papers. The science is genuine and early-stage academic pharmacology. The compound is not in human trials.

It is being sold to people about eighteen months after the first press cycle, which is roughly the current lag between a promising mouse result and a research-chemical listing. Nothing about that lag involves a toxicology study.

There is a specific reason to be cautious beyond the general absence of data. The ERR pathway sits at the centre of cellular energy metabolism, and it is also implicated in cancer biology. ERR-alpha activity is associated with poorer outcomes in several tumour types. Chronically activating it in a whole human is a question nobody has approached.

How it works

It is a pan-agonist of the estrogen-related receptors ERR-alpha, beta and gamma. Despite the name these are orphan nuclear receptors and not oestrogen receptors. They do not bind oestrogen. The naming is a historical accident that causes constant confusion.

ERR activation increases the transcription of genes for mitochondrial biogenesis, fatty acid oxidation and oxidative phosphorylation, much the same programme endurance training switches on.

In mice this produced increased running capacity and reduced fat mass without reduced food intake. That is what generated the interest.

The same pathway is active in tumour biology. Elevated ERR-alpha activity is associated with worse prognosis in several cancers, and that is the concern chronic pharmacological activation raises.

Quick reference

Commonly described dose: 500 mcg–2 mg
How often: Daily
Route: Oral or Subcutaneous
Where: Abdomen
Timing: No basis for a timing recommendation.
Storage once mixed: Refrigerated, 30 days

These describe what sources report, not what you should do. Full detail and provenance in the dosing section below.

Price index

Per-milligram pricing across vendors arrives with the directory. We are recording prices now so the history exists when the page ships.

Vocabulary on this page

Bioavailability: How much of an administered dose actually reaches the bloodstream. Injection is close to complete; swallowing a peptide is usually close to nothing.
Peptide: A short chain of amino acids: the same building blocks as a protein, in a chain short enough to behave differently.

The whole glossary →

Regulatory status — United States

Not approved anywhere and not in human trials. An academic research compound sold as a research chemical, typically as a powder with no pharmaceutical manufacturing behind it.

Last reviewed 18 Aug 2026. Regulatory positions in this category change frequently; we date this line so you can see how current it is.

What it is studied for

Each entry states the evidence behind it. We do not rank indications by effectiveness — for most compounds here, that would be a claim nobody can support.

Endurance and fat loss

Published review

What the mouse work showed.

EvidenceIn mice, increased running capacity and reduced fat mass without reduced food intake. No human has taken it in any trial.

Identity and clearance

Molecule

Class: Small-molecule nuclear receptor agonist, not a peptide
Molecular weight: 393.4 Da

Dose protocols reported in sources

Displayed for reference only. Every row says where it came from, and a trial protocol and a community convention are not the same kind of information. None of this is fed into the calculator, and none of it is a recommendation.

Dose protocols reported in sources, with the source of each.
Goal	Dose	Frequency	Route	Units	Source	Start this protocol
Commonly described community protocol	500 mcg – 2 mg	Daily	OralScaled from mouse doses by allometric guesswork. Note that the mouse studies dosed it by injection because oral bioavailability was poor. The route people are using is the one the research avoided.	—	Community practice	Start this

Start this copies a row into a protocol of your own, which you can then edit. Where a source gave a dose range or an ambiguous frequency, those fields arrive empty — we will not pick a number on your behalf.

CheckRows marked community practice describe what people commonly do, drawn from public discussion. They are not derived from any trial and are not evidence that a dose is safe or effective.

Safety

Reported effects

EverythingCommunity practice
Unknown
No human has taken this in any study. No adverse effect is recorded because nobody has looked.
Consequences of chronic ERR activationPublished review
Unknown, and the specific concern
The pathway is central to cellular energy metabolism and implicated in tumour biology. Long-term activation in a human is entirely uncharacterised.
Cardiac effectsPublished review
Unknown
ERR receptors are highly expressed in heart muscle, which is metabolically among the most demanding tissue in the body. Nothing has assessed what sustained activation does there.

