Echinacea purpurea

Best for

Catch fewer colds and infections

Proven strong benefit for 2–23 weeks · 3 studies , n=882

9 papers · 4 claims · 24 outcomes scored · 4 positive

Outcomes

What echinacea purpurea 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 Proven strong benefit

Your immune barriers intercept more viruses before they take hold.

3 RCTs n=882 2.5–4000 mg 2–23 wk #4/17

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large

3 RCTs n=882

2.5–4000 mg

2–23 wk

#4 /17

Ease cold and flu severity Faint early signal

When you do get sick, the whole experience hits lighter.

4 RCTs n=206 2.5–4000 mL 1–16 wk

15156472·35559249·39702335·23024696

small

4 RCTs n=206

2.5–4000 mL

1–16 wk

—

Ease bronchitis symptoms Faint early signal

Shorten and lighten a bronchitis episode for you or your child.

2 RCTs n=86 2.5–15 mL 1–2 wk #1/2

15156472·39702335

small

2 RCTs n=86

2.5–15 mL

1–2 wk

#1 /2

Recover from colds faster Not enough research

Shaves days off a cold by clearing the virus sooner.

2 RCTs n=58 1200–16800 mg 1–16 wk #4/10

18450126·23024696

trivial

2 RCTs n=58

1200–16800 mg

1–16 wk

#4 /10

Outcome	Effect	Evidence	Dose	Weeks	Rank
Catch fewer colds and infections Proven strong benefit	large	3 RCTs n=882	2.5–4000 mg	2–23 wk	#4/17
Ease cold and flu severity Faint early signal	small	4 RCTs n=206	2.5–4000 mL	1–16 wk	—
Ease bronchitis symptoms Faint early signal	small	2 RCTs n=86	2.5–15 mL	1–2 wk	#1/2
Recover from colds faster Not enough research	trivial	2 RCTs n=58	1200–16800 mg	1–16 wk	#4/10

Buy well

Recommended Echinacea purpurea products

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

Chosen for adequate Echinacea purpurea 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

oral aphthous ulcer severe

serious adverse events (unrelated fractures) severe

anaphylaxis severe

mild adverse effects mild

sleeplessness

no significant side effects reported

Vomiting and non-urticarial rash

Any adverse event (AE)

Drug interactions

Ritonavir major decreases concentration

Indinavir major decreases concentration

Nevirapine major decreases concentration

Efavirenz major decreases concentration

Cyclosporine major decreases concentration

Theophylline major decreases concentration

Cyclosporine major decreases effect

Midazolam moderate decreases concentration

Cyclosporine moderate unknown

Caffeine moderate decreases concentration

Co-studied with

Supplements that share evidence with echinacea purpurea

Sources

Generated August 14, 2026

Echinacea purpurea

What echinacea purpurea actually does, by outcome

Recommended Echinacea purpurea products

Adverse events and known drug interactions

Supplements that share evidence with echinacea purpurea

More evidence for Echinacea purpurea

The 7 Supplements That Actually Help You Catch Fewer Colds

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Echinacea purpurea

Recommended Echinacea purpurea products

More evidence for Echinacea purpurea

NewThe 7 Supplements That Actually Help You Catch Fewer Colds

NewEchinacea angustifolia

NewPalmitoylethanolamide

NewEchinacea

NewEuropean Elder / Elderberry (Sambucus nigra)

NewVitamin C

The 7 Supplements That Actually Help You Catch Fewer Colds

Echinacea angustifolia

Palmitoylethanolamide

Echinacea

European Elder / Elderberry (Sambucus nigra)

Vitamin C