Comparative guide · 7 min read

Magnesium L-threonate vs citicoline — which actually helps cognition?

Updated 2026-05-20 · Reviewed by SupplementScore editors · No sponsorships

Two of the highest-claim cognition supplements, two completely different mechanisms, two very different prices. Magnesium L-threonate (Magtein) is patent-protected and pitched on a single small RCT showing improvements on a composite cognitive score in older adults. Citicoline (CDP-choline) has a much larger trial record in stroke recovery and age-associated memory complaints, plus a clearer mechanism of action. Both sit in our database at Tier 2, but the evidence quality and durability differ.

Quick verdict

GoalBetter choiceWhy
Age-associated memory complaints Citicoline Larger and more diverse trial base; consistent modest effect on memory and attention in adults 50+. Magtein has only one supporting RCT in this population.
Attention and processing speed (healthy adults) Citicoline The 2008 Spiers and 2012 McGlade trials in healthy women show small but reproducible improvements in attention. Magtein has no convincing trial in healthy young adults.
Sleep, anxiety, leg cramps L-threonate (only if magnesium-deficient) If a magnesium-replete patient is the use case, cheaper magnesium forms (glycinate, citrate) produce the same systemic effects at one-tenth the price.
Post-stroke or vascular cognitive recovery Citicoline Tens of trials, used clinically in parts of Europe and Latin America. Magtein has no stroke trial record.
Cost per effective dose Citicoline Roughly $0.30–0.60/day for 250–500 mg. Magtein runs $1.50–2.50/day for the 2 g trial dose.

How they compare on the things that matter

Mechanism — what they actually do

Magnesium L-threonate is a magnesium salt of L-threonic acid, developed at MIT in the early 2010s after animal work suggested it raised brain magnesium concentrations more effectively than other oral magnesium forms. The proposed mechanism is augmentation of NMDA-receptor-dependent synaptic plasticity — restoring magnesium's tonic block on NMDA receptors, which becomes desynchronised with age. Whether the human dose actually moves brain magnesium meaningfully remains a debated question; the supporting human pharmacokinetic data is thin and largely industry-funded.

Citicoline (cytidine 5′-diphosphocholine) is a precursor in the synthesis of phosphatidylcholine — a major component of neuronal membranes — and also a source of choline for acetylcholine production. Citicoline supplementation increases circulating choline and cytidine (which is converted to uridine in humans), both of which support membrane phospholipid synthesis. The pharmacology is reasonably well-characterised and the mechanism is plausible for both age-associated cognitive decline and acute neuronal injury (e.g. stroke).

Evidence base

Safety and side-effects

Magnesium L-threonate at the trial dose delivers roughly 144 mg of elemental magnesium daily — comfortably below the 350 mg/day tolerable upper limit for supplemental magnesium. GI side effects are uncommon at this dose because elemental magnesium is low. The form is well tolerated; the main downside is cost and the still-thin human safety database at multi-year exposures.

Citicoline has an excellent safety record across decades of European clinical use, with side effects (mild GI upset, headache) running at placebo rates in most trials. Doses up to 2 g/day have been used in stroke trials without notable adverse events. It does mildly raise plasma homocysteine in some patients via the methylation cycle; this is rarely clinically meaningful but is worth noting in patients with elevated homocysteine.

Practical rule. If the goal is cognition, citicoline has the deeper evidence base and the cheaper effective dose. Reserve magnesium L-threonate for patients who specifically value the magnesium-augmentation theory and can afford the premium, or who additionally want a (modest) systemic magnesium effect.

What the price difference buys you

The 2 g/day Magtein dose runs about $50–75/month at the patent holder's price points. Citicoline at the trial dose of 250–500 mg/day runs $10–18/month for generic or USP-grade product. Per dollar of measurable cognitive effect, citicoline is roughly 4–6× more cost-effective, and the gap is even wider when you account for the larger trial base.

Who should skip each

Magnesium L-threonate should be deprioritised in patients with significantly impaired renal function (eGFR < 30), where any magnesium loading can accumulate. People already taking another magnesium supplement at full dose should not stack the two.

Citicoline is best avoided in patients on cholinergic medications (donepezil, rivastigmine) without specialist supervision — the additive effect is rarely problematic but is worth flagging. Patients with high homocysteine or known methylation issues should monitor homocysteine if using citicoline chronically.

What we'd actually buy

For mild age-associated cognitive complaints in someone 50+: citicoline 250–500 mg/day, taken in the morning with food, as a 12-week trial. Combine with the rest of the evidence-based cognition foundation (omega-3 EPA/DHA, vitamin D to a normal 25-OH-D level, B12 if low, and resistance training plus aerobic exercise, which still outperform any supplement). If no perceived benefit at 12 weeks, stop — the effect is modest and not universal.

For magnesium-deficient adults who also want some cognitive benefit and can afford the premium: magnesium L-threonate at 1.5–2 g/day. Otherwise, magnesium glycinate at 300–400 mg elemental is the cheaper, more-evidenced choice for general magnesium repletion.

Sources

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