Magnesium L-Threonate (Magtein)

Name: Life Extension Magnesium L-Threonate (Magtein)
Brand: Life Extension
Price: 27.00 USD
Availability: InStock

Worth BuyingMagnesium-3 Hype

The only magnesium form demonstrated to cross the blood-brain barrier and elevate brain magnesium levels. Promising for cognitive function, but the evidence is still early-stage and it is expensive for the elemental magnesium you actually get.

80/ 100

Biorank Score

Independently ranked

80/ 100

Biorank Score

Independently ranked by Biorank Laboratories

Our Verdict

Worth Buying

Life Extension Magtein earns a strong formulation score because it uses the patented Magtein form with a legitimate mechanistic advantage. The 3-point hype penalty reflects the gap between the exciting mechanism (brain-penetrating magnesium) and the limited human clinical evidence — most promotional content overstates one small RCT. The low value score reflects the high price relative to elemental magnesium delivered.

Key Findings

Only magnesium form shown to cross the blood-brain barrier and raise CSF magnesium levels
One human RCT (Liu et al., 2016, n=44) showed cognitive improvement equivalent to ~9 years of brain age reversal
3-point hype penalty: exciting mechanism but limited human evidence (one small, industry-funded trial)
Delivers only 144mg elemental magnesium — not a replacement for general magnesium supplementation
At $0.90/serving, this is a premium play for brain-specific magnesium delivery

Evidence Analysis

Magnesium L-threonate (Magtein) was developed at MIT by Bhatt et al. (2010) and is the only magnesium form shown to significantly increase cerebrospinal fluid magnesium in animal models. Bhatt & Bhatt (2010, Neuron) demonstrated enhanced synaptic plasticity and memory in aged rats. A human RCT by Liu et al. (2016, Journal of Alzheimer's Disease, n=44) showed significant improvements in cognitive abilities equivalent to reversing brain age by ~9 years in subjects aged 50-70. However, human evidence remains limited to small trials funded by the patent holder (Magceutics/AIDP). Elemental magnesium content per dose is low (~144mg Mg from 2,000mg L-threonate).

Ingredient Breakdown

Ingredient	Dose	Effective Dose	Adequacy	Verdict
Magnesium L-Threonate (Magtein)	2000mg (144mg elemental Mg)	1500-2000mg		Optimal

True Cost Analysis

Properly Dosed -- What You Pay Is What You Get

Listed Price

$0.90/serving

$27.00/month at 1 serving/day

True Cost Per Effective Dose

$0.90/effective dose

$27.00/month for effective dosing

Value Score

Decent value

Save $19.50/month (72%)

by switching to NOW Foods Magnesium Glycinate

Where It Falls Short

Only one published human RCT (n=44), funded by the patent holder. Delivers only ~144mg elemental magnesium per dose — not sufficient to correct general magnesium deficiency. At $0.90/serving, it is 3-5x more expensive than other magnesium forms. Cannot replace glycinate or citrate for general magnesium supplementation. The cognitive claims are premature based on one small trial.