Evening Primrose

Best for

Reduce hot flashes and night sweats

Likely strong benefit · 1000–2000 mg/day for 8 weeks · 1 meta-analysis , n=613

15 papers · 4 claims · 37 outcomes scored · 4 positive

Outcomes

What evening primrose 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

Reduce hot flashes and night sweats Likely strong benefit

Fewer episodes and milder flushes, especially overnight.

2 meta-analyses n=613 1000–2000 mg 8 wk #1/3

33942584·41883983

large

2 meta-analyses n=613 Meta-analyzed I²=84%

1000–2000 mg

8 wk

#1 /3

Ease the full menopause symptom load Promising early signal

Less joint pain, fewer palpitations, and cooler nights.

1 RCT n=82 1000–2000 mg 8 wk #3/13

37694196

moderate

1 RCT n=82

1000–2000 mg

8 wk

#3 /13

Ease cyclical breast tenderness Likely modest benefit

Hormonal soreness fades so you stop dreading each cycle.

1 meta-analysis n=— 1000–4000 mg — #2/4

36446563

small

1 meta-analysis n=— Meta-analyzed

1000–4000 mg

—

#2 /4

Ease eczema flares Likely real but unnoticeable

Less redness, fewer outbreaks, and reduced need for steroid creams.

2 meta-analyses n=339 160–3600 mg 8–16 wk #3/6

23633319·30065580

trivial

2 meta-analyses n=339 Meta-analyzed

160–3600 mg

8–16 wk

#3 /6

Outcome	Effect	Evidence	Dose	Weeks	Rank
Reduce hot flashes and night sweats Likely strong benefit	large	2 meta-analyses n=613 Meta-analyzed	1000–2000 mg	8 wk	#1/3
Ease the full menopause symptom load Promising early signal	moderate	1 RCT n=82	1000–2000 mg	8 wk	#3/13
Ease cyclical breast tenderness Likely modest benefit	small	1 meta-analysis n=— Meta-analyzed	1000–4000 mg	—	#2/4
Ease eczema flares Likely real but unnoticeable	trivial	2 meta-analyses n=339 Meta-analyzed	160–3600 mg	8–16 wk	#3/6

Buy well

Recommended Evening Primrose products

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

Chosen for adequate Evening Primrose 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

reports of inflammation, thrombosis, and immunosuppression after prolonged use (>1 year) (case report) severe

serious treatment-emergent adverse events (overall) severe

pancreatitis severe

Nausea, drowsiness, mild headache mild

chromaturia mild

increased bleeding (reported with concomitant warfarin)

xerotic cheilitis

nausea

Drug interactions

Lithium major decreases concentration

Antithrombotic Agents major increases toxicity

Tamoxifen moderate increases effect

Misoprostol moderate increases effect

Sources

Generated August 14, 2026

Evening Primrose

What evening primrose actually does, by outcome

Recommended Evening Primrose products

Adverse events and known drug interactions

More evidence for Evening Primrose

Ceramides

Probiotics

Aloe

Aloe vera

Collagen

Hyaluronic Acid

Evening Primrose

Recommended Evening Primrose products

More evidence for Evening Primrose

NewCeramides

NewProbiotics

NewAloe

NewAloe vera

NewCollagen

NewHyaluronic Acid

Ceramides

Probiotics

Aloe

Aloe vera

Collagen

Hyaluronic Acid