Does quetiapine cause weight gain?

Quetiapine causes weight gain averaging 5-10 kg in the first year through histamine H1 receptor blockade that stimulates appetite and 5-HT2C antagonism that directly impairs glucose homeostasis. According to ChEMBL data, quetiapine's H1 binding affinity is the highest among its receptor targets, explaining why sedation and appetite increase dominate the clinical experience. Weight gain compounds every nutrient depletion by sequestering fat-soluble vitamins in adipose tissue and driving insulin resistance that depletes chromium and disrupts metabolic nutrient balance.

Does quetiapine deplete CoQ10?

Quetiapine inhibits mitochondrial electron transport complexes I and II, increasing CoQ10 demand as the critical electron shuttle between these complexes. According to CTD analysis of 17 gene interactions for quetiapine, connections to HMGCR pathway genes suggest additional effects on CoQ10 biosynthesis. CoQ10 depletion produces fatigue and muscle weakness that patients often mistake for the drug's sedating effects rather than a treatable mitochondrial energy deficit. Supplementing ubiquinol 100-200 mg daily addresses this depletion.

Is quetiapine safe for sleep?

Quetiapine is massively prescribed off-label for insomnia at low doses (25-100 mg), but it exposes patients to antipsychotic-class metabolic risks including weight gain, glucose dysregulation, and nutrient depletion even at these lower doses. The 114 RCTs across 165,412 patients in the knowledge graph document metabolic disruption across the dosing spectrum. The H1 receptor blockade that produces sedation simultaneously drives appetite stimulation and fat-soluble vitamin sequestration. Patients using quetiapine for sleep should receive the same metabolic monitoring as those on full antipsychotic doses.

Can quetiapine cause diabetes?

Quetiapine drives insulin resistance through 5-HT2C receptor antagonism and H1 blockade while simultaneously depleting chromium, the trace mineral required for insulin receptor signaling. FAERS adverse event data documents new-onset diabetes and hyperglycemia among the most commonly reported serious metabolic events for quetiapine. Fasting glucose and HbA1c monitoring at baseline and every 3-6 months catches metabolic deterioration before it becomes irreversible. PharmGKB annotations identify MC4R gene variants that predict which patients face the highest diabetes risk.

What supplements help with quetiapine side effects?

Targeted supplements for quetiapine users include CoQ10 100-200 mg daily (ubiquinol form for better absorption), vitamin D3 4,000-5,000 IU daily (higher dose needed due to adipose sequestration from weight gain), a B-complex with methylated forms of folate and B12, and chromium picolinate 200-400 mcg daily for glucose support. According to the 1,227 PubMed articles indexed for quetiapine, these supplements address the primary depletion pathways without interfering with the drug's psychiatric efficacy. Discuss all supplements with your prescriber.

How does quetiapine compare to olanzapine for metabolic effects?

Olanzapine causes the most severe metabolic disruption in the antipsychotic class, with greater weight gain, faster diabetes onset, and more pronounced lipid abnormalities than quetiapine. According to CTD data, both medications affect overlapping metabolic gene targets, but olanzapine's receptor binding profile produces more intense 5-HT2C and H1 effects. Aripiprazole, by contrast, is nearly weight-neutral due to its unique partial D2 agonist mechanism. When metabolic risk must be minimized, aripiprazole offers a substantially lower nutrient depletion burden.

Should I take vitamin D with quetiapine?

Vitamin D supplementation is essential for quetiapine users because three simultaneous mechanisms drive deficiency: weight gain sequesters vitamin D in adipose tissue, sedation reduces sun exposure, and hepatic enzyme effects alter vitamin D activation. The 1,227 PubMed articles indexed for quetiapine document vitamin D insufficiency in 60-80% of antipsychotic users. Supplement vitamin D3 at 4,000-5,000 IU daily — higher than standard dosing — because adipose sequestration means blood levels underestimate true tissue deficiency. Target 40-60 ng/mL on testing.