When to stop

Palpitations, chest pain or breathlessness.
Unexplained fatigue, weight loss, or night sweats.
Any new lump or persistent unexplained symptom.
Any allergic response: rash, hives, facial swelling or difficulty breathing. Seek urgent care.

Interactions and situations that need care

Any history of cancerAvoid
ERR-alpha activity is associated with poorer outcomes across several tumour types. Deliberately activating that pathway with an uncharacterised compound is the clearest specific risk this molecule carries.
Any cardiac conditionAvoid
ERR receptors are highly expressed in the heart. Nothing establishes what sustained pharmacological activation does to cardiac metabolism.
Pregnancy and breastfeedingAvoid
No reproductive or developmental data of any kind, for a compound that reprograms cellular metabolism.
Using it at all, at this stageUse caution
This is an academic compound about eighteen months past its first press cycle, with no human trial, no toxicology in humans, and no pharmaceutical manufacturing behind what is being sold. The mouse result is genuinely interesting. That is a reason to follow the research, not to be the first person taking it.

What to expect

HonestlyThere is no human efficacy data for this compound, so there is no evidence-based timeline to give. Any site publishing a week-by-week schedule of expected effects has invented it.

No human has taken this in a study of any kind.
'Exercise in a pill' came from press coverage, not from a finding in people.
The ERR pathway is implicated in tumour biology, which makes chronic activation a specific concern, not a generic unknown.
The mouse work dosed it by injection because oral absorption was poor. Powders sold for oral use skip that.
It is not a peptide, and it is not oestrogenic despite the receptor family's name.

Storage and handling

Freeze-dried powder: Refrigerated or frozen, protected from light.
After mixing: A small molecule, not a peptide. Solvent choice varies, and vendors rarely say what theirs is.
Long-term, frozen: Stable frozen.

Printable one-pager How to reconstitute a vial, step by step

Checking your vial

Research chemicals carry no manufacturing standard, so what the vial looks like is often the only quality signal available before you use it. More on assessing quality and COAs.

Appearance tells you nothing here
A research-chemical powder cannot be assessed by eye, and there is no reference product to compare it against.
No certificate of analysis
For a compound this new, third-party identity and purity testing is the only evidence you have that the powder is what the label says.

Questions

Is it really exercise in a pill?: In mice it reproduced part of the metabolic programme endurance training switches on. It did not reproduce the cardiovascular, skeletal, neurological or psychological effects of exercising, and no human has taken it. The phrase came from a press release.
Is it oestrogenic?: No. Estrogen-related receptors do not bind oestrogen. They are orphan nuclear receptors named for a structural resemblance. It is a genuinely misleading name and it causes this question constantly.

References

SLU-PP-332, a pan-ERR agonist, increases endurance and reduces adiposity in mice
Journal of Pharmacology and Experimental Therapeutics, 2023 · Animal study
Mice
Increased running endurance and reduced fat mass without reduced food intake, attributed to increased mitochondrial biogenesis and fatty acid oxidation. No human studies have been conducted. ERR-alpha activity is separately implicated in tumour biology, which the work does not address.
10.1124/jpet.123.001733
Clinic and community practice, unverified
Med-spa marketing, compounding pharmacy menus and forums, 2026 · Anecdote
Self-selected, unverified
Formulations and schedules described outside any trial. Compounded blends vary between pharmacies, so two products under the same name are not necessarily the same thing.

Related compounds

Semaglutide

A long-acting GLP-1 receptor agonist approved for type 2 diabetes and for weight management, dosed once weekly.

Tirzepatide

A once-weekly dual agonist that activates both the GIP and GLP-1 receptors, approved for type 2 diabetes and for weight management.

Retatrutide

An investigational once-weekly triple agonist acting on the GLP-1, GIP and glucagon receptors. Not approved anywhere.

Liraglutide

The first GLP-1 analogue approved for weight loss. A daily injection, superseded by weekly semaglutide but still the best-documented compound in the class.

Keep this page honest

If something here is wrong, out of date, or missing a source, tell us and we will fix it and say that we did.

Suggest a correction

This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice. No clinician reviews these pages.

Page last updated 18 Aug 2026