Most magnesium supplements never reach your brain. Magnesium oxide, citrate, and glycinate are well-absorbed into the bloodstream — but the brain has its own filter (the blood-brain barrier) that excludes most ionic magnesium.
Magnesium L-threonate is the form used in MIT research showing measurable increases in brain magnesium and improvements in sleep, focus, and short-term memory. It's the only magnesium form with peer-reviewed evidence of meaningful CNS uptake.
What to expect
- Crosses blood-brain barrier
- 2000mg per serving
- Magtein® form (clinical-trial grade)
How it works
How it works
Magnesium is a cofactor in 600+ enzymatic reactions, including the ones that regulate NMDA receptor activity, synaptic plasticity, and circadian sleep architecture.
When you take magnesium L-threonate:
- The L-threonate carrier (a vitamin C metabolite) shuttles magnesium across the blood-brain barrier, where most other forms can't pass
- Brain magnesium concentration measurably rises within 2-4 weeks
- The effect on NMDA receptor regulation is what underlies the sleep + focus signal in published trials
For peripheral effects (cramps, constipation, electrolyte balance), magnesium citrate or glycinate is equally good and cheaper. For brain-related goals, L-threonate is the only form with the evidence.
Why this formula
Why this formula
There is exactly one form of magnesium that has been shown to cross the blood-brain barrier in human trials, and it's the Magtein® form of magnesium L-threonate. Generic L-threonate from other suppliers does not have the same evidence base.
We use the patented Magtein® raw material at 2000mg per serving — the dose used in the original trials. No magnesium oxide or citrate cut in to lower per-bottle cost.
What happens next
- 1Complete your intake
Answer a few questions about your health history and treatment goals.
- 2Provider review
A licensed provider will review your information and create a personalized plan.
- 3Receive your treatment
Your prescription is sent to the pharmacy and shipped directly to you.
Frequently asked questions
Will this give me diarrhea like other magnesium forms?
Almost never. The L-threonate complex doesn't produce the osmotic effect that causes magnesium oxide or citrate loose stools. If you've avoided magnesium for that reason, L-threonate is the form to try.
Should I take this with food or before bed?
Most patients prefer 30-60 minutes before bed because of the sleep effect. It can be taken any time of day — absorption isn't food-dependent.
Do I still need a separate magnesium for cramps or constipation?
Possibly. L-threonate is optimized for brain delivery, not peripheral. If you take this for sleep/focus and still have peripheral magnesium deficiency symptoms (cramps, palpitations, constipation), adding a separate magnesium citrate or glycinate is reasonable.
How long until I notice anything?
Sleep effects often appear within the first week. Focus and short-term memory changes typically take 3-4 weeks. The original Magtein trials were 12 weeks long.
Is this safe long-term?
Magnesium L-threonate has been on the market since 2011 with no signal of long-term safety concerns in patients without kidney impairment. If you have CKD or are on potassium-sparing diuretics, discuss with your physician first.
Treatment overview
- Category
- General Care
- Type
- Supplement
- Available doses
- 2000mg
- Provider review
- Online review (no appointment needed)
- Fulfilled by
- PeakRx Compound Pharmacy
Ready to get started?
Complete your intake in just a few minutes. A licensed provider will review your information.
Start intake for Magnesium L-Threonate