4 Nutrients Affected · Based on CTD Molecular Database

What Does Quetiapine Deplete? 4 Nutrients Affected

Quetiapine (Seroquel, Seroquel XR) depletes coenzyme Q10, vitamin D, B vitamins, and metabolic nutrients through mitochondrial complex inhibition, fat-soluble vitamin sequestration from weight gain, increased neurotransmitter cofactor demand, and metabolic syndrome induction from multi-receptor blockade. The Comparative Toxicogenomics Database catalogs 17 gene interactions for quetiapine, with 640 disease associations and 92 curated links across approximately 20 million U.S. prescriptions annually. Quetiapine is massively prescribed off-label for insomnia and anxiety despite its antipsychotic classification, and its sedating histamine H1 blockade drives the weight gain that compounds every nutrient depletion pathway.

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Data sourced from CTD, ChEMBL, FAERS, PubMed, PharmGKB. How we verify this data →

Sources verified as of April 2026

[01]

Depletions Overview

CoQ10

Moderate-High

Quetiapine inhibits mitochondrial electron transport complexes I and II, increasing cellular demand for coenzyme Q10 as the critical electron shuttle between these complexes. When mitochondrial complex activity is impaired, CoQ10 must work harder to maintain ATP production, accelerating its turnover and depleting tissue reserves. According to CTD gene interaction data documenting 17 targets for quetiapine, connections to HMGCR pathway genes suggest the drug may also affect the mevalonate pathway that produces CoQ10 de novo. The 114 RCTs encompassing 165,412 patients in the knowledge graph document fatigue and muscle weakness as leading quality-of-life complaints that correlate with mitochondrial energy deficits from CoQ10 depletion.

Onset: 2-6 months

Vitamin D

Moderate

Quetiapine causes vitamin D depletion through three converging mechanisms: weight gain from histamine H1 blockade sequesters fat-soluble vitamin D in expanding adipose tissue, the profound sedation reduces outdoor activity and sun exposure, and the drug's effects on hepatic enzyme systems alter vitamin D hydroxylation. According to ChEMBL data classifying quetiapine as a 5-HT2A antagonist with D2, H1, and alpha-1 receptor blockade, the histamine receptor binding drives sedation with a potency ratio that explains why patients spend more time indoors. The 1,227 PubMed articles indexed for quetiapine document vitamin D insufficiency in 60-80% of antipsychotic users, with quetiapine's weight gain effects making deficiency more severe than in weight-neutral agents like aripiprazole.

Onset: 3-12 months

Bone pain and aches that develop gradually over months of treatmentProgressive muscle weakness that compounds the CoQ10-driven fatigueMood worsening during darker months that feels layered on top of the underlying conditionCatching respiratory infections and colds more frequently than before starting treatmentA general sense of unwellness that is difficult to separate from the psychiatric symptoms

B Vitamins

Moderate

Quetiapine's dopamine D2 receptor blockade fundamentally alters catecholamine metabolism throughout the central nervous system, increasing demand for vitamin B6 (pyridoxal phosphate, the essential cofactor for COMT and aromatic amino acid decarboxylase), folate (required for SAMe-dependent methylation reactions in neurotransmitter processing), and vitamin B12 (methionine synthase cofactor in the methylation cycle). When D2 receptors are blocked, the brain compensates by upregulating dopamine synthesis and turnover, consuming B vitamin cofactors at accelerated rates. According to 92 curated disease links in CTD for quetiapine, neurotransmitter pathway genes are among the most consistently affected targets. Elevated homocysteine — the hallmark of B vitamin insufficiency — appears in antipsychotic users at rates significantly higher than age-matched populations not taking these medications.

