L-Citrulline vs Phosphatidylserine
Amino Acid vs Nootropic · evidence-backed comparison
- • L-Citrulline is cheaper per serving ($0.65 vs $0.80).
- • L-Citrulline has higher bioavailability (better absorption).
Side-by-side traits
| Trait | L-Citrulline | Phosphatidylserine |
|---|---|---|
Category | Amino Acid | Nootropic |
Active compound | L-citrulline (or citrulline malate 2:1) | Phosphatidylserine (sunflower-derived) |
Form available | Powder, Capsule | Capsule, Softgel |
Source | microbial | plant |
Typical dose | 6–8 g pre-workout (citrulline malate 8 g) | 100–300 mg daily |
Dose range | 6–8 g | 100–300 mg |
Loading protocol | — | — |
Best taken with | water, empty stomach | with food |
Best time of day | pre-workout | evening |
Bioavailability How efficiently the body absorbs and utilizes the compound. | Very High (5/5) | High (4/5) |
Onset time | Acute: 60 min | Cumulative: 3–8 weeks |
Half-life | ~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 | Moderate (3/5) | Very Low (1/5) |
Physical energy | High (4/5) | Very Low (1/5) |
Focus / cognition | Low (2/5) | Moderate (3/5) |
Mood / stress | Low (2/5) | 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. | Moderate (3/5) | Moderate (3/5) |
Longevity / healthspan | Low (2/5) | 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. | $0.65 | $0.80 |
Vegan friendly | Yes | Yes |
Gluten free | Yes | Yes |
3rd-party tested | Yes | Yes |
About L-Citrulline
Pre-workout staple for vasodilation and reduced muscle soreness. Raises plasma arginine more efficiently than arginine itself.
About Phosphatidylserine
Cell membrane phospholipid that lowers cortisol and supports memory in aging. Particularly useful for stress-induced poor sleep.
Vetted brands, third-party testing, ships worldwide.
Vetted brands, third-party testing, ships worldwide.
L-Citrulline safety
Common side effects:
- • Generally none
Avoid if:
- • Severe hypotension
- • Sildenafil interactions
Drug interactions:
- • Sildenafil
- • Blood pressure meds
Phosphatidylserine safety
Common side effects:
- • GI upset (high doses)
Avoid if:
- • Anticoagulants
Drug interactions:
- • Anticholinergics
- • Anticoagulants
Common uses
- • Pre-workout pump
- • Endurance
- • Reduced DOMS
Stacks well with: Beta-Alanine, Creatine Monohydrate, Caffeine
Common uses
- • Memory in aging
- • Cortisol management
- • Sleep
- • Athlete overtraining
Stacks well with: Fish Oil (Omega-3 EPA/DHA), Magnesium Glycinate
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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.