A low-cost, naturally occurring compound related to glycine. Its strongest support is as an add-on for schizophrenia, easing low-motivation symptoms in stable patients, though results are inconsistent. Longevity interest rests on animal and cell studies only, with no human aging evidence. Generally well tolerated; long-term safety is untested. (Full Review)

Protocol

Standard Dose

2 g/day

Oral add-on; 500 mg–2 g/day for nootropic/longevity use

Best Time

Morning

Avoids sleep disruption from activating effect

Titration

Start ~500 mg

Build to 2 g over 1–2 weeks; once daily, splitting optional

Time to effect

Negative Symptoms

~6 weeks

Psychiatric trials assessed response at six weeks

Depression

~8 weeks

Add-on antidepressant response over eight weeks

Nootropic Effects

1–several weeks

Subtle onset over weeks, not immediate

Benefits

Medium: Reduction of negative symptoms in schizophrenia

Low: Improvement of overall and positive symptoms in schizophrenia; adjunctive relief of depressive symptoms

Speculative: Autophagy induction and calorie-restriction mimicry; muscle preservation and metabolic health; cognitive enhancement in healthy adults; reduction of obsessive-compulsive symptoms

Contraindications

Active or prior prostate cancer, or elevated PSA

Bipolar disorder or mania history

Pregnancy or breastfeeding

Significantly reduced kidney function

Key Interactions

Clozapine

NMDA-blocking agents (memantine, dextromethorphan, ketamine)

Other glycine-site agents (glycine, D-serine, D-cycloserine, D-alanine)

Stimulating supplements (high-dose creatine, nootropic stimulants)

Risk & Side Effects

Low: Gastrointestinal discomfort; overstimulation, insomnia, and irritability

Speculative: Theoretical promotion of prostate cancer growth; theoretical excitotoxicity from NMDA overactivation; unknown long-term safety

Monitoring

Marker	Target	Why
Prostate-specific antigen (PSA)	< 1.0 ng/mL (rising trend matters more)	Addresses theoretical prostate tumor-growth concern (men over ~40–50)
Serum glycine	Mid-to-upper reference range	Confirms sarcosine is raising glycine as expected
Kidney function (creatinine / eGFR)	eGFR > 90 mL/min/1.73m²	Sarcosine is cleared partly by the kidneys
Fasting glucose and lipids	Standard optimal metabolic ranges	General metabolic context for a longevity user

Cadence: Reassess symptoms and tolerability at ~2 and 6 weeks, then every 3–6 months; prostate (PSA) re-checks in men every 6–12 months

Qualitative Assessment

Motivation and drive
Mood and emotional engagement
Mental clarity, focus, and cognitive sharpness
Sleep quality (watching for overstimulation)
Social engagement and general sense of well-being

Sarcosine for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment