Your eye doctor says your glaucoma is stable on drops, but a relative sends you a video claiming that vitamin B3, sold as nicotinamide, can protect the optic nerve. Should you add it? The honest answer today is: not on your own. Small placebo-controlled trials have found short-term improvements in some measures of retinal function, but none has shown that nicotinamide slows glaucoma over years, the doses tested were far higher than in ordinary vitamins, and one trial participant developed liver injury. Larger trials are under way and are the thing to watch.
Why nicotinamide and NAD+ come up in glaucoma
Nicotinamide is a form of vitamin B3 that the body turns into NAD+, a molecule cells need to make energy. Glaucoma damages the retinal ganglion cells that carry signals from the eye to the brain, and lab research has suggested that these cells run short of energy as they age and come under pressure. That idea links glaucoma to the wider interest in NAD+ boosters such as NMN and nicotinamide riboside, which this site has covered for kidney disease and blood sugar.
Lowering eye pressure is still the only treatment proven to slow glaucoma. Nicotinamide is being studied as a possible add-on to that treatment, not a replacement for it.
What the small placebo-controlled trials found
In a crossover trial in Australia, 57 people already treated for glaucoma took nicotinamide or placebo for 12 weeks each. On electroretinography, a test of how well the inner retina responds to light, 23 percent improved beyond normal test variability on nicotinamide compared with 9 percent on placebo. Visual fields showed only a trend toward improvement.
A Korean crossover trial published in 2026 enrolled 53 people with normal-tension glaucoma, the type that progresses even though eye pressure is not high. Two electroretinography measures improved more on nicotinamide than on placebo, but there were no differences in visual field results after 12 weeks. One author holds a patent on nicotinamide treatment for glaucoma, which the paper discloses.
At Columbia University, a phase 2 trial randomized 42 people with moderate glaucoma damage to nicotinamide combined with pyruvate or to placebo; 32 completed about two months of treatment. More spots on the visual field test improved in the treatment group, though broader measures of overall field loss did not clearly change. A 2026 follow-up analysis of the same 32 eyes found the improvements clustered along typical glaucoma nerve-fiber pathways. Because pyruvate was given too, this trial cannot isolate what nicotinamide did alone.
NMN, another NAD+ precursor, has one small eye study. In a Japanese placebo-controlled trial of 14 older men with type 2 diabetes, retinal thickness in one region of the grid changed differently on NMN than on placebo over 24 weeks, and vision did not change in either group. Two authors listed affiliations with a nutraceutical company. That is an early measurement, not evidence of protection.
A 2026 systematic review of human studies concluded that the evidence is not enough to support routine high-dose nicotinamide in practice. Bigger answers should come from registered trials: the Glaucoma Nicotinamide Trial in Sweden, planned for about 660 people; the NAMinG phase 3 trial across UK eye centers, planned for about 496; and a 250-person nicotinamide and pyruvate trial in the United States.
A liver warning, and what to do today
The Columbia team also published a case report of drug-induced liver injury in a participant of a glaucoma neuroprotection trial, which they judged likely related to high-dose nicotinamide. They wrote the report partly because many patients already take nicotinamide as a supplement without medical supervision. The trial doses were measured in grams, many times the amount in a multivitamin, so a label that says vitamin B3 does not make the trial amounts harmless.
Keep using the pressure-lowering drops or treatment your eye doctor prescribed; no supplement trial has tested stopping them. If you are curious about nicotinamide, bring it up at your next eye appointment, mention any liver problems or other medicines, and ask whether one of the ongoing trials is recruiting near you. That route gets you supervision and blood tests rather than a guess.
The trials above used pharmaceutical-grade nicotinamide or NMN under study protocols. NAD+ or NMN listed by online research-chemical sellers is labeled for laboratory research only, not for human use, and none of those products was tested in these studies.
Sources
- Hui F et al. Improvement in inner retinal function in glaucoma with nicotinamide (vitamin B3) supplementation: a crossover randomized clinical trial. Clin Exp Ophthalmol, 2020 (PubMed)
- Ha A et al. Effects of nicotinamide supplementation in normal-tension glaucoma: a crossover placebo-controlled randomised clinical trial. Br J Ophthalmol, 2026 (PubMed)
- De Moraes CG et al. Nicotinamide and pyruvate for neuroenhancement in open-angle glaucoma: a phase 2 randomized clinical trial. JAMA Ophthalmol, 2022 (PubMed)
- De Moraes CG et al. Topographical analysis of visual field improvement in the phase 2 nicotinamide and pyruvate trial. Invest Ophthalmol Vis Sci, 2026 (PubMed)
- Shukla AG et al. Drug-induced liver injury during a glaucoma neuroprotection clinical trial. J Glaucoma, 2024 (PubMed)
- Shiraki A et al. Effect of nicotinamide mononucleotide on retinal thickness of older patients with diabetes mellitus. Geriatr Gerontol Int, 2026 (PubMed)
- Giudiceandrea A et al. Nicotinamide supplementation in glaucoma: a systematic review of human studies. Nutrients, 2026 (PubMed)
- ClinicalTrials.gov NCT05275738: The Glaucoma Nicotinamide Trial
- ClinicalTrials.gov NCT05405868: Nicotinamide in Glaucoma (NAMinG) phase 3 trial
- ClinicalTrials.gov NCT05695027: Nicotinamide and pyruvate for open-angle glaucoma
Related reading
- Semax for Glaucoma at Normal Eye Pressure: Two Thin Russian Reports
- Kidney Disease and NAD+ Supplements: What the Trials Have Shown
- Prediabetes and NAD+ Boosters: Did NMN or NR Lower Blood Sugar?
By The Everyday Brief. AI-assisted drafting with automated source and editorial checks. Sources fetched 2026-10-26 PT. Not medical advice.