Magnesium Citrate vs NAC (N-Acetyl Cysteine)

Sleep vs Immune · evidence-backed comparison

Quick take
  • NAC (N-Acetyl Cysteine) has the stronger evidence base (strong (multiple rcts / meta-analyses)).
  • NAC (N-Acetyl Cysteine) has the broader effect profile across the 9 effect categories.
  • Magnesium Citrate is cheaper per serving ($0.12 vs $0.22).
  • Magnesium Citrate has higher bioavailability (better absorption).

Side-by-side traits

TraitMagnesium CitrateNAC (N-Acetyl Cysteine)
Category
SleepImmune
Active compound
Magnesium citrateN-acetyl L-cysteine
Form available
Capsule, Powder, Tablet, LiquidCapsule, Powder
Source
syntheticsynthetic
Typical dose
200–400 mg elemental Mg600–1800 mg daily
Dose range
200–400 mg600–1800 mg
Loading protocol
Best taken with
any time, with waterempty stomach or with food
Best time of day
anyany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
High (4/5)Moderate (3/5)
Onset time
Acute: 1–3 hoursAcute and cumulative
Half-life
~6 hours
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Strong (multiple RCTs / meta-analyses)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Moderate (3/5)
Muscle / strength
Low (2/5)Low (2/5)
Physical energy
Low (2/5)Low (2/5)
Focus / cognition
Very Low (1/5)Low (2/5)
Mood / stress
Low (2/5)Moderate (3/5)
Sleep quality
Moderate (3/5)Very Low (1/5)
Immunity
Very Low (1/5)High (4/5)
Recovery
Post-exercise recovery support.
Low (2/5)Moderate (3/5)
Longevity / healthspan
Moderate (3/5)High (4/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
High (4/5)High (4/5)
Price per serving
Approximate USD per typical daily dose.
$0.12$0.22
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About Magnesium Citrate

Most affordable absorbable magnesium. Doubles as a mild laxative — useful if constipated, less ideal if not.

Active compound: Magnesium citrate
Forms: Capsule, Powder, Tablet, Liquid
Onset: Acute: 1–3 hours
sleepconstipationvaluemuscle

About NAC (N-Acetyl Cysteine)

Glutathione precursor used clinically for liver protection (acetaminophen overdose). Strong evidence for OCD, COPD, and PCOS.

Active compound: N-acetyl L-cysteine
Forms: Capsule, Powder
Onset: Acute and cumulative
glutathioneliverlungOCD

Magnesium Citrate safety

Common side effects:

  • Loose stools (often desired)
  • GI cramps

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates

NAC (N-Acetyl Cysteine) safety

Common side effects:

  • Sulfur smell
  • GI upset
  • Headache

Avoid if:

  • Asthma (rare bronchospasm)

Drug interactions:

  • Nitroglycerin
  • Anticoagulants
  • Activated charcoal

Common uses

  • General magnesium repletion
  • Constipation
  • Sleep

Stacks well with: Vitamin D3

Common uses

  • Liver protection
  • Lung health
  • OCD / mental health
  • PCOS

Stacks well with: Vitamin C, Selenium (Selenomethionine)

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.