SLU-PP-332

Quickstart Highlights

SLU-PP-332 is a synthetic small molecule, not a peptide. It is a pan-agonist of the estrogen-related receptors, the orphan nuclear receptors that normally switch on after endurance exercise, and it is studied in mice as an exercise mimetic for endurance, fat loss and metabolic health. All published evidence comes from mouse intraperitoneal studies; no human trial exists, and the compound is prohibited in sport by WADA. This educational protocol presents once-daily subcutaneous injections for a 6–8 week cycle, stepping from 500 mcg in week 1 to a 1 mg working dose, using a 1.0 mL reconstitution of the 5 mg vial so each insulin-syringe unit delivers 50 mcg.

• Reconstitute: Add 1 mL bacteriostatic water → 5 mg/mL concentration.
• Dose range: 500 mcg–1.5 mg once daily, subcutaneously, in the morning 30–60 minutes before training (6–8 week cycle, then 4 weeks off).
• Easy measuring: At 5 mg/mL, 1 unit = 0.01 mL = 50 mcg on a U-100 insulin syringe.
• Storage: Lyophilized: freeze at −20 °C (−4 °F); after reconstitution, refrigerate at 2–8 °C (35.6–46.4 °F) and use within 28 days.
• Label: Not a peptide and not studied in humans. The compound is poorly water-soluble; some vendors use a DMSO co-solvent, so swirl thoroughly, allow extra time to dissolve and expect slight haze.

Protocol Overview

Concise summary of the once-daily injectable regimen.

• Goal: Activate ERR-driven mitochondrial and fatty-acid-oxidation gene programs to support endurance, fat loss and metabolic health, mimicking adaptations seen after aerobic training in mouse studies.
• Schedule: Daily subcutaneous injections in the morning for 6–8 weeks, followed by a 4-week break.
• Dose Range: 500 mcg (0.5 mg) once daily in week 1, then 1000 mcg (1 mg) once daily from week 2, with 1500 mcg (1.5 mg) daily as the upper reference.
• Reconstitution: 1 mL per 5 mg vial (5 mg/mL) for accurate unit measurements on standard insulin syringes.
• Storage: Lyophilized frozen at −20 °C (−4 °F); reconstituted refrigerated at 2–8 °C (35.6–46.4 °F); use within 28 days; avoid repeated freeze–thaw cycles.
• Evidence: Animal data only: mouse intraperitoneal studies from 2023–2024 (Billon et al., Xu et al.), with no registered human trial, no human pharmacokinetics and no human safety data. Confidence is low; the 500 mcg–1.5 mg daily convention is shared by four of seven sources but is community extrapolation, and the subcutaneous route itself has never been validated.

Dosing Protocol

Suggested daily approach based on research-community conventions; no human dose has been established.

• Week 1: 500 mcg (0.5 mg) once daily to assess tolerance, particularly sleep and resting heart rate; 10 units at the 5 mg/mL reconstitution.
• Week 2: 1000 mcg (1 mg) once daily; 20 units.
• Week 3 onward: 1000 mcg (1 mg) once daily as the standard working dose; 20 units. This is the modal maintenance figure across sources.
• Upper reference: 1500 mcg (1.5 mg) once daily; 30 units. This is the top of the modal range, not a target; two sources go higher, split across the day, and two others say no validated dose exists.
• Frequency: Once daily in the morning, 30–60 minutes before training. Because of the short half-life, the daily amount may be split into two injections (morning and pre-training).
• Timing: Morning, so that the dose precedes activity and sits well away from sleep; the rodent half-life of 1.5–4 hours is the stated reason some sources split the day.
• Cycle: 6–8 weeks on, then 4 weeks off. Sources range from 4 to 12 weeks on and 2 to 8 weeks off; one source states that any cycle length is invented, since no human data exist.
• Titration: One step, from 500 mcg to 1 mg after week 1; sources that escalate further do so only after two or more weeks of tolerance, and the 1.5 mg figure on this page is a reference ceiling rather than a scheduled step.

Storage Instructions

Proper storage preserves product quality and efficacy.

• Lyophilized (powder): Store at −20 °C (−4 °F) for long-term storage or refrigerated at 2–8 °C (35.6–46.4 °F), dry and protected from light and moisture.
• Reconstituted (solution): Refrigerate at 2–8 °C (35.6–46.4 °F), protected from light, and do not freeze. Use within 28 days; sources range from 14 to 30 days.
• Allow the vial to reach room temperature before opening to minimize condensation uptake.
• Solubility note: the compound is poorly water-soluble and some vendors supply it with a DMSO co-solvent. Swirl thoroughly after adding bacteriostatic water, allow several minutes, and expect slight haze; do not use a solution with visible particulates or one that will not clear with gentle warming to room temperature.

Important Notes

Practical considerations for consistency and safety.

