Peptides · Metabolic

SLU-PP-332

Also known as: SLU-PP-332, exercise mimetic, ERR agonist

A small-molecule 'exercise mimetic' that activates ERR receptors. Mouse data only, no human trials, and not a peptide.

metabolicfat lossendurancemitochondriaexercise mimetic
Half-life
Not established in humans. Reported to be short in mice, which is not a safe basis for human dosing.
Route
Unknown for humans. Mice were dosed by injection; vendors sell it as a powder for oral or injected use.
Shelf life (powder)
Stable as a dry powder if stored cold and dark, typically years; check supplier data
Shelf life (mixed)
Unknown; depends on solvent. Do not assume it is the same as a peptide.
Storage
Dry powder: fridge or freezer, dark. Solutions: fridge, short term.

Read this first

This is plain-language harm-reduction information, not medical advice. Peptides discussed here are research compounds; most are not approved for human use. People will use them either way — we would rather they have the facts.

What it is

SLU-PP-332 is not a peptide. It is a small synthetic molecule (a chemical compound) that activates a family of receptors called estrogen-related receptors (ERRs), which help control how muscle cells burn energy. It has been called an 'exercise mimetic' because in mice it triggered some of the same changes as exercise.

Everything known about it comes from lab and mouse studies. There are no published human trials, no known human dose, no safety data in people, and no regulator has approved it for anything. Anyone telling you what dose works in humans is guessing.

History

SLU-PP-332 was developed by academic researchers and described in a scientific paper in 2023. As I understand it, 'SLU' refers to Saint Louis University, where the work was partly based, though that detail is not something to rely on. It appeared in the research-chemical market within a year or two of the paper, well before any human work.

How it works

ERRs (especially ERR-alpha) switch on genes involved in mitochondria and fat-burning in muscle, and are naturally turned up by exercise. In mice, SLU-PP-332 increased the use of fat for fuel, improved endurance on a treadmill and reduced fat gain on a high-fat diet. Whether it does anything similar in people, at what dose, and with what side effects is unknown.

Dosage

  • There is no human dose. Do not extrapolate from mouse doses: mouse studies dose per kilogram of a very different animal, and the human numbers circulating online are guesses.
  • No credible human dosing protocol exists, so we do not give one.

How it is taken

  • No established route in humans. Mice in the original studies were injected.
  • Unlike most peptides on this site, it is a small molecule that is poorly water-soluble and is generally dissolved in an organic solvent (such as DMSO) or a specialised carrier for research. That makes self-injecting riskier, not simpler.

How to reconstitute

  • A 5 mg vial does not simply dissolve in bacteriostatic water the way a peptide does. We do not give a mixing recipe, because there is no tested human formulation.
  • For arithmetic only: 5 mg dissolved in 1 ml of liquid would be 5 mg/ml, so 10 units on a 1 ml / 100-unit syringe (0.1 ml) would be 0.5 mg. This is not a suggestion to inject it or a dose; it is just how concentration maths works for any solution.
  • Check your supplier's solubility information before doing anything.

How it should arrive

Sealed vial with a dry powder, usually white or off-white. Because it is a small molecule rather than a peptide, it may not be a fluffy lyophilised cake.

How it should look once reconstituted

Depends on the solvent. Any solution should be clear, with no crystals, cloudiness or particles. If it falls out of solution when cooled, do not inject it.

What to expect, and when

  • Unknown in humans.
  • In mice, effects on endurance and fat gain appeared over a couple of weeks of daily dosing.
  • Anyone reporting human results is giving anecdote from a research chemical of uncertain quality.

Side effects

  • Not established in humans.
  • Effects reported anecdotally in the community, such as fatigue, nausea or headache, cannot be separated from placebo or poor product quality.
  • If injected as a solution in organic solvent, irritation and tissue damage at the site are plausible.

Risks

  • No human safety data at all. Mouse studies are short and cannot show long-term risks. Effects on the heart, liver, metabolism and cancer risk are unknown.
  • ERRs are involved in many tissues. A drug that switches on a master metabolic regulator could have effects well beyond muscle. Some ERR biology has been linked to cancer, though that is not evidence this compound causes harm.
  • Quality: research-chemical powders vary in identity and purity, and the product is not made to injectable standards.
  • Injecting a poorly soluble compound in a solvent carries added risks of infection, irritation and tissue damage.
  • Not approved by any regulator. It is likely prohibited under WADA's general rule on unapproved substances (S0); check the current list if you compete.
  • Not for pregnancy or breastfeeding, and not for people with heart, liver or kidney disease.

Potential gains

  • In mice: improved endurance, increased fat use for fuel and less weight gain on a high-fat diet.
  • In humans: nothing demonstrated.
  • It is not a replacement for exercise: the cardiovascular, bone and mental-health benefits of exercise are not explained by one pathway.

Other useful information

Honest summary: interesting science, not yet a usable human product. If you want to lose fat or improve fitness, exercise and diet have actual human evidence, and licensed weight-loss medicines exist for those who qualify. If you decide to take SLU-PP-332 anyway, you are effectively the first human subject, which is a real position to be in. Keep any exposure as low as practical, stop at any unexpected effect, and tell a clinician.

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