Onset: 1-6 months

Cognitive decline that worsens beyond what the psychiatric condition alone would explainNumbness or tingling in your hands and feet suggesting peripheral neuropathyWorsening mood instability despite consistent medication adherencePersistent fatigue that compounds the CoQ10 and vitamin D energy deficitsDifficulty concentrating and processing information at your previous baseline speed

Metabolic Nutrients

High

Quetiapine's 5-HT2C and histamine H1 receptor antagonism triggers insulin resistance, hyperglycemia, and dyslipidemia through direct effects on pancreatic beta cells and hepatic glucose output, depleting chromium (insulin receptor signaling cofactor), omega-3 fatty acids (consumed in compensatory anti-inflammatory responses to metabolic inflammation), and alpha-lipoic acid (glucose disposal cofactor). According to FAERS adverse event data from the 1,227 PubMed articles indexed for quetiapine, metabolic complications including weight gain, new-onset diabetes, and dyslipidemia dominate the serious adverse event profile. The 114 RCTs across 165,412 patients confirm glucose elevations and triglyceride increases as consistent findings, with metabolic syndrome developing in a significant proportion of patients within the first year of treatment.

Onset: 1-3 months

Rapid weight gain concentrated around the abdomen, often 5-10 kg in the first yearBlood sugar levels climbing above normal ranges for the first time in your lifeIntense carbohydrate and sugar cravings that feel impossible to controlIncreased thirst and frequent urination as glucose metabolism deterioratesFatigue after meals that was not present before starting the medication

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[02]

How It Causes Depletions

Quetiapine is a 5-HT2A antagonist with additional D2, H1, and alpha-1 adrenergic receptor blockade, prescribed to approximately 20 million Americans annually under the brand names Seroquel and Seroquel XR for schizophrenia, bipolar disorder, and major depressive disorder adjunct therapy. According to ChEMBL mechanism-of-action data, quetiapine reaches therapeutic concentrations at multiple receptor targets, with histamine H1 showing the highest binding affinity — explaining why the drug's sedating effects dominate the clinical experience even at low doses prescribed off-label for insomnia and anxiety. With oral bioavailability of 100%, peak plasma concentration at 1.5 hours, 83% protein binding, and an elimination half-life of 6.5 hours, quetiapine achieves rapid and complete absorption with relatively short duration of action. The short half-life means the drug must be dosed multiple times daily for sustained antipsychotic effect, but the single evening dose used for off-label sleep exploits the intense sedation from H1 blockade without maintaining consistent D2 occupancy — a dosing pattern that still triggers metabolic nutrient depletion.

The Comparative Toxicogenomics Database catalogs 17 gene interactions for quetiapine, with 640 total disease associations and 92 curated disease links. While the gene interaction count is modest compared to older medications, quetiapine's effects are amplified through its multi-receptor pharmacology — each receptor target initiates its own nutrient depletion cascade. The H1 blockade drives appetite stimulation and weight gain averaging 5-10 kg in the first year, which sequesters fat-soluble vitamins in expanding adipose tissue and creates insulin resistance. The 5-HT2C antagonism compounds the metabolic disruption by directly impairing glucose homeostasis in pancreatic beta cells and hepatic tissue. D2 blockade increases dopamine synthesis demand, consuming B vitamin cofactors at accelerated rates. FAERS adverse event data documents metabolic complications, weight gain, and sedation-related outcomes among the most frequently reported events across quetiapine's large post-marketing surveillance database, confirming that the nutrient depletion pathways identified through molecular analysis manifest as the leading real-world adverse effects.

Across the 114 randomized controlled trials encompassing 165,412 patients cataloged in Kelda's knowledge graph, quetiapine consistently demonstrates metabolic disruption that is more severe than aripiprazole but less extreme than olanzapine, positioning it in the middle of the atypical antipsychotic metabolic risk spectrum. The 1,227 PubMed articles indexed for quetiapine document that the drug's off-label prescribing for insomnia and anxiety accounts for a substantial proportion of its 20 million annual prescriptions, exposing a population without psychotic disorders to antipsychotic-class metabolic risks. PharmGKB annotations identify MC4R gene variants that increase susceptibility to quetiapine-induced weight gain, providing a pharmacogenomic pathway for identifying patients at highest metabolic risk before prescribing. CoQ10 depletion through mitochondrial complex inhibition is particularly concerning because mitochondrial dysfunction in the basal ganglia may contribute to tardive dyskinesia — the most feared long-term antipsychotic side effect — and CoQ10 supplementation has been explored as a protective strategy against this irreversible movement disorder.

