| At a Glance | |
|---|---|
| Who it's for | Experienced users training 4+ days/week who want to gain muscle while losing fat |
| Duration | 12 weeks |
| Key components | Retatrutide (1–4 mg/wk), NAD+, L-Carnitine, MOTS-c, Tesamorelin |
| Results timeline | Visible recomposition by week 4; +5-10lb of lean mass and 10+ lb fat loss by week 12 |
| Difficulty | Advanced |
This is an advanced-level protocol. It assumes consistent training (4+ days per week), adequate protein intake, and discipline with multi-compound stacks. For a simpler starting point, see the Retatrutide + NAD Beginner Protocol.
The Problem with GLP-1 Monotherapy
GLP-1 agonists work—the appetite suppression is real, the deficit follows. But something is wrong with the outcomes.
People are lighter but weaker. Thinner but exhausted. The scale moves, but energy doesn't follow. In clinical trials, lean tissue accounts for a significant portion of weight lost: approximately 40% with semaglutide (STEP-1 DXA, 68 weeks) and 25% with tirzepatide (SURMOUNT-1 DXA, 72 weeks). For someone losing fifty pounds on semaglutide without countermeasures, that's roughly twenty pounds of muscle gone.
GLP-1 drugs create deficits by suppressing appetite. But a deficit is pressure, not direction. Without signals telling the body what to burn, it burns both fat and muscle.
Weight loss requires two axes working together:
- Central axis — appetite, intake behavior, the decision to eat. GLP-1s address this effectively.
- Peripheral axis — oxidation machinery, mitochondrial capacity, the ability to burn what's been mobilized. GLP-1s ignore this axis—semaglutide and tirzepatide actively impair it by suppressing glucagon.
This is why GLP-1 monotherapy produces weight loss but not recomposition.
Why Retatrutide Is Different
Retatrutide activates three receptors: GLP-1, GIP, and glucagon. The first two provide appetite suppression and glycemic smoothing. The third—glucagon—is what separates retatrutide from its predecessors.
Glucagon receptor activation preserves the liver's fat oxidation. Resting energy expenditure rises rather than falls. Fat is mobilized and burned, not just stored less.
At high doses (8–12 mg), retatrutide behaves as a bariatric drug. But this protocol uses retatrutide differently: as a low-dose metabolic stabilizer (1–4 mg), creating the foundation for directed fat loss while other compounds build oxidation capacity.
The Fat-Burning Chain
Fat burning is not one step. It is a chain, and every link must be present:
- Retatrutide → releases fat from storage (mobilization)
- L-Carnitine → transports fat into mitochondria (logistics)
- MOTS-c → programs mitochondria to prefer fat (the switch)
- NAD+ → provides capacity to complete combustion (execution)
Skip any link and the chain weakens.
Retatrutide Mobilizes Fat
The glucagon arm signals adipose tissue to release fatty acids and primes the liver for oxidation. Fat leaves storage and enters the bloodstream. But fat circulating in blood is not fat being burned.
L-Carnitine Transports Fat
Long-chain fatty acids cannot cross the inner mitochondrial membrane on their own. They require the carnitine shuttle. Without adequate carnitine, fatty acids accumulate outside the furnace, unavailable for burning.
MOTS-c Programs Mitochondria
Here's what most approaches miss: fat sitting inside mitochondria is not the same as fat being oxidized.
Mitochondria can burn either glucose or fat. In metabolically inflexible individuals, the system is biased toward glucose. Fat may be present, transported, available, but the machinery isn't set up to prefer it.
MOTS-c is a mitochondrial-derived peptide that activates AMPK, the energy sensor that detects active fuel burning. AMPK triggers pathways that shift cellular preference toward fat oxidation. The mitochondria stop waiting for glucose and start burning what's available.
This is not stimulation. It is reprogramming.
NAD+ Completes Combustion
Once mitochondria are programmed to prefer fat, they need cofactor capacity to complete β-oxidation. NAD+ is required at every step. Without adequate NAD+ pools, the chain stalls at the final step—fat is mobilized, transported, programmed for burning, but cannot complete the process.
The subjective experience is fatigue, brain fog, and the sense of being "wired but underpowered."
Understand why NAD+ is a critical support layer for GLP-1s.
