Get your free personalized podcast brief

We scan new podcasts and send you the top 5 insights daily.

Sleep is a brain process, yet popular forms of magnesium like oxide or citrate cannot cross the blood-brain barrier. Supplementation is only effective for individuals who are magnesium deficient. For others, it provides no direct sleep benefit and results in expensive urine.

Related Insights

The amount of melatonin in most over-the-counter supplements is significantly higher than what the body naturally produces. Because melatonin is a hormone, not just a sleep aid, taking these supraphysiological doses chronically can interfere with other critical hormone systems, including testosterone, estrogen, and those related to puberty in children.

Melatonin is not a sedative; it's a hormone that signals to your brain that it's nighttime. Meta-analyses show it only reduces the time to fall asleep by about 3-4 minutes. Its primary effective uses are for managing jet lag or specific circadian rhythm disorders.

The typical 5-gram dose of creatine primarily saturates the muscles, leaving little for the brain. Since some bioavailability is lost crossing the blood-brain barrier, higher doses (e.g., 20g) are required to achieve significant cognitive and neuroprotective benefits.

The standard 5g daily dose of creatine is mostly absorbed by muscles, especially in active individuals. To achieve cognitive benefits, a higher dose of 10g or more is necessary for the excess to cross the blood-brain barrier and support brain energy production.

Claims that creatine boosts brain function in healthy individuals are premature. Current scientific literature supports its cognitive benefits primarily in populations with existing deficits, such as those with traumatic brain injury, depression, or severe sleep deprivation, not the general public.

The popular advice to take magnesium for sleep is often flawed. Most common forms of magnesium (like oxide or citrate) do not cross the blood-brain barrier. Since sleep is a brain process, these supplements are unlikely to have a direct effect unless an individual is clinically deficient.

A natural and effective way to get magnesium for sleep is to make "banana tea." Cut a banana in half and boil it in water for about five minutes. The peel, which is rich in magnesium, leaches the mineral into the water, creating a potent, absorbable sleep aid.

The brain's glymphatic waste clearance system works best at night. Mark Burnett suggests taking his supplement in the evening and sleeping on an incline using a wedge pillow to physically assist this natural drainage process, potentially boosting the supplement's effects.

Standard glutathione supplements are largely a waste of money because the body lacks a transporter to get it inside cells. To be effective, the supplement must be in a "liposomal" form, which encapsulates the molecule so it can fuse with the cell and be utilized.

While 5g of creatine saturates muscles, the brain only sees significant benefits at higher doses of 10-25g. Muscles are "greedy" and absorb the lower amounts, so to overcome sleep deprivation or achieve cognitive enhancement, a much larger dose is needed for it to reach the brain.

Most Magnesium Supplements Don't Cross the Blood-Brain Barrier to Affect Sleep | RiffOn