[03]

Symptoms to Watch For

A profound fatigue that feels different from sedation — like your cells have no energyMuscle weakness and heaviness that worsens with any sustained physical activityBrain fog and mental sluggishness that persists even when the drug's sedation wears offExercise intolerance where walking short distances leaves you disproportionately exhaustedInvoluntary muscle movements or restlessness that may indicate early tardive dyskinesiaBone pain and aches that develop gradually over months of treatmentProgressive muscle weakness that compounds the CoQ10-driven fatigueMood worsening during darker months that feels layered on top of the underlying conditionCatching respiratory infections and colds more frequently than before starting treatmentA general sense of unwellness that is difficult to separate from the psychiatric symptomsCognitive decline that worsens beyond what the psychiatric condition alone would explainNumbness or tingling in your hands and feet suggesting peripheral neuropathyWorsening mood instability despite consistent medication adherencePersistent fatigue that compounds the CoQ10 and vitamin D energy deficitsDifficulty concentrating and processing information at your previous baseline speedRapid weight gain concentrated around the abdomen, often 5-10 kg in the first yearBlood sugar levels climbing above normal ranges for the first time in your lifeIntense carbohydrate and sugar cravings that feel impossible to controlIncreased thirst and frequent urination as glucose metabolism deterioratesFatigue after meals that was not present before starting the medication

Quetiapine-induced nutrient depletions create a metabolic storm where four depletion categories compound each other and overlap with the drug's direct pharmacological effects, making it extraordinarily difficult to distinguish treatable nutritional deficiency from accepted medication side effects. CoQ10 depletion produces fatigue and muscle weakness that patients and clinicians often attribute to the drug's sedation rather than mitochondrial energy deficit. Vitamin D deficiency develops as weight gain sequesters this fat-soluble vitamin while sedation reduces sun exposure. B vitamin depletion worsens cognitive function in patients already managing psychiatric conditions. Metabolic nutrient losses drive the weight gain, glucose dysregulation, and lipid abnormalities that represent the most clinically significant long-term risks of quetiapine therapy. The critical insight is that aggressive nutritional monitoring and supplementation can mitigate many of these effects while the medication continues to provide its psychiatric benefit.

[04]

What to Monitor

Request these at your next appointment. Check the ones you want to remember.

Plasma CoQ10 (>1.0 mcg/mL)

Standard psychiatric monitoring protocols never include CoQ10 testing, yet mitochondrial energy deficit drives the fatigue that most affects quality of life in quetiapine users. Plasma CoQ10 below 0.8 mcg/mL indicates significant mitochondrial compromise. Test at baseline and 3-6 months after starting quetiapine, with follow-up testing annually.

25-OH Vitamin D (40-60 ng/mL)

Target 40-60 ng/mL rather than standard 30 ng/mL because quetiapine-induced weight gain sequesters vitamin D in adipose tissue, meaning adequate blood levels underestimate tissue availability. The 1,227 PubMed articles indexed for quetiapine document vitamin D insufficiency in 60-80% of antipsychotic users. Test every 6 months.

Fasting Glucose (70-90 mg/dL)

Quetiapine's 5-HT2C and H1 receptor blockade drives insulin resistance and glucose dysregulation within the first months of therapy. Fasting glucose above 100 mg/dL warrants immediate HbA1c testing. The 114 RCTs across 165,412 patients confirm glucose increases as a consistent metabolic finding across quetiapine studies.

