TUESDAY, Dec. 23, 2025 (HealthDay News) -- For patients with progressive multiple sclerosis (MS), the antioxidant lipoic acid (LA) does not slow the decline in walking speed or have other clinical effects compared with placebo, according to a study published online Dec. 15 in Neurology.Rebecca I. Spain, M.D., from the VA Portland Health Care System in Oregon, and colleagues examined the effects of LA in progressive MS in a phase 2, 24-month randomized trial conducted from 2018 to 2023 in 10 U.S. sites and one Canadian site. Participants were block-randomized by site to receive 1,200 mg daily oral LA or placebo (54 and 61 participants, respectively).The researchers found that LA did not slow the reduction in walking speed (−0.39 feet/second versus −0.30 feet/second), nor were there differences in mobility, other clinical, or patient-reported outcomes compared with placebo. LA participants had stable whole-brain volume, while a trend toward a decrease was seen with placebo, even after accounting for increased total T2-weighted lesion volume, which was greater in the LA group. LA participants had stable deep gray matter volume, while a decrease was seen for placebo participants. More proteinuria and fewer suicidal ideation events were seen in the LA group than the placebo group."It didn't work clinically in progressive multiple sclerosis the way we hoped," Spain said in a statement. "However, the slowing of brain atrophy that we saw in MRI images suggests that we may yet be on the right track, especially if we can find a better way to deliver the beneficial effects of an antioxidant like lipoic acid."Several authors disclosed ties to the biopharmaceutical industry.Abstract/Full TextEditorial (subscription or payment may be required).Sign up for our weekly HealthDay newsletter