Nicotinamide,
does it really help with Improved retinal ganglion-cell function and short-term visual function in glaucoma during intraocular-pressure-lowering treatment?
research showsHigh-dose oral nicotinamide is rated C because it has a short-term retinal-function signal in treated glaucoma. A 2020 crossover randomized trial in 57 participants reported improvement in the electroretinographic photopic negative response and some visual-field measures. A 2026 crossover trial in 53 participants with normal-tension glaucoma also improved electroretinographic amplitudes, but 12-week visual-field mean deviation, pattern standard deviation, and visual-field index did not differ from placebo. Phase 3 trials of long-term visual-field loss and blindness prevention remain ongoing, so the surrogate and short-term functional endpoint ceiling applies.
ads claimMarketing extends NAD metabolism and electroretinographic signals into optic-nerve regeneration, long-term field preservation, and blindness prevention. Completed monotherapy evidence remains limited to small 12-week crossover trials and functional measures.
Useful facts when choosing a product
- Nicotinamide is the amide form of vitamin B3 and is chemically distinct from nicotinic acid, the form commonly associated with flushing.
- Glaucoma trials have generally used 1 to 3 g per day, far above multivitamin amounts, while participants continued established intraocular-pressure-lowering treatment.
- High doses can cause nausea, vomiting, diarrhea, and liver-enzyme elevations, and drug-induced liver injury has been a concern at approximately 3 g per day.
- Completed short-term trials measured electroretinography and visual fields; they did not establish replacement of pressure-lowering therapy or prevention of blindness.
What the research actually shows
The double-masked crossover trial by Hui and colleagues compared 12 weeks of nicotinamide with placebo in 57 participants receiving glaucoma treatment. The photopic negative-response maximum amplitude improved with nicotinamide, and a signal was observed in the proportion with at least a 1-dB improvement in visual-field mean deviation. The phase 2 trial by De Moraes and colleagues found short-term improvement at visual-field locations in a 42-person nicotinamide-plus-pyruvate study, but the combination prevents attribution to nicotinamide alone. The 2026 crossover trial by Ha and colleagues replicated electroretinographic improvement but found no 12-week difference in visual-field indices. NAMinG and TGNT phase 3 trials of progression do not yet provide completed results.
Why this is classified as C (49)
Two small crossover trials observed electroretinographic retinal-function improvement, but short-term visual-field findings are mixed and no long-term field-loss or blindness-prevention result exists. Boundary rule ① for surrogate and short-term functional outcomes yields C with 49 points.
Counterpoint. Repeated electroretinographic improvement supports a biological signal, but a functional surrogate and a patient-important long-term endpoint are not equivalent.
Rejudgment record. New verdict — Accepted electroretinographic improvement in the small 2020 and 2026 crossover trials, but applied the boundary-rule ① ceiling of C because short-term visual-field findings are mixed and phase 3 evidence for long-term field loss or blindness prevention is unavailable
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) | Grade | Basis |
|---|---|---|
| Improved retinal ganglion-cell function | C | Two small crossover trials observed improvement in the electroretinographic photopic negative response. |
| Improved short-term visual function | C | Selected signals appeared in the 2020 monotherapy and phase 2 combination trials, but visual-field indices were null in the 2026 monotherapy trial. |
| Prevention of long-term visual-field loss | ? | No completed long-term phase 3 result is available. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Hui F et al. 2020 | Double-masked randomized placebo-controlled crossover trial | 57 | Academic and public-interest support including the Australian NHMRC and eye-research foundations | Electroretinographic photopic negative response and visual-field testing | Photopic negative-response maximum amplitude improved and selected mean-deviation responses showed a signal, but outcomes were short-term surrogates over 12 weeks. | Pivotal short-term monotherapy trial |
| Ha A et al. 2026 | Double-masked randomized placebo-controlled crossover trial | 53 | Academic support including the Korea Health Technology research program | Electroretinographic photopic negative response, B-wave, and 12-week visual-field indices | The photopic negative response and B-wave improved, but mean deviation, pattern standard deviation, and visual-field index did not differ significantly from placebo. | Replication for electroretinography with null visual-field indices |
| De Moraes CG et al. 2022 | Phase 2 randomized double-blind placebo-controlled trial | 32 | Academic and foundation support; combination supplementation | Short-term improvement at visual-field test locations | The nicotinamide-plus-pyruvate group improved selected short-term field measures, but mean deviation was not significant and the nicotinamide-only effect cannot be isolated. | Supportive combination evidence with attribution limits |
Receipt — 3 References
All 3 cited sources were verified for existence at the original page (as of 2026-07-23).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-23 · Corrections: none
Cite this verdict
[Chamgap] Nicotinamide x improved retinal ganglion-cell and short-term visual function in glaucoma — Evidence Grade C·49. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/eye/nicotinamide-glaucoma-retinal-ganglion-cell-visual-function/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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.