Study was terminated by the IRB due to continued noncompliance.

The purpose of this study is to determine the tolerability of L-Serine oral doses for ALS patients and assess preliminary indications of efficacy

All patients will receive the same dose of the study treatment over 6 months. For each participant the study will last approximately one year with follow up visits after the treatment period of 6 months is completed. The visits will include blood draws, vital sign checks, neurological and physical exams, pulmonary testing with forced vital capacity (FVC), and questionnaires.

Inclusion Criteria:

• Diagnosis of probable or definite ALS
• ALSFRS-R score >25 and FVC score ≥ 60% predicted
• If currently taking Riluzole and/or Edaravone/Radicava must be on stable dose for 3 months prior to Baseline/Screening. If the dosing has not been stable for 3 months prior to Baseline/Screening or if stopped due to an adverse event, the waiting period off the medication will be 7 days. If not on either of these medications may start if desired either or both medications after enrollment into study.

Exclusion Criteria:

• Diagnosis of probable or definite ALS more than 3 years prior to study enrollment
• Diagnosis or previous history of ischemic stroke, brain tumor, uncontrolled diabetes, renal insufficiency, or severe hypertension.
• Diagnosis or previous history of comorbid progressive neurodegenerative disease such as Alzheimer's disease, Parkinson's disease, Lewy Body disease, Pick's disease, Huntington's disease, Progressive Supranuclear palsy. ALS patients diagnosed with frontotemporal dementia will not be excluded from this study.
• Diagnosis or previous history of symptomatic peripheral neuropathy. Patients with findings of peripheral neuropathy on electrodiagnostic tests only but no clinical symptoms at the time of enrollment are eligible.
• Undergoing any chemotherapy or radiation therapy for any cancer
• Any medical condition likely to interfere with the conduct of the trial or survival of the patient during this study period
• Pregnant women or women who are breast feeding
• Has taken L-Serine supplement within 30 days prior to start of study drug

Participants determined to be eligible at screening visit

The adverse event data was collected from baseline through when participants withdrew from study or up to 48 weeks.

Routine monitoring revealed major noncompliance that was not adequately addressed by the Sponsor-Investigator. Subsequently, the study was terminated by the Institutional Review Board (IRB). The IRB determined these deviations compromised the integrity of the data. Furthermore, the study data collected have been deemed unreliable due to issues related to the study's conduct.

Routine monitoring revealed major noncompliance that was not adequately addressed by the Sponsor-Investigator. Subsequently, the study was terminated by the Institutional Review Board (IRB). The IRB determined these deviations compromised the integrity of the data. Furthermore, the study data collected have been deemed unreliable due to issues related to the study's conduct.