• Use new sterile insulin syringes for each injection; dispose in a proper sharps container.
• Rotate injection sites systematically (abdomen, thighs, upper arms) to reduce local irritation and avoid lipohypertrophy.
• SLU-PP-332 is a small molecule (C18H14N2O2, 290.3 g/mol), not a peptide. Reconstitution math on this page uses the labeled 5 mg amount at 1.0 mL, but dissolution behavior differs from a peptide: two dosing sources note that water alone may not fully dissolve the powder without a DMSO co-solvent. Confirm with the supplier whether the vial is formulated for aqueous reconstitution.
• Not approved by Health Canada or the FDA; research use only. No IND exists, no human trial is registered, and the compound is not available through compounding pharmacies.
• Prohibited in sport: WADA lists SLU-PP-332 under S4.5 metabolic modulators, so it is banned in and out of competition for tested athletes.
• Evidence caveat: every human figure is a community extrapolation from 25–50 mg/kg intraperitoneal mouse doses given twice daily, amounts that would be grams per day in a human. The widely quoted 250 mcg/day figure has no peer-reviewed source, and the subcutaneous route has never been validated.
• Cardiac caution: estrogen-related receptors are active in the heart, cardiac hypertrophy has been reported in some higher-dose rodent protocols, and cardiac substrate switching is a documented concern. Elevated resting heart rate is one of the most commonly reported community effects; record resting heart rate before and during the cycle.
• One source advises caution alongside GLP-1 agonists, diabetes medications and thyroid medications because of overlapping metabolic effects; no interaction study exists.

How This Works

SLU-PP-332 is a synthetic small molecule, not a peptide, first described by the Burris laboratory at Saint Louis University in 2023–2024. It is a pan-agonist of the estrogen-related receptors ERR-alpha, ERR-beta and ERR-gamma, with the strongest activity at ERR-alpha. The estrogen-related receptors are orphan nuclear receptors that normally switch on after endurance exercise. Activating them upregulates the PGC-1alpha-linked gene programs that drive mitochondrial biogenesis, fatty-acid oxidation and the formation of oxidative type IIa muscle fibers, so the compound mimics some of the metabolic adaptations of aerobic training without exercise. In mice given the compound by intraperitoneal injection, treadmill endurance increased by roughly 70 percent and obese animals lost about 12 percent of body weight over 28 days without a change in diet, with no overt toxicity reported. No human pharmacokinetic or efficacy data exist, the subcutaneous route has not been validated, and the receptors are also active in cardiac tissue, which is the basis of the cardiac caution.

Potential Benefits & Side Effects

Observations from mouse studies; no human data exist.

Potential Benefits:

• About 70 percent longer treadmill run time, with more oxidative type IIa muscle fibers, in mouse studies.
• Enhanced mitochondrial biogenesis and fatty-acid oxidation in skeletal muscle, in mouse studies.
• About 12 percent body-weight and 25–30 percent fat-mass reduction over 28 days in obese mice without a diet change, with improved glucose tolerance and lipids.
• Marketed as an exercise mimetic for endurance, fat loss with muscle preservation and metabolic health; these are claims, not trial results.
• Community reports of energy and endurance, which cannot be separated from placebo without a controlled trial.

Potential Side Effects:

• Community reports: sleep disturbance, elevated resting heart rate, GI discomfort, a feeling of warmth, appetite change, mild headache, fatigue and injection-site reactions.
• Cardiac concern (theoretical and animal): estrogen-related receptors are active in the heart; cardiac hypertrophy has been reported in some higher-dose rodent protocols, along with cardiac substrate switching.
• Injection-site irritation may be more noticeable than with peptides if the solution carries undissolved material or a co-solvent; inspect the solution before every draw.
• Possible interactions with GLP-1 agonists, diabetes medications and thyroid medications, raised by one source without interaction data.
• No human safety data; the long-term effects of ERR activation in humans are unknown.
• Off-target activity at ERR-gamma is noted as a concern by one source.

Lifestyle Factors

Complementary strategies for an endurance and metabolic protocol.

• Keep a structured aerobic training program (150 or more minutes per week) in place; the compound is studied as a mimic of training adaptations, not as a replacement for exercise, and no human data show an effect without training.
• Include resistance training 2–3 days per week and adequate protein (1.2–1.6 g/kg body weight) to preserve lean mass during fat loss.
• Record resting heart rate and sleep quality each morning; these are the two most commonly reported effects and the simplest early warning signs.
• Avoid late-day stimulants such as caffeine after noon, since sleep disturbance is already a reported effect.
• Maintain a modest calorie deficit if fat loss is the goal; the mouse weight-loss data were obtained without a diet change, but no human data support the same effect.
• Stay well hydrated and maintain electrolytes during endurance sessions, particularly when the injection is timed before training.

Injection Technique

General subcutaneous injection guidance from clinical best-practice resources.

• Clean the vial stopper and chosen skin site with separate alcohol swabs; allow both to dry completely before proceeding.
• Pinch a fold of skin between your fingers; insert the needle at a 45–90° angle into the subcutaneous tissue (fatty layer, not muscle).
• Do not aspirate (pull back the plunger) when giving a subcutaneous injection.
• Inject the solution slowly and steadily; wait at least 6 seconds after injection before withdrawing the needle to ensure complete delivery and minimize leakage.
• Withdraw the needle and apply light pressure with a clean swab; avoid rubbing vigorously.
• Rotate injection sites systematically (abdomen, thighs, upper arms) to prevent lipohypertrophy and maintain consistent absorption.
• Dispose of used syringes and needles immediately in a proper sharps container.

Recommended Source

We recommend Amino Labs for high-purity SLU-PP-332 (5 mg vials).

Note: Product availability and specifications subject to change. Verify current product details on supplier website.

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