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APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-22). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1127 · Search date 2026-07-22 · Methodology v0.6

Saffron extract,
does it really help with Lowering intraocular pressure and inhibiting progression when added to existing eye-drop treatment for primary open-angle glaucoma?

30-Second Summary
C
Evidence Grade C · 40 · Safety caution
A small randomized placebo-controlled trial supports C with 40 points for a short-term pressure signal, while visual-field preservation, optic-nerve structure, and progression inhibition each remain ? because direct human evidence is absent
What the
research shows
The overall claim for adding saffron extract to glaucoma eye drops is rated C. A four-week pilot randomized placebo-controlled trial in 34 participants found a small positive signal with 30 mg per day: mean intraocular pressure at week 4 was 10.6 mmHg versus 13.8 mmHg. This supports C for short-term pressure lowering. However, pressure is a surrogate, each arm had only 17 participants, and only one specific aqueous extract was tested. There is no direct human evidence for this extract on visual-field preservation, optic-nerve structure, or inhibition of glaucoma progression, so each of those outcomes remains ?. The overall verdict is therefore C with 40 points, the bottom of the C band. Absence of adverse events in a short trial is not generalized to long-term safety or different products.
What the
ads claim
Marketing can expand a brief pressure-care signal into optic-nerve protection, preserved visual fields, or stopped glaucoma progression. The actual trial added one aqueous extract at 30 mg to two established eye drops for four weeks and did not test visual fields or long-term progression.
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Useful facts when choosing a product

  • The direct trial used a particular aqueous saffron extract at 30 mg per day, while commercial supplements can differ in crocin, crocetin, and safranal content and extraction method.
  • Participants continued timolol and dorzolamide, so the study does not support replacing established glaucoma treatment with saffron.
  • No adverse events were reported during the four-week trial, but 34 short-term observations cannot establish long-term safety or detect rare events.
  • Higher supplemental doses can cause gastrointestinal symptoms, and supplemental use during pregnancy should be avoided or discussed with a clinician. Glaucoma drops should never be stopped without medical guidance.
Gap Measurement · Verdict 1127 · C 40
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Jabbarpoor Bonyadi and colleagues randomized 34 stable patients with primary open-angle glaucoma who continued timolol and dorzolamide to aqueous saffron extract 30 mg per day or placebo. Baseline pressure was 12.9 versus 14.0 mmHg and week-four pressure was 10.6 versus 13.8 mmHg; the difference disappeared after a one-month washout. The trial used pressure as its main outcome and was not large or long enough to test progression or visual-field loss. A 2019 review of 33 nutritional-intervention studies found the glaucoma evidence inconclusive, and a 2022 review likewise judged most clinical findings for saffron and other candidate antioxidants inconclusive.

02

Why this is classified as C (40)

A 34-participant, four-week pilot randomized placebo-controlled trial found a small positive pressure signal versus placebo, providing direct human evidence. Because pressure is a surrogate and the evidence comes from 17 participants per arm, one extract, and very short exposure, the maximum verdict is C with 40 points, the bottom of the C band. Visual-field preservation, optic-nerve structure, and progression inhibition each remain ? because direct human evidence for this extract is absent. Short-term tolerability does not establish long-term safety.

Counterpoint. Anyone choosing a supplement should tell the glaucoma specialist the product and dose while continuing the established eye-drop, laser, or surgical plan. Progression assessment requires repeated visual-field and optic-nerve or retinal nerve-fiber testing, not pressure alone.

Rejudgment record. Cross-check applied — Accepted the lower pressure versus placebo in the 34-participant, four-week pilot randomized trial as a small positive direct human signal. Surrogate-only measurement, 17 participants per arm, and testing of one extract cap the overall verdict at C with 40 points, the bottom of the band; visual-field preservation, optic-nerve structure, and progression inhibition each remain ? because direct human evidence for this extract is absent

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Short-term intraocular-pressure lowering as an adjunct to existing eye dropsCA positive 34-participant, four-week pilot signal exists, but it is a surrogate from one small trial of one extract.
Long-term inhibition of primary open-angle glaucoma progression?No direct human trial was found evaluating long-term visual-field or optic-nerve progression with saffron.
Prevention of glaucomatous visual-field loss?The only direct trial measured pressure only, leaving no efficacy literature on preservation of visual fields.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Jabbarpoor Bonyadi MH, Yazdani S, Saadat S. 2014Prospective comparative randomized placebo-controlled pilot intervention17Inadequately reported; academic-center studyFour-week intraocular pressure after add-on to timolol and dorzolamideWeek-four pressure was 10.6±3.0 versus 13.8±2.2 mmHg (p=0.001); the difference disappeared after washout and progression was not measured.Only direct small surrogate trial
Loskutova E et al. 2019Systematic review of nutritional interventions for glaucoma21Academic support from Dublin Institute of Technology; no proprietary interest reportedIntraocular pressure, ocular blood flow, visual-field, and progression-related outcomesTheoretical rationale and early signals existed, but evidence was inconclusive and higher-quality research was needed.Confirmation of evidence uncertainty
Chaudhry S et al. 2022Structured review of nutritional supplementation for glaucoma prevention and treatment11Academic review; limited product-specific independent clinical evidenceOxidative stress, intraocular pressure, and glaucoma-progression outcomesSaffron and other candidates warranted more research, while most clinical findings remained inconclusive.Later evidence-gap confirmation
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-22).

Jabbarpoor Bonyadi MH, Yazdani S, Saadat S. The ocular hypotensive effect of saffron extract in primary open angle glaucoma: a pilot study. BMC Complement Altern Med. 2014;14:399. PMID: 25319729. PMCID: PMC4213480. DOI: 10.1186/1472-6882-14-399.
checked
Loskutova E, O'Brien C, Loskutov I, Loughman J. Nutritional supplementation in the treatment of glaucoma: A systematic review. Surv Ophthalmol. 2019;64(2):195-216. PMID: 30296451. DOI: 10.1016/j.survophthal.2018.09.005.
checked
Chaudhry S, Dunn H, Carnt N, White A. Nutritional supplementation in the prevention and treatment of glaucoma. Surv Ophthalmol. 2022;67(4):1081-1098. PMID: 34896192. DOI: 10.1016/j.survophthal.2021.12.001.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-22 · Corrections: none

Cite this verdict

Saffron extract x intraocular-pressure reduction and progression inhibition in primary open-angle glaucoma Evidence Grade C card
[Chamgap] Saffron extract x intraocular-pressure reduction and progression inhibition in primary open-angle glaucoma — Evidence Grade C·40. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/eye/saffron-extract-primary-open-angle-glaucoma-pressure-progression/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.