What clinical trials are underway testing L‑serine for Alzheimer’s disease?
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Executive summary
Two registered, investigator-led clinical programs are testing oral L‑serine in people with neurodegenerative disease: an ongoing Phase II randomized trial of L‑serine in early-stage Alzheimer’s disease (registered as NCT03062449) and related Phase II work at Dartmouth/ Hanover that uses a 30 g/day dosing regimen; earlier Phase I safety work in ALS patients established tolerability at high daily doses and motivated the Alzheimer’s studies [1] [2] [3] [4].
1. What trials are underway: the registered Phase II in early Alzheimer’s
The clearest public record is a Phase II randomized, double‑blind, placebo‑controlled study testing L‑serine in early‑stage Alzheimer’s disease, registered on ClinicalTrials.gov as NCT03062449 and described in summaries of ongoing research [1] [2]. Alzheimer’s Drug Discovery Foundation materials and other overviews explicitly identify this Phase II study as the active Alzheimer’s trial evaluating L‑serine’s effects on cognitive decline [2] [5].
2. Dosage and investigators: 30 g/day, gummy formulation, Dartmouth investigators
Public reporting and trial summaries indicate the Alzheimer’s trial uses a total daily L‑serine dose of 30 grams, administered as 15 gummies twice daily (each gummy 1 g, packet of 15 pieces) produced under GMP conditions, and that investigators at Dartmouth-Hitchcock (Hanover, N.H.) are principal sites with clinicians such as Aleksandra Starck supervising Alzheimer’s patients [2] [3]. Media coverage and institutional outlets also identify Dartmouth investigators leading a Phase II Alzheimer’s study using the 30 g/day regimen [3].
3. The trial’s rationale and relation to prior human work
The Alzheimer’s Phase II was launched after preclinical signals in animal models and a Phase I safety trial in 20 ALS patients that reported tolerability of up to 30 g/day and exploratory hints of clinical benefit; those ALS data helped justify testing L‑serine in other neurodegenerative disorders including Alzheimer’s [4] [6] [7]. Investigators cite mechanistic studies—astrocyte serine synthesis deficits in AD mice and protective effects of supplementation in models—as part of the biological rationale for human testing [8] [6].
4. What the trials are designed to measure and their regulatory posture
Public descriptions state the Alzheimer’s Phase II is randomized and placebo‑controlled, using clinical outcomes and likely biomarker assessments consistent with AD trial norms; because Alzheimer’s trials must be registered, the ClinicalTrials.gov record provides the formal trial framework and eligibility/outcome fields [1] [9]. The Dartmouth program’s Phase II status places the work squarely in efficacy‑testing rather than early safety only [2] [3].
5. Safety signals, cautions, and competing interpretations
Not all researchers endorse serine supplementation: a UC San Diego lab reported increased PHGDH expression in Alzheimer’s brain tissue and warned that boosting serine might be unhelpful or harmful, prompting media caution even as trials proceed [10] [11]. Independent reviewers and foundations note that while phase I ALS work supports short‑term tolerability, no clinical studies have established safety of L‑serine supplementation in healthy adults and evidence for benefit in dementia remains weak pending Phase II results [4] [5] [2].
6. Hidden agendas, funding and the evidence gap
The trials are largely investigator‑driven and linked to nonprofit research networks (e.g., Brain Chemistry Labs/Institute for Ethnomedicine and Dartmouth investigators), which has powered both preclinical enthusiasm and the current clinical programs; some media coverage amplifies promising preclinical findings (monkey and vervet studies) that motivated the trials but can overstate translatability to humans [3] [12]. Crucially, public sources show that the Alzheimer’s Phase II is the primary active test of L‑serine for AD, and definitive efficacy and long‑term safety data are not yet available—ongoing trial results will determine whether supplementation is beneficial, neutral, or harmful [2] [1] [10].
Bottom line
A Phase II trial registered as NCT03062449 and investigator‑led Phase II work at Dartmouth testing 30 g/day L‑serine in early Alzheimer’s are the main clinical efforts currently underway; these studies build on prior high‑dose safety testing in ALS and preclinical signals, but definitive efficacy and population safety data are pending and contested by researchers who caution against routine supplementation until trial results are reported [1] [2] [4] [10].