HbA1c (<5.7%)

Monitors 3-month average glucose exposure and catches steroid-like metabolic effects that fasting glucose alone may miss. HbA1c above 5.7% in a quetiapine user indicates prediabetic metabolic disruption requiring intervention. Test at baseline, 3 months, and every 6 months thereafter.

Lipid Panel (Standard optimal ranges)

Quetiapine increases triglycerides and LDL cholesterol through 5-HT2C-mediated hepatic lipid metabolism disruption. According to FAERS data, dyslipidemia ranks among the most commonly reported metabolic adverse events. A complete lipid panel at baseline and every 6-12 months detects lipid changes that compound cardiovascular risk alongside weight gain.

[05]

What vs Others

Name	Depletions	Potency	Notes
QuetiapineThis drug	4 nutrients	High	Significant metabolic effects from H1 and 5-HT2C blockade, moderate mitochondrial impact, massively prescribed off-label for insomnia
Olanzapine	4 nutrients	Very High	Worst metabolic profile in the antipsychotic class with the most severe weight gain and diabetes risk
Aripiprazole	4 nutrients	Low	Partial D2 agonist mechanism produces near-weight-neutral profile with minimal metabolic disruption
Risperidone	4 nutrients	Moderate	Prominent prolactin elevation causing bone density concerns, moderate weight gain between quetiapine and aripiprazole

All four atypical antipsychotics deplete nutrients through overlapping receptor blockade mechanisms, but the intensity varies dramatically by agent. Quetiapine ranks between olanzapine (worst metabolic impact) and aripiprazole (lowest metabolic impact) for depletion severity. According to CTD data, quetiapine's 17 gene interactions target metabolically critical pathways despite the modest gene count, with its H1 binding affinity being the highest among its receptor targets. Olanzapine produces more severe weight gain and faster metabolic syndrome onset. Aripiprazole's unique partial D2 agonist mechanism avoids most metabolic complications, making it the preferred agent when nutrient depletion risk must be minimized. Risperidone's prominent prolactin elevation creates bone density concerns through a different pathway than the metabolic nutrient depletion that quetiapine drives.

[06]

Food Sources for Depleted Nutrients

Food	Amount per Serving
Beef heart	113 mg per 3.5oz (highest dietary source)
Sardines	6.4 mg per 3.5oz
Mackerel	4.3 mg per 3.5oz
Peanuts	2.7 mg per 3.5oz
Sesame seeds	2.3 mg per 3.5oz

Source: USDA Food Composition Database (658,209 food nutrient entries)

[07]

FAQ

[08]

References

[1]Comparative Toxicogenomics Database (CTD): 17 quetiapine gene interactions, 640 disease associations, 92 curated disease links (accessed April 2026)
[2]ChEMBL Database: Quetiapine classified as 5-HT2A antagonist with D2, H1, and alpha-1 receptor blockade, multi-receptor binding affinity data (accessed April 2026)
[3]FAERS Database: Adverse event reporting for quetiapine including metabolic syndrome, weight gain, hyperglycemia, dyslipidemia, and sedation-related events (accessed April 2026)
[4]PharmGKB Database: MC4R gene variant annotations for quetiapine-induced weight gain susceptibility (accessed April 2026)
[5]PubMed: 1,227 indexed articles for quetiapine covering metabolic effects, off-label prescribing patterns, mitochondrial dysfunction, and vitamin D deficiency (accessed April 2026)
[6]Kelda Health Intelligence Platform: Cross-referenced analysis integrating CTD, ChEMBL, FAERS, PharmGKB, and PubMed datasets including 114 RCTs across 165,412 patients (accessed April 2026)

This information is generated from peer-reviewed molecular databases including the Comparative Toxicogenomics Database (CTD), ChEMBL, and indexed PubMed research. It is not medical advice. Always consult your healthcare provider before making changes to your medications or supplements. See our methodology →

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