Methylfolate (5-MTHF) vs L-Citrulline

Vitamin vs Amino Acid · evidence-backed comparison

Quick take
  • Methylfolate (5-MTHF) has the stronger evidence base (strong (multiple rcts / meta-analyses)).
  • L-Citrulline has the broader effect profile across the 9 effect categories.
  • Methylfolate (5-MTHF) is cheaper per serving ($0.22 vs $0.65).
  • L-Citrulline has a slightly cleaner safety profile.

Side-by-side traits

TraitMethylfolate (5-MTHF)L-Citrulline
Category
VitaminAmino Acid
Active compound
L-5-methyltetrahydrofolateL-citrulline (or citrulline malate 2:1)
Form available
Capsule, TabletPowder, Capsule
Source
syntheticmicrobial
Typical dose
400–1000 mcg daily6–8 g pre-workout (citrulline malate 8 g)
Dose range
400–1000 mcg6–8 g
Loading protocol
Best taken with
with foodwater, empty stomach
Best time of day
morningpre-workout
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)Very High (5/5)
Onset time
Cumulative: 4–8 weeksAcute: 60 min
Half-life
~3 hours~1 hour
Evidence level
Quality and quantity of human research.
Strong (multiple RCTs / meta-analyses)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Low (2/5)Moderate (3/5)
Muscle / strength
Very Low (1/5)Moderate (3/5)
Physical energy
Moderate (3/5)High (4/5)
Focus / cognition
Moderate (3/5)Low (2/5)
Mood / stress
High (4/5)Low (2/5)
Sleep quality
Very Low (1/5)Very Low (1/5)
Immunity
Low (2/5)Very Low (1/5)
Recovery
Post-exercise recovery support.
Very Low (1/5)Moderate (3/5)
Longevity / healthspan
Moderate (3/5)Low (2/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
High (4/5)Very High (5/5)
Price per serving
Approximate USD per typical daily dose.
$0.22$0.65
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About Methylfolate (5-MTHF)

Pre-methylated folate that bypasses MTHFR variants. Essential during pregnancy and for treatment-resistant depression with low folate.

Active compound: L-5-methyltetrahydrofolate
Forms: Capsule, Tablet
Onset: Cumulative: 4–8 weeks
moodMTHFRpregnancyhomocysteine

About L-Citrulline

Pre-workout staple for vasodilation and reduced muscle soreness. Raises plasma arginine more efficiently than arginine itself.

Active compound: L-citrulline (or citrulline malate 2:1)
Forms: Powder, Capsule
Onset: Acute: 60 min
pumpendurancesorenessvasodilation

Methylfolate (5-MTHF) safety

Common side effects:

  • Anxiety / irritability (over-methylation)
  • Insomnia (PM use)

Avoid if:

  • Bipolar disorder

Drug interactions:

  • Methotrexate
  • Antiseizure meds

L-Citrulline safety

Common side effects:

  • Generally none

Avoid if:

  • Severe hypotension
  • Sildenafil interactions

Drug interactions:

  • Sildenafil
  • Blood pressure meds

Common uses

  • Pregnancy
  • MTHFR variants
  • Depression
  • Homocysteine

Stacks well with: Vitamin B12 (Methylcobalamin), Betaine Anhydrous

Common uses

  • Pre-workout pump
  • Endurance
  • Reduced DOMS

Stacks well with: Beta-Alanine, Creatine Monohydrate, Caffeine

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.