The Anabolic Layer: Tesamorelin
The first four layers create a deficit and route it toward fat. But they do not actively protect lean tissue. Under strong catabolic pressure, muscle can still be sacrificed.
Tesamorelin adds the anabolic counterweight. It's a GHRH analog that restores pulsatile growth hormone secretion rather than supplying exogenous GH. The distinction matters: tesamorelin preserves the body's natural rhythm rather than flattening it.
In clinical trials, tesamorelin produces selective effects:
- Visceral adipose tissue decreases
- Lean mass is preserved or modestly increased
- Hepatic fat fraction drops
The visceral fat reduction creates a feedback loop. Visceral fat secretes inflammatory cytokines, worsens insulin resistance, and impairs fuel-routing. As visceral fat decreases, insulin sensitivity improves, and the fat-as-fuel bias becomes easier to maintain.
Circadian alignment matters: GH secretion is naturally nocturnal. Tesamorelin amplifies this pattern, supporting a clean division — daytime for AMPK-dominant oxidation, nighttime for mTOR-dominant repair.
Alternatives and Add-Ons
Ipamorelin is a selective GH secretagogue that can substitute tesamorelin if GHRH analogs are unavailable. It stimulates pulsatile GH release through the ghrelin receptor without affecting cortisol, prolactin, or aldosterone — a cleaner selectivity profile than older secretagogues. Dosing: 200–300 mcg SubQ before bed. It can also be combined with tesamorelin for synergistic GH release (GHRH + GHS produce greater-than-additive pulses).
AOD-9604 targets stubborn subcutaneous fat depots directly. It's the lipolytic fragment of growth hormone (amino acids 176–191) — it signals fat cells to mobilize stored energy without raising IGF-1 or affecting insulin sensitivity. Clinical efficacy as a standalone is modest (~2% net difference in Phase 2b), but as a fine-tuning adjunct layered on top of the oxidation chain, it addresses the last-mile problem of resistant fat deposits. Dosing: 300 mcg SubQ fasted AM. Has FDA GRAS status as a food ingredient, reflecting favorable safety review.
Dosing
Use the reconstitution calculator to determine exact injection volumes for each compound.
| Compound | Dose | Frequency | Route | Timing | Notes |
|---|---|---|---|---|---|
| Retatrutide | 1–4 mg | Weekly or every 3d | SubQ | — | Allow 4+ weeks before increasing |
| NAD+ | 100–200 mg | EOD or 5×/week | IM or SubQ | Morning | — |
| L-Carnitine | 500 mg | 5–7×/week | IM | Fasted, or pre-training | — |
| MOTS-c | 5–10 mg | 2–3×/week | SubQ | Fasted, pre-training | See cycling protocol below |
| Tesamorelin | 1–2 mg | Nightly | SubQ | Before sleep, 2+ hrs after last meal | Monitor IGF-1 at weeks 4 and 12 |
Weekly Schedule (Example)
| Compound | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|---|
| Retatrutide | 2 mg | — | — | 2 mg | — | — | — |
| NAD+ | 150 mg | 150 mg | 150 mg | 150 mg | 150 mg | — | — |
| L-Carnitine | 500 mg | 500 mg | 500 mg | 500 mg | 500 mg | opt | — |
| MOTS-c | 10 mg | — | 10 mg | — | 10 mg | — | — |
| Tesamorelin | 2 mg | 2 mg | 2 mg | 2 mg | 2 mg | 2 mg | 2 mg |
MOTS-c Cycling
MOTS-c activates AMPK–PGC1α transcription for ~72 hours. An activated pathway does not need re-activation. Little benefit is gained by increasing frequency.
