A randomized, double-blind, placebo-controlled phase 3 clinical trial in 410 patients with early Parkinson disease found that nicotinamide riboside did not improve clinical outcomes and was associated with worse outcomes than placebo after 52 weeks.
Source: Human randomized trial, 410 patients with early Parkinson disease. People were assigned at random to take it or not: the strongest single kind of study for showing cause and effect.
What was found
The trial found that nicotinamide riboside treatment for 52 weeks did not improve clinical outcomes in patients with early Parkinson disease. The primary outcome, the Movement Disorder Society Unified Parkinson Disease Rating Scale total score (MDS-UPDRS parts I-III), increased by 2.45 points with nicotinamide riboside and decreased by 0.27 points with placebo. This resulted in an adjusted mean difference of 2.72 points favoring placebo.
Of the five key secondary outcomes, four showed no significant difference. However, nonmotor symptom burden worsened more with nicotinamide riboside, with the Non-Motor Symptoms Scale score showing an adjusted mean difference of 4.22 points favoring placebo.
Serious adverse events occurred in 17 (8.3%) of 205 participants receiving nicotinamide riboside and 29 (14.1%) of 205 receiving placebo.
How it was done
This was a randomized, double-blind, placebo-controlled, phase 3 clinical trial conducted at 11 centers in Norway. It included 410 patients aged 35 years or older with Parkinson disease diagnosed within 2 years before enrollment. Participants had a Hoehn and Yahr disease stage less than 3, abnormal dopamine transporter scintigraphy findings, and stable dopaminergic treatment before enrollment.
Patients were randomized to receive oral nicotinamide riboside, 500 mg twice daily (206 participants), or matching placebo (204 participants) for 52 weeks.
The primary outcome measured was the change from baseline to week 52 in the Movement Disorder Society Unified Parkinson Disease Rating Scale total score. Key secondary outcomes included individual parts of the MDS-UPDRS, dopamine transporter single-photon emission computed tomography brain imaging findings, and the Non-Motor Symptoms Scale score.
What it does not show
This 52-week trial involved 410 participants and focused on early-stage Parkinson disease. The findings may not apply to other stages of the disease or to longer treatment durations.
Some authors reported receiving personal fees or grants from various pharmaceutical companies. Two authors also reported having patents for the use of nicotinamide riboside as a method for treating Parkinson disease, licensed to Niagen Bioscience.
Who was talking about it
- AllSci on the news (2026-10-12): AllSci reported that the NOPARK trial found nicotinamide riboside worsened outcomes versus placebo in early Parkinson disease. See the post
- MedPage Today on the news (2026-10-09): MedPage Today reported that a popular longevity supplement failed to meet its endpoint in a Parkinson's trial. See the post
- Medical Daily on the news (2026-10-15): Medical Daily reported that the NAD supplement nicotinamide riboside failed to slow early Parkinson's in a year-long trial of 410 patients. See the post
The source
This is news, reported from the source above. It is not medical advice and not a recommendation. Talk to your doctor or pharmacist before you change any medicine or supplement.