Phase I clinical trial of safety of L-serine for ALS patients

Amyotroph Lateral Scler Frontotemporal Degener. 2017 Feb;18(1-2):107-111. doi: 10.1080/21678421.2016.1221971. Epub 2016 Sep 2.


We performed a randomized, double-blind phase I clinical trial for six months on the effects of oral L-serine in patients with ALS. The protocol called for enrollment of patients with a diagnosis of probable or definite ALS, age 18-85 years, disease duration of less than three years and forced vital capacity (FVC) ≥ 60%. Patients were randomly assigned to four different oral twice-daily dose regimens (0.5, 2.5, 7.5, or 15 g/dose). Blood, urine and CSF samples, ALS Functional Rating Scale-Revised (ALSFRS-R) scores and forced vital capacity (FVC) were obtained throughout the trial. Disease progression was compared with matched historical placebo controls from five previous ALS therapeutic trials. Of 20 patients enrolled, one withdrew before receiving study drug and two withdrew with gastro-intestinal problems. Three patients died during the trial. L-serine was generally well tolerated by the patients and L-serine did not appear to accelerate functional decline of patients as measured by slope of their ALSFRS-R scores. Based on this small study, L-serine appears to be generally safe for patients with ALS.

Keywords: ALS; BMAA; L-serine; phase I; therapeutic trial.

Publication types

  • Clinical Trial, Phase I
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Amyotrophic Lateral Sclerosis / drug therapy*
  • Disease Progression
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Serine / therapeutic use*
  • Treatment Outcome
  • Vital Capacity / drug effects
  • Young Adult


  • Serine