| Phase | Duration | Protocol |
|---|---|---|
| On | 6–8 weeks | 5–10 mg, 2–3×/week |
| Off | 2–4 weeks | Continue other compounds |
Lifestyle Foundation
| Component | Target |
|---|---|
| Protein | 1.0–1.2 g/lb body weight; 30–40 g per meal |
| Carbohydrates | Increased intake of fruit before training |
| Training | 4–5 days/week; resistance + Zone 2 cardio |
| Cardio timing | Fasted morning after L-Carnitine for optimal oxidation |
| Sleep | 7–9 hours; Tesamorelin timing requires consistent bedtime |
| Hydration | 3–4 liters daily |
Timeline: What to Expect
Weeks 1–4
- GH adaptation — Sleep deepens within first week
- Fat loss — Accelerates to 1–2 lb/week
- Recovery — Training recovery noticeably faster
- Water — GH-related retention may occur; resolves by week 3–4
- Muscle — Fullness maintained despite deficit
Weeks 5–8
- Recomposition — Visible transformation: waist drops, limbs hold or gain size
- Performance — Strength maintained or improved; endurance up
- Visceral fat — Belt notches move; trunk tightens
- Energy — Higher than pre-protocol baseline despite lower calories
Weeks 9–12
- Definition — Muscle separation apparent; stubborn areas yielding
- Cumulative — 10+ lb fat loss typical; lean mass preserved or gained
- Metabolic markers — Significant improvements in glucose, TG, HDL, liver enzymes
- State — Metabolism feels self-sustaining, not effortful
When Progress Stalls
| Step | Action |
|---|---|
| 1 | Verify protein intake, steps, and sleep quality |
| 2 | Increase L-Carnitine to 1000 mg/day if below |
| 3 | After 4+ weeks stable, raise retatrutide by 0.5 mg/week |
| 4 | Move NAD+ to 250 mg per dose |
| 5 | Add one Zone 2 cardio session |
| 6 | For stubborn subcutaneous fat: consider AOD-9604 300 mcg fasted AM |
Managing Side Effects
GH-Related (Tesamorelin)
| Issue | Management |
|---|---|
| Water retention (weeks 1–3) | Transient; ensure adequate potassium |
| Joint stiffness / hand paresthesia | Improves with movement; reduce dose if persistent |
| Blood glucose elevation | Monitor if diabetic; GH can transiently raise fasting glucose |
Retatrutide-Related
| Issue | Management |
|---|---|
| Nausea/early satiety | Smaller protein-first meals; hold dose |
| Constipation | Fiber + fluids → magnesium citrate |
MOTS-c/L-Carnitine
| Issue | Management |
|---|---|
| Early fatigue (MOTS-c) | Unlikely but resolves; ensure sleep and electrolytes |
| Injection site soreness | Rotate sites; use appropriate needle length |
Monitoring
| Timepoint | What to Track |
|---|---|
| Baseline | CBC, CMP, lipids, fasting glucose/insulin, HbA1c, thyroid, IGF-1 |
| Week 4 | IGF-1 (target 50–100% above baseline, not supraphysiologic), fasting glucose |
| Monthly | IGF-1 while on Tesamorelin |
| Week 12 | Full panel; expect: ↓ glucose, ↓ TG, ↑ HDL, ↑ IGF-1, improved liver enzymes |
IGF-1 guidance: Target physiologic elevation. If IGF-1 exceeds 350–400 ng/mL, reduce Tesamorelin dose.
What Comes Next
Maintenance:
- Reduce retatrutide to 2-4 mg/week
- Tesamorelin to 1 mg nightly for sleep/connective tissue support
- NAD+ at 100–150 mg 2-3x a week
- L-Carnitine pre-training as needed
Lean-gain phase:
- Reduce retatrutide to minimal 1-2mg/week
- Maintain Tesamorelin
- Increase calories to slight surplus
- Continue NAD+ and L-Carnitine
- Goal: slow, clean accrual of lean mass
Contraindications
- Personal or family history of medullary thyroid carcinoma or MEN2 syndrome
- Active malignancy (GH/IGF-1 axis; MOTS-c)
- Proliferative diabetic retinopathy
- Pregnancy or breastfeeding
- Uncontrolled diabetes (requires close monitoring)
FAQ
Why use low-dose retatrutide instead of full dose?
Full-dose retatrutide (8–12 mg) is a powerful deficit creator but can overwhelm fat oxidation capacity. Low-dose (1–4 mg) mobilizes fat without collapsing metabolic rate, while other compounds build the machinery to burn what's released.
Can I skip the anabolic layer (Tesamorelin)?
You can, but expect more lean mass loss. Tesamorelin provides the growth hormone signal that protects muscle during aggressive deficits and improves visceral fat targeting.
