L-Serine
Also known as: Serine, L-Ser, 2-amino-3-hydroxypropanoic acid
Effective Dosage
No established dose for general use; disease-specific dosing used in clinical trials
What the Science Says
L-Serine is a naturally occurring amino acid found in the body and in many foods. It plays a role as a building block for proteins and as a precursor to D-serine, which helps regulate NMDA receptors in the brain. The strongest clinical evidence comes from small trials in children with rare genetic disorders (GRIN-related encephalopathies), where L-serine supplementation showed improvements in adaptive behavior, motor function, and quality of life over 12 months. Outside of these rare conditions, there is no established effective dose or proven benefit for healthy adults.
What It Doesn't Do
Not proven to boost brain performance in healthy people. No evidence it improves memory, focus, or mood in normal adults. Won't treat ALS or other neurodegenerative diseases based on these studies. Not a proven muscle-builder or fat-burner. The cancer cell research here is lab-based only — it does not mean L-serine treats cancer.
Evidence-Based Benefits
L-Serine is an amino acid that plays a crucial role in the synthesis of proteins and neurotransmitters. It has been studied for its potential benefits in cognitive function and neurological health, particularly in conditions like Alzheimer's disease and amyotrophic lateral sclerosis (ALS).
Moderate EvidenceEffective at: 500-2000 mg daily
Source: auto-research
Absorption & Bioavailability
Unknown from provided studies — oral absorption is assumed based on clinical use in pediatric trials, but no pharmacokinetic data was provided in the reviewed papers.
Red Flags to Watch For
- Evidence for benefit is almost entirely in children with rare genetic disorders (GRIN variants) — do not extrapolate to healthy adults
- Higher doses (≥5 mM in sperm studies) showed harm, suggesting dose-dependent toxicity risk
- Most papers provided are irrelevant to human supplementation (dairy cows, nanoparticles, subway air) — the ingredient is poorly studied for general consumer use
- One pediatric trial participant discontinued due to irritability and insomnia, indicating side effects are possible
- Over 1,000 supplement products contain L-serine (NIH DSLD), but clinical evidence for healthy adults is essentially absent
Products Containing L-Serine
See how L-Serine is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06