L-Citrulline vs Selenium (Selenomethionine)
Amino Acid vs Mineral · evidence-backed comparison
- • L-Citrulline has the broader effect profile across the 9 effect categories.
- • Selenium (Selenomethionine) is cheaper per serving ($0.10 vs $0.65).
- • L-Citrulline has a slightly cleaner safety profile.
Side-by-side traits
| Trait | L-Citrulline | Selenium (Selenomethionine) |
|---|---|---|
Category | Amino Acid | Mineral |
Active compound | L-citrulline (or citrulline malate 2:1) | Selenomethionine |
Form available | Powder, Capsule | Capsule, Tablet |
Source | microbial | synthetic |
Typical dose | 6–8 g pre-workout (citrulline malate 8 g) | 100–200 mcg daily |
Dose range | 6–8 g | 100–200 mcg |
Loading protocol | — | — |
Best taken with | water, empty stomach | with food |
Best time of day | pre-workout | any |
Bioavailability How efficiently the body absorbs and utilizes the compound. | Very High (5/5) | Very High (5/5) |
Onset time | Acute: 60 min | Cumulative: 4–12 weeks |
Half-life | ~1 hour | ~252 days (long body store) |
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) | Low (2/5) |
Focus / cognition | Low (2/5) | Very Low (1/5) |
Mood / stress | Low (2/5) | Low (2/5) |
Sleep quality | Very Low (1/5) | Very Low (1/5) |
Immunity | Very Low (1/5) | Moderate (3/5) |
Recovery Post-exercise recovery support. | Moderate (3/5) | Low (2/5) |
Longevity / healthspan | Low (2/5) | Moderate (3/5) |
Safety rating 5 = exceptionally well-tolerated; 1 = significant risk profile. | Very High (5/5) | Moderate (3/5) |
Price per serving Approximate USD per typical daily dose. | $0.65 | $0.10 |
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 Selenium (Selenomethionine)
Cofactor for glutathione peroxidase and thyroid hormone activation. Two Brazil nuts per day already meet requirements; toxicity above 400 mcg.
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
Selenium (Selenomethionine) safety
Common side effects:
- • Selenosis (>400 mcg/day): hair loss, garlic breath, brittle nails
Avoid if:
- • Already eating Brazil nuts daily
Drug interactions:
- • Anticoagulants
Common uses
- • Pre-workout pump
- • Endurance
- • Reduced DOMS
Stacks well with: Beta-Alanine, Creatine Monohydrate, Caffeine
Common uses
- • Thyroid support
- • Hashimoto's
- • Antioxidant
Stacks well with: Iodine (Potassium Iodide)
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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.