# The Complete GLP-1 + Mitochondrial Fat Loss Stack: Reta, MOTS-C, SS-31, AOD, and SLU-PP-332
GLP-1 receptor agonists like Retatrutide do a lot of the heavy lifting for fat loss — appetite suppression, improved insulin sensitivity, metabolic rate support. But there's a ceiling to what appetite control alone can accomplish, especially if mitochondrial function is the bottleneck.
A growing number of biohackers are building stacks that pair GLP-1s with mitochondrial peptides: MOTS-C, SS-31, and AOD-9604, sometimes with SLU-PP-332 added for its exercise-mimetic effects. The question people always ask: are these redundant with each other?
The short answer is no. Here's why — and how to actually build the stack.
How Each Compound Works
Before getting into protocols, you need to understand what each compound is actually doing. The "mitochondrial support" label gets applied to all of them, but they're hitting completely different targets.
Retatrutide (GLP-1/GIP/Glucagon Agonist)
Retatrutide is a triple agonist — it hits GLP-1, GIP, and glucagon receptors simultaneously. The GLP-1 component drives satiety and reduces food intake. The GIP component improves insulin sensitivity. The glucagon component increases hepatic fat metabolism and energy expenditure.
This is the foundation of the stack. Everything else layers onto what Reta is already doing.
Dose range: 0.5mg–8mg weekly subQ (most start at 0.5–1mg and titrate up over 8–12 weeks)
MOTS-C (Mitochondrial-Derived Peptide)
MOTS-C is encoded in the mitochondrial genome — it's a mitochondrial-derived peptide (MDP) that the body produces naturally. It activates AMPK (AMP-activated protein kinase), which is the master energy-sensing enzyme. When AMPK is activated, cells switch from fat storage to fat oxidation.
This complements Reta's glucagon component: Reta signals the liver to metabolize more fat, MOTS-C drives fat oxidation at the cellular level throughout the body.
Dose: 250mcg/day for 1–2 weeks, then 500mcg/day subQ. Daily dosing is more effective than EOD — AMPK accumulation is cumulative.
SS-31 (Elamipretide, Mitochondria-Targeted Antioxidant)
SS-31 targets cardiolipin — a phospholipid on the inner mitochondrial membrane that's critical for the electron transport chain. Under metabolic stress (caloric restriction, rapid fat loss, high-volume training), cardiolipin oxidizes and the ETC becomes inefficient. SS-31 binds to and stabilizes cardiolipin, keeping mitochondrial function intact under stress.
In practical terms: when you're in a caloric deficit with rapid fat loss, SS-31 protects the metabolic machinery from oxidative damage. It makes Reta's weight loss more efficient by preventing mitochondrial dysfunction as body fat decreases.
Dose: 5–10mg subQ, daily or 5 days on/2 off. Evening timing is smart — mitochondrial repair happens during sleep.
AOD-9604 (HGH Fragment 176–191)
AOD-9604 is a 16-amino acid fragment of human growth hormone that retains HGH's lipolytic (fat-burning) properties without the anabolic, IGF-1-stimulating, or glucose-raising effects of full HGH.
It activates β3-adrenergic receptors in fat tissue, increasing fat cell lipase activity. This is a different fat-loss pathway than GLP-1/GIP/glucagon — it acts directly on adipocyte lipolysis.
Dose: 300mcg/day subQ, fasted morning. 5 days on/2 off or daily. 8–12 week cycles.
SLU-PP-332 (ERRα Agonist)
SLU-PP-332 is a small molecule (not a peptide) that activates ERRα (estrogen-related receptor alpha), a transcription factor that drives expression of genes involved in mitochondrial biogenesis — particularly downstream of PGC-1α. In animal studies, it produced significant improvements in endurance capacity and fat oxidation without exercise.
Where MOTS-C activates AMPK (the signal), SLU-PP-332 activates ERRα (the gene expression). They work at different levels of the same pathway: MOTS-C sends the metabolic stress signal, SLU-PP-332 drives the transcriptional response that builds more mitochondrial capacity.
Dose: 5–20mg/day oral (small molecule — oral bioavailability is ~40–50%, so oral is the preferred route). Take in the morning, ideally before exercise or fasted cardio.
