tuneTypical Dose
2
Supplement
Sarcosine
N-methylglycine
Evidence TierCWADA NOT PROHIBITED
watchEffect Window
Usually 6-12 weeks.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Sarcosine is an amino acid neuromodulator that influences NMDA receptor signaling. It is used in research contexts for cognition and negative symptom support.
Small trials, largely in neuropsychiatric populations, suggest possible improvements in negative symptoms or cognitive measures when NMDA signaling is targeted. Evidence is inconsistent and not established for healthy users. Minority research explores effects on sleep architecture and neuroprotection in animal models. Headache, agitation, and interactions with psychiatric medications are possible.
Sarcosine increases NMDA-related neurotransmission via GlyT1 inhibition and may modulate schizophrenia symptom domains.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Possible reduction in schizophrenia symptom severity as add-on
- Best signal in chronic non-refractory subgroups
Secondary Outcomes
- Cognitive benefit inconsistent for sarcosine monotherapy add-on
- Combination NMDA-modulator protocols may show stronger cognitive signal
Safety
Contraindications and Interactions
Contraindications
- Unsupervised psychotic illness
- Replacement of prescribed antipsychotic treatment
- High-risk unstable psychiatric state without close follow-up
Side effects
- Generally mild short-term tolerability
- Possible GI discomfort/headache
- Uncertain long-term psychiatric safety profile
Interactions
- Antipsychotic regimen-dependent efficacy/safety
- Other NMDA/glutamatergic modulators
- Complex psychotropic polypharmacy
Avoid if
- No psychiatric supervision
- Pregnancy/lactation without specialist guidance
- Acute severe instability requiring urgent standard care
Evidence
Study-level References
sarcosine-SRC-001Systematic review and meta-analysis.
Sourceopen_in_newChang CH, et al. Efficacy and cognitive effect of sarcosine (N-methylglycine) in patients with schizophrenia: A systematic review and meta-analysis of double-blind randomised controlled trials. J Psychopharmacol. 2020;34(5):495-505. doi:10.1177/0269881120908016. PMID:32122256.
Population: 7 double-blind RCTs, 326 participants.
Dose protocol: Mostly adjunctive sarcosine regimens, typically 2 g/day.
Key findings: Overall symptom improvement signal. Cognition effect not statistically robust.
Notes: Heterogeneity and limited trial sizes.
Paper content
Overall symptom improvement signal; cognition effect not statistically robust.
sarcosine-SRC-002Systematic review and meta-analysis.
Sourceopen_in_newMarchi M, et al. Sarcosine as an add-on treatment to antipsychotic medication for people with schizophrenia: a systematic review and meta-analysis of randomized controlled trials. Expert Opin Drug Metab Toxicol. 2021;17(4):483-493. doi:10.1080/17425255.2021.1885648. PMID:33538213.
Population: 6 RCTs, 234 adults with schizophrenia.
Dose protocol: Oral sarcosine 2 g/day add-on in all trials.
Key findings: No significant overall pooled timepoint effect. Subgroup benefits in chronic/non-refractory schizophrenia.
Notes: Marked heterogeneity across timepoints and populations.
Paper content
No significant overall pooled timepoint effect; subgroup benefits in chronic/non-refractory schizophrenia.
sarcosine-SRC-003Multicenter randomized double-blind placebo-controlled trial.
Sourceopen_in_newLane HY, et al. Sarcosine or D-serine add-on treatment for acute exacerbation of schizophrenia: a randomized, double-blind, placebo-controlled study. Arch Gen Psychiatry. 2005;62(11):1196-1204. doi:10.1001/archpsyc.62.11.1196. PMID:16275807.
Population: 65 inpatients with acute exacerbation.
Dose protocol: Sarcosine 2 g/day or D-serine 2 g/day or placebo plus risperidone for 6 weeks.
Key findings: Sarcosine showed superior reductions in several PANSS/SANS domains.
Notes: Short-term trial. Comparator and co-therapy specific.
Paper content
Sarcosine showed superior reductions in several PANSS/SANS domains.
sarcosine-SRC-004Randomized double-blind dose comparison trial.
Sourceopen_in_newLane HY, et al. Sarcosine (N-methylglycine) treatment for acute schizophrenia: a randomized, double-blind study. Biol Psychiatry. 2008;63(1):9-12. doi:10.1016/j.biopsych.2007.04.038. PMID:17659263.
Population: 20 acutely symptomatic drug-free patients.
Dose protocol: 1 g/day vs 2 g/day sarcosine for 6 weeks.
Key findings: Higher response likelihood at 2 g/day. Both doses tolerated.
Notes: Small sample without placebo arm.
Paper content
Higher response likelihood at 2 g/day; both doses tolerated.
sarcosine-SRC-005Randomized double-blind placebo-controlled trial.
Sourceopen_in_newLin CY, et al. Adjunctive sarcosine plus benzoate improved cognitive function in chronic schizophrenia patients with constant clinical symptoms: A randomised, double-blind, placebo-controlled trial. World J Biol Psychiatry. 2017;18(5):357-368. doi:10.3109/15622975.2015.1117654. PMID:26691576.
Population: Chronic schizophrenia with stable clinical symptoms.
Dose protocol: Sarcosine 2 g/day + benzoate 1 g/day vs sarcosine 2 g/day over 12 weeks.
Key findings: Combination arm improved cognition/global functioning more than sarcosine alone.
Notes: Combination intervention limits single-agent attribution.
Paper content
Combination arm improved cognition/global functioning more than sarcosine alone.
sarcosine-SRC-006Network meta-analysis of randomized controlled trials.
Sourceopen_in_newLiang CW, Cheng HY, Tseng MCM. Augmentation with glutamatergic modulators for schizophrenia: A network meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry. 2025. doi:10.1016/j.pnpbp.2025.111495. PMID:40945815.
Population: 12,339 patients with schizophrenia across 148 randomized controlled trials.
Dose protocol: Network meta-analysis of 148 RCTs (n=12,339). Sarcosine 2000 mg/day as add-on to antipsychotics.
Key findings: Sarcosine 2000 mg/day showed greatest enhancement in global cognitive function (SMD 1.08) among glutamatergic modulators.
Notes: Largest comparative analysis placing sarcosine in context against other NMDA-pathway agents. Strengthens cognitive benefit signal.
Paper content
This network meta-analysis compared 12 glutamatergic modulators as adjuncts to antipsychotics across 148 RCTs and 12,339 patients with schizophrenia. D-serine at 2000 to 4000 mg/day demonstrated moderate to high certainty benefits in at least one symptom domain. Among all agents, piracetam showed the largest total psychopathology improvement (SMD -0.94), benzoate was strongest for positive symptoms (SMD -0.43), memantine for negative symptoms (SMD -0.64), and the sarcosine-benzoate combination for cognitive function. D-serine ranked below sarcosine and benzoate for most outcomes but remained a credible glutamatergic augmentation option. This is the largest network analysis placing D-serine in context against other NMDA-pathway modulators.