CDP-Choline (Citicoline) vs Glycine

Nootropic vs Sleep · evidence-backed comparison

Quick take
  • Glycine is cheaper per serving ($0.10 vs $0.90).
  • Glycine has higher bioavailability (better absorption).

Side-by-side traits

TraitCDP-Choline (Citicoline)Glycine
Category
NootropicSleep
Active compound
Cytidine diphosphate-cholineGlycine
Form available
Capsule, PowderPowder, Capsule
Source
syntheticsynthetic
Typical dose
250–500 mg daily3 g before bed
Dose range
250–500 mg3–5 g
Loading protocol
Best taken with
with foodwater, 30 min before bed
Best time of day
morningevening
Bioavailability
How efficiently the body absorbs and utilizes the compound.
High (4/5)Very High (5/5)
Onset time
Acute: 1–3 hoursAcute: 30–60 min
Half-life
~70 hours~1 hour
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Low (2/5)
Muscle / strength
Very Low (1/5)Low (2/5)
Physical energy
Low (2/5)Very Low (1/5)
Focus / cognition
High (4/5)Low (2/5)
Mood / stress
Moderate (3/5)Moderate (3/5)
Sleep quality
Very Low (1/5)High (4/5)
Immunity
Very Low (1/5)Very Low (1/5)
Recovery
Post-exercise recovery support.
Very Low (1/5)Low (2/5)
Longevity / healthspan
High (4/5)Moderate (3/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
Very High (5/5)Very High (5/5)
Price per serving
Approximate USD per typical daily dose.
$0.90$0.10
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About CDP-Choline (Citicoline)

Choline + cytidine — both crossing the blood-brain barrier to support membrane integrity, dopamine, and acetylcholine. Strong stroke-recovery evidence.

Active compound: Cytidine diphosphate-choline
Forms: Capsule, Powder
Onset: Acute: 1–3 hours
focusmemorystroke-recoverydopamine

About Glycine

Sweet-tasting amino that lowers core body temperature for deeper sleep. Cheap, well-tolerated, and especially useful with magnesium glycinate.

Active compound: Glycine
Forms: Powder, Capsule
Onset: Acute: 30–60 min
sleep-qualitydeep-sleepamino-acidthermal-regulation

CDP-Choline (Citicoline) safety

Common side effects:

  • Headache (rare)
  • GI upset

Avoid if:

  • Bipolar (mania)

Drug interactions:

  • Levodopa

Glycine safety

Common side effects:

  • Generally none

Avoid if:

  • Clozapine therapy

Drug interactions:

  • Clozapine

Common uses

  • Focus
  • Memory
  • Recovery from cognitive injury
  • ADHD

Stacks well with: Alpha-GPC, Caffeine

Common uses

  • Deep sleep
  • Sleep quality
  • Collagen synthesis

Stacks well with: Magnesium Glycinate, Melatonin

Medical disclaimer

SupplementDuel is for educational purposes only and is not medical advice. Consult a physician before starting, stopping, or combining supplements — especially if you are pregnant, breastfeeding, take prescription medication, or have a chronic condition.