Why These Aren't Redundant
People worry that stacking MOTS-C, SS-31, and SLU-PP-332 is redundant because they all "support mitochondria." Here's why that concern doesn't hold:
| Compound | Primary Target | Mechanism |
|---|---|---|
| Retatrutide | GLP-1/GIP/Glucagon receptors | Satiety + insulin sensitivity + hepatic fat metabolism |
| MOTS-C | AMPK (mitochondrial mt-ORF pathway) | Energy sensing, fat oxidation signal |
| SS-31 | Cardiolipin (inner mitochondrial membrane) | Membrane protection, ETC efficiency under stress |
| AOD-9604 | β3-adrenergic receptors (fat tissue) | Direct adipocyte lipolysis |
| SLU-PP-332 | ERRα (transcription factor) | Mitochondrial biogenesis gene expression |
The simplest way to think about it:
- MOTS-C sends the signal ("we need more fat burning")
- SLU-PP-332 drives the genetic expression ("build more mitochondrial capacity")
- SS-31 protects what you have from oxidative damage
- AOD-9604 acts independently on fat cell lipolysis
- Retatrutide controls the whole system from the appetite/hormonal side
These are additive, not redundant.
The Stack Protocol
Phase 1: Establish the GLP-1 Foundation (Weeks 1–4)
Before adding anything, get Retatrutide dialed in. Titrate from your starting dose, manage side effects, and establish your caloric approach. Starting too many compounds at once makes it impossible to identify what's causing what.
- Retatrutide: titrate per your protocol (0.5–1mg/week start)
- No other compounds yet
Phase 2: Add Mitochondrial Support (Weeks 4–6)
Once Reta is stable, layer in the mitochondrial compounds:
Week 4: Add MOTS-C at 250mcg/day subQ (1–2 weeks at this dose before increasing)
Week 5: Add SS-31 at 5mg/day subQ (evening preferred)
Week 6: Increase MOTS-C to 500mcg/day
Phase 3: Add AOD and SLU-PP-332 (Weeks 7–8 onward)
Week 7: Add AOD-9604 at 300mcg/day subQ, fasted morning
Week 8: Add SLU-PP-332 at 5–10mg/day oral, morning
Monitor energy levels. At this point you have a significant metabolic stack — some people notice increased energy demands (hunger signal from higher expenditure, not from food noise returning). Ensure protein intake is adequate (1.8–2g/kg minimum).
Daily Schedule
| Time | Compound | Notes |
|---|---|---|
| Morning (fasted) | AOD-9604 300mcg subQ | Wait 30 min before eating |
| Morning | SLU-PP-332 5–10mg oral | Pre-cardio or with first meal |
| Morning/midday | MOTS-C 500mcg subQ | Any time, consistent daily |
| Evening | SS-31 5mg subQ | Before bed preferred |
| Weekly | Retatrutide per titration | Per your protocol |
Common Questions
Q: Can I start MOTS-C and SS-31 at the same time?
Yes — they have different mechanisms and no known interactions. Some people prefer starting MOTS-C first for 1–2 weeks to establish baseline, but simultaneous start is fine.
Q: Is SLU-PP-332 worth adding if I'm already running MOTS-C?
Yes — they work at different levels of the same pathway. If budget is a constraint, MOTS-C + SS-31 is the higher-priority pair. Add SLU-PP-332 when you're ready to push further.
Q: What if I'm not losing weight despite running this full stack?
First check the basics: total caloric intake (GLP-1s can mask hunger but not physics), protein target (adequate protein prevents muscle loss which would reduce metabolic rate), and sleep quality (poor sleep elevates cortisol which counteracts GLP-1 effects). If all those are dialed in, check if you're still in a titration window — most people see strongest satiety at 3mg+ weekly on Reta.
Q: Do I need to cycle any of these?
MOTS-C: 8–12 weeks on, 4 weeks off (or 5on/2off continuously) — receptor sensitivity consideration. SS-31: can run continuously, no established need to cycle. AOD-9604: 8–12 week cycles with a break. SLU-PP-332: no established cycling protocol, but 8–12 weeks on/4 off is prudent given limited human data. Reta: per your GLP-1 protocol.
Q: Where do I source these?
For US-based sourcing, American Peptide Research (APR) carries most of these compounds: americanpeptideresearch.net/ref/126/
Q: How do I know if the stack is working?
Track subjective energy levels (MOTS-C effect usually felt weeks 2–3), waist measurements (not just scale weight — Reta can cause water retention at dose increases), fasted energy (SLU-PP-332 + MOTS-C combination often produces noticeable Zone 2 cardio improvement), and recovery from training (SS-31 effect on workout-to-workout recovery).
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