Rosemary

Best for

Sharpen focus and mental stamina

Faint early signal · 200–1000 mg/day for 4 weeks · 2 studies , n=97

5 papers · 2 claims · 19 outcomes scored · 2 positive

Outcomes

What rosemary 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

Sharpen focus and mental stamina Faint early signal

Concentrate longer, resist distraction, and stay mentally sharp through demanding tasks.

2 RCTs n=97 200–1000 mg 4 wk

41312013·33233510

small

2 RCTs n=97

200–1000 mg

4 wk

—

Speed up thinking and reactions Barely detectable

Shortens the gap between seeing a question and having the answer.

1 RCT n=21 1000 mg 4 wk

33233510

trivial

1 RCT n=21

1000 mg

4 wk

—

Outcome	Effect	Evidence	Dose	Weeks	Rank
Sharpen focus and mental stamina Faint early signal	small	2 RCTs n=97	200–1000 mg	4 wk	—
Speed up thinking and reactions Barely detectable	trivial	1 RCT n=21	1000 mg	4 wk	—

Risk profile

Adverse events and known drug interactions

Safety events

scalp itching / local irritation mild

gastrointestinal discomfort mild

nausea mild

increased stool frequency / abdominal cramps mild

scalp burning and itching

Drug interactions

Fluoxetine minor additive

Sources

Generated August 14, 2026

Rosemary

What rosemary actually does, by outcome

Adverse events and known drug interactions

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