Outcomes

What dha 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

Raise omega-3 levels Proven strong benefit

EPA and DHA build up in blood and cell membranes where they work.

7 RCTs n=482 1250–3276 mg 9–52 wk #1/6

23010452·23817470·24077434·30866834 +3 more

large

7 RCTs n=482

1250–3276 mg

9–52 wk

#1 /6

Build nutrient stores in pregnancy Likely strong benefit

Tops up the reserves pregnancy drains fastest.

1 RCT n=238 300–600 mg — #2/4

26413500

large

1 RCT n=238

300–600 mg

—

#2 /4

Improve school results in children Likely benefit

Better reading scores, sharper math, and fewer absences.

2 RCTs n=362 600–800 mg 16 wk

27188814·22970149

moderate

2 RCTs n=362

600–800 mg

16 wk

—

Lower triglycerides Likely modest benefit

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

2 RCTs n=316 1600–3000 mg 10–16 wk #1/89

23817470·36522805

small

2 RCTs n=316

1600–3000 mg

10–16 wk

#1 /89

Protect vision in retinal disease Faint early signal

Keeps sight sharper and retinal signals healthier when disease threatens.

2 meta-analyses n=60 600–3600 mg 208 wk #5/5

24805262·32573764

small

2 meta-analyses n=60 Meta-analyzed

600–3600 mg

208 wk

#5 /5

Boost overall cognitive performance Not enough research

Broad gains in memory, speed, and mental sharpness at once.

1 RCT n=60 1842 mg 52 wk #5/21

35373862

trivial

1 RCT n=60

1842 mg

52 wk

#5 /21

Protect against macular degeneration Probably doesn't help

Builds the protective pigment that shields your central vision from age.

1 meta-analysis n=— — — #1/6

41482231

large

1 meta-analysis n=— Meta-analyzed

—

#1 /6

Strengthen healthy birth weight Probably doesn't help

Babies who arrive at the right size face fewer risks at birth.

1 RCT n=238 600 mg — #6/7

26413500

trivial

1 RCT n=238

600 mg

—

#6 /7

Build thinking skills in children Not enough research

Stronger problem-solving, reasoning, and school performance as children grow.

2 RCTs n=— 800 mg —

25803546·27188814

—

2 RCTs n=—

800 mg

—

Outcome	Effect	Evidence	Dose	Weeks	Rank
Raise omega-3 levels Proven strong benefit	large	7 RCTs n=482	1250–3276 mg	9–52 wk	#1/6
Build nutrient stores in pregnancy Likely strong benefit	large	1 RCT n=238	300–600 mg	—	#2/4
Improve school results in children Likely benefit	moderate	2 RCTs n=362	600–800 mg	16 wk	—
Lower triglycerides Likely modest benefit	small	2 RCTs n=316	1600–3000 mg	10–16 wk	#1/89
Protect vision in retinal disease Faint early signal	small	2 meta-analyses n=60 Meta-analyzed	600–3600 mg	208 wk	#5/5
Boost overall cognitive performance Not enough research	trivial	1 RCT n=60	1842 mg	52 wk	#5/21
Protect against macular degeneration Probably doesn't help	large	1 meta-analysis n=— Meta-analyzed	—	—	#1/6
Strengthen healthy birth weight Probably doesn't help	trivial	1 RCT n=238	600 mg	—	#6/7
Build thinking skills in children Not enough research		2 RCTs n=—	800 mg	—	—

Buy well

Recommended DHA products

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

Chosen for adequate DHA 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

gastrointestinal discomfort

headache

tenesmus

weight gain

sedation

extrapyramidal symptoms

any adverse event (increased overall)

adverse events (any)

Sources

Generated August 14, 2026

DHA

What dha actually does, by outcome

Recommended DHA products

Adverse events and known drug interactions

More evidence for DHA

Borrowed Light: How a Sea Molecule Quietly Rewrote the First Chapters of Human Life

Focus & memory: evidence map across 45 supplements

Stress: evidence map across 46 supplements

Metabolic health: evidence map across 82 supplements

DHA

Recommended DHA products

More evidence for DHA

NewBorrowed Light: How a Sea Molecule Quietly Rewrote the First Chapters of Human Life

NewFocus & memory: evidence map across 45 supplements

NewStress: evidence map across 46 supplements

NewMetabolic health: evidence map across 82 supplements

Borrowed Light: How a Sea Molecule Quietly Rewrote the First Chapters of Human Life

Focus & memory: evidence map across 45 supplements

Stress: evidence map across 46 supplements

Metabolic health: evidence map across 82 supplements