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Goji

Goji

Best for

See more clearly

Faint early signal 25 g/day 13 weeks 1 study, n=114 #3 of 5 studied

Goji shows a faint early signal for visual acuity in healthy adults, but evidence remains too limited to support reliable benefits across broader eye, weight, metabolic, or performance outcomes.

Median effective dose, most-studied outcomes

  • Read fine detail more easily 25 g 13 wk
Full protocol, 1 outcomes

Risk, worst reported severity

  • hematuria/bleeding (elevated INR) moderate
  • intestinal gas mild
  • warfarin major
  • doxorubicin moderate
All 17 events and interactions

What goji actually does

Outcome Effect Evidence Dose Time Rank
Early research 1
See more clearly Faint early signal Clear vision helps a person read detail, recognize faces, and navigate everyday tasks.
small 		1 study 1 papers · n=114 25 g 13 wk #3 /5

Effect tiers come from native-unit MCID where available, Cohen's d otherwise.

Protocol

Dose, timing & forms

How much

The only consumer-facing outcome with a signal, visual acuity, used 25 g daily of goji berry for about 13 weeks in one small trial. 1 That result is early and small, so it does not justify chasing higher doses or expecting dramatic changes in reading, faces, or low-light detail.

When and how long

The useful practical takeaway is consistency, not a special time of day. The visual study used goji every day over roughly three months, rather than treating it as an as-needed vision booster. 1 Taking berries or a food-like preparation with a meal is a sensible way to fit it into a routine, but the trial does not establish that meal timing changes the result.

Forms & standardisation

The visual trial used goji berry itself, so dried fruit is closer to the available human evidence than a highly concentrated extract. 1 Labels often highlight zeaxanthin or polysaccharides, but no trial here establishes a target amount of either compound or shows that a standardized extract works better than the fruit.

Studied range, by outcome

Outcome Studied range Median effective Duration Evidence
Read fine detail more easily 25 g 25 g 13 wk 1 paper 1 sig. endpoint

Adverse events and drug interactions

Safety events

hematuria/bleeding (elevated INR) moderate
intestinal gas mild
hepatic steatosis
hepatic enzyme increased
hepatotoxicity
renal impairment
oxidative stress
splenomegaly

Drug interactions

warfarin major increases effect
warfarin major increases effect
warfarin major increases effect
doxorubicin moderate increases effect
dexamethasone moderate decreases concentration
neomycin moderate decreases effect
furosemide moderate decreases effect
isoniazid moderate decreases concentration
rifampicin moderate decreases concentration
Buy well

Recommended Goji products

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

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

In context

What this is and how it works

  • One randomized trial (n=114) reported improved visual acuity, but no noticeable-change threshold was established.1
  • Seven papers reviewed here span 36 outcomes, with only one early-tier claim.
  • Evidence comes from healthy adults, limiting conclusions for people with eye disease.

Goji is the dried red fruit of Lycium barbarum, a shrub long used in Asian foods and traditional preparations. You will see it sold as whole dried berries, juice, powder, or extracts, often marketed for eye health because the fruit supplies orange-red plant pigments.

Goji provides zeaxanthin, a yellow-orange pigment that concentrates in the macula, the tiny light-sensing spot at the back of your eye used for fine detail. Think of it as adding tint to a camera filter: it absorbs some high-energy light before that light reaches the sensor, though the one human trial does not establish that this process improves vision for most people. 1

Bottom line

Goji is reasonable for someone who enjoys the fruit and wants to test a food-based supplement with modest expectations about vision. The evidence is one small early trial, not a reliable case for broad eye, weight, metabolic, or performance benefits. Skip it if you take warfarin unless your prescribing clinician specifically clears it, and stop using it if you develop unusual symptoms.

Frequently asked

Common questions

Does goji berry improve eyesight?

One small randomized trial found an early signal for visual acuity after roughly 13 weeks of daily goji berry intake, but that is not enough evidence to promise sharper vision. 1

How long does goji berry take to work?

The visual-acuity trial ran for about 13 weeks, so goji is not an occasional, same-day supplement. 1

Can you take goji berry with warfarin?

No. Goji has a major interaction concern with warfarin because it can raise its blood-thinning effect. Speak with the clinician managing your medication before using it.

Sources

Sources

  1. 1. Double-masked, placebo-controlled, randomized trial of Lycium barbarum supplementation in healthy adults (2005) ↑

Generated August 27, 2026

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