Outcomes

What quercetin actually does, by outcome

Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.

Outcome Effect size Evidence Dose Weeks Rank

Catch fewer colds and infections Likely strong benefit

Your immune barriers intercept more viruses before they take hold.

1 RCT n=120 250 mg 12 wk #3/17

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1 RCT n=120

250 mg

12 wk

#3 /17

Improve insulin sensitivity Large effect, needs confirmation

Your cells respond to insulin again so your pancreas works less hard.

2 RCTs n=106 1000 mg 1–12 wk

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2 RCTs n=106

1000 mg

1–12 wk

—

Steady your blood sugar levels Large effect, needs confirmation

Keeps fasting glucose and your three-month average in a healthier range.

2 RCTs n=82 400–1000 mg 10–12 wk

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2 RCTs n=82

400–1000 mg

10–12 wk

—

Flatten post-meal blood sugar spikes Promising early signal

Blunts the glucose surge after eating so energy stays level.

1 RCT n=24 1000 mg 1 wk

35571883

moderate

1 RCT n=24

1000 mg

1 wk

—

Lower your blood pressure Proven modest benefit

Brings down both systolic and diastolic, especially when baseline runs high.

6 meta-analyses n=759 100–1000 mg 6–10 wk #3/81

19402938·21487493·24049596·24829713 +2 more

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6 meta-analyses n=759 Meta-analyzed

100–1000 mg

6–10 wk

#3 /81

Lower bad and total cholesterol Not enough research

Cuts the cholesterol that builds into artery plaque over time.

2 RCTs n=— 150–400 mg 6–10 wk

19402938·21487493

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2 RCTs n=—

150–400 mg

6–10 wk

—

Lower triglycerides Not enough research

Reduces the blood fats that rise after meals and drive heart risk.

1 RCT n=— 400 mg 10 wk

21487493

—

1 RCT n=—

400 mg

10 wk

—

Raise good cholesterol levels May have slight negative effect

Boosts the cholesterol that pulls fat out of artery walls.

2 RCTs n=278 150–400 mg 6–10 wk

19402938·21487493

small

2 RCTs n=278

150–400 mg

6–10 wk

—

Outcome	Effect	Evidence	Dose	Weeks	Rank
Catch fewer colds and infections Likely strong benefit	large	1 RCT n=120	250 mg	12 wk	#3/17
Improve insulin sensitivity Large effect, needs confirmation	large	2 RCTs n=106	1000 mg	1–12 wk	—
Steady your blood sugar levels Large effect, needs confirmation	large	2 RCTs n=82	400–1000 mg	10–12 wk	—
Flatten post-meal blood sugar spikes Promising early signal	moderate	1 RCT n=24	1000 mg	1 wk	—
Lower your blood pressure Proven modest benefit	small	6 meta-analyses n=759 Meta-analyzed	100–1000 mg	6–10 wk	#3/81
Lower bad and total cholesterol Not enough research		2 RCTs n=—	150–400 mg	6–10 wk	—
Lower triglycerides Not enough research		1 RCT n=—	400 mg	10 wk	—
Raise good cholesterol levels May have slight negative effect	small	2 RCTs n=278	150–400 mg	6–10 wk	—

Buy well

Recommended Quercetin products

Real products that dose Quercetin where the research does, in a clean formulation, from brands we've audited. We only list ones we'd stand behind.

Chosen for adequate Quercetin dosing vs. the studied range, a clean formulation (grade A–C), and independent brand-quality audits. Not sponsored.

Risk profile

Adverse events and known drug interactions

Safety events

treatment-related_carcinogenic_lesions (kidney, urinary bladder, intestine) in male rats severe

anaphylaxis severe

pneumonia severe

gastroenteritis severe

urinary_tract_infection severe

pro-oxidant effects in glutathione-depleted states; metabolic interactions affecting estrogen metabolism moderate

No serious adverse events reported in included RCTs; minor side-effects (headache, nausea, tingling) noted in other long-term reports mild

gastro-oesophageal reflux disease mild

Drug interactions

Tacrolimus major increases concentration

Carbamazepine major increases concentration

Antidepressants major increases concentration

Antipsychotics major increases concentration

Selexipag major increases concentration

Diclofenac major increases concentration

Warfarin major increases concentration

Quetiapine major increases concentration

Tucatinib major increases concentration

Cyclosporine moderate increases concentration

Co-studied with

Supplements that share evidence with quercetin

Sources

Generated August 14, 2026

Quercetin

What quercetin actually does, by outcome

Recommended Quercetin products

Adverse events and known drug interactions

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NewArginine

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NewCaffeine

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Arginine

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