How do I know if the protocol is working?
Track waist circumference and strength performance, not just scale weight. Recomposition often shows as stable or dropping weight with maintained or increased strength and smaller waist.
What happens after 12 weeks?
Transition to maintenance (lower doses) or a lean-gain phase (reduce retatrutide to 1–2 mg/week, maintain tesamorelin, slight caloric surplus). The metabolic improvements persist if habits are maintained.
What does MOTS-c do in this protocol?
MOTS-c is a mitochondrial-derived peptide that activates AMPK, the cellular energy sensor that shifts fuel preference toward fat oxidation. In this stack, retatrutide mobilizes fat and L-Carnitine transports it into mitochondria, but without MOTS-c the mitochondria may still default to burning glucose. MOTS-c reprograms that preference so the machinery actually burns the fat that has been delivered to it.
MOTS-c is dosed 2-3 times per week because it activates the AMPK-PGC1α transcription pathway for approximately 72 hours per dose. The protocol cycles it 6-8 weeks on, 2-4 weeks off, while other compounds continue.
Why isn't oral L-Carnitine part of this stack?
Long-chain fatty acids cannot cross the inner mitochondrial membrane on their own — they require the carnitine shuttle system to get inside the furnace. When retatrutide's glucagon arm mobilizes fat from storage, that fat enters the bloodstream but is not yet being burned. Without adequate carnitine, fatty acids accumulate outside the mitochondria, unavailable for oxidation.
This protocol uses injectable L-Carnitine (500 mg IM, fasted or pre-training) rather than oral because intramuscular delivery bypasses the gut absorption limitations that make oral carnitine less reliable. If progress stalls, the protocol calls for increasing to 1000 mg per day.
Why does NAD+ matter during aggressive fat loss?
NAD+ is a cofactor required at every step of beta-oxidation — the metabolic process that breaks down fatty acids inside mitochondria. When the rest of this stack successfully mobilizes, transports, and programs fat for burning, inadequate NAD+ pools cause the chain to stall at the final step. The subjective experience is fatigue, brain fog, and feeling "wired but underpowered" — fat is being released but the body cannot finish burning it.
Aggressive deficits also deplete NAD+ faster than normal. This protocol uses 100–200 mg injected EOD or 5 days per week in the morning, with the option to increase to 250 mg if energy flags. During the maintenance phase after week 12, NAD+ drops to 100–150 mg 2–3 times a week.
Related Topics
- GLP-1 Compounds Tool — interactive comparison with trial data on weight loss and composition
- Retatrutide + NAD Beginner Protocol — simpler starting point
- Retatrutide Guide — mechanism, trials, and safety data
- Tesamorelin Guide — the anabolic layer explained
- AOD-9604 Guide — optional lipolytic support for stubborn areas
- NAD+ Guide — cofactor support for fat oxidation
- MOTS-c Guide — mitochondrial programming peptide
- MITT-Stack White Paper — mitochondrial peptide deep-dive
- GLP-1 Muscle Preservation — body composition strategies
- GLP-1 Comparison — how agents compare
- Semaglutide Guide — The established GLP-1 benchmark for comparison
- Tirzepatide Guide — Dual-agonist — intermediate between semaglutide and retatrutide
- Reconstitution Guide — How to prepare each vial in the protocol
References
- Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity. NEJM 2023. DOI: 10.1056/NEJMoa2301972
- Stanley TL, et al. Effects of Tesamorelin on Non-Alcoholic Fatty Liver Disease. Lancet HIV 2019. DOI: 10.1016/S2352-3018(19)30338-8
- Lee C, et al. The Mitochondrial-Derived Peptide MOTS-c Promotes Metabolic Homeostasis. Cell Metabolism 2015. DOI: 10.1016/j.cmet.2015.02.009
- Stephens FB, et al. Skeletal Muscle Carnitine Loading Increases Energy Expenditure. Journal of Physiology 2013. DOI: 10.1113/jphysiol.2013.255364
- Yoshino J, et al. NAD+ Intermediates: The Biology and Therapeutic Potential. Cell Metabolism 2021. DOI: 10.1016/j.cmet.2020.11.007
Medical Disclaimer
The content in this protocol guide is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before beginning any new protocol, supplement, or medication.