Nicotinamide is a form of vitamin B3. Studies are looking into its potential to treat, protect and repair the optic nerve in people with glaucoma. Early research in both animals and humans has shown promising results. But high doses (far above the usual dietary amount) can sometimes cause side effects, including serious liver problems. Clinical trials are ongoing to better understand its safety and long-term benefits. This means it’s important not to self-medicate without medical advice.
The American Glaucoma Society (AGS) and American Academy of Ophthalmology (AAO) recommend the following guidelines for the use of nicotinamide in January 2025:
1. Nicotinamide is not approved for glaucoma and its safety is unknown.
If doses < 3 grams/day of nicotinamide are being considered by the patient or physician, collaboration with the primary care physician is necessary and periodic liver function testing should be performed.
2. High doses not recommended
Given the potential for drug-induced liver injury, the use of nicotinamide at high doses (≥ 3 grams/day) is not recommended outside the confines of clinical trials where liver function is closely monitored.
3. Possible side effects
Patients should be advised of possible side effects of nicotinamide and urged to report them immediately to their primary care physician or emergency room, depending on the severity of presentation. If enrolled in a clinical trial, patients with symptoms should also report them to the study investigators. Investigators and/or affected patients should provide these data to the Food and Drug Administration Safety Reporting Portal (https://www.safetyreporting.hhs.gov/).
4. Patients with prior liver disease
Patients with current or prior liver disease should not be offered nicotinamide supplementation.
5. Niacin vs nicotinamide
While niacin is a form of vitamin B3 and nicotinamide is its amide derivative, niacin and nicotinamide are not interchangeable.23 Niacin is not being tested as a neuroprotective agent in human glaucoma trials, and it is known to be hepatotoxic in high doses.28,29 Therefore, the AGS and Academy strongly recommend against the use of niacin in place of nicotinamide for glaucoma neuroprotection.
References:
- American Academy of Ophthalmology & American Glaucoma Society, Clinical statement, retrieved April 14, 2025, https://www.aao.org/education/clinical-statement/american-glaucoma-society-american-academy-of-opht
Want to learn more about the glaucoma research with Nicotinamide? Watch our patient seminar that mentions it here.