Taking magnesium L-threonate may benefit your cognitive, digestive, and mental health. Research is limited, but the evidence for these effects is promising.
- May Improve Your Memory
Magnesium L-threonate has shown promise for brain health.
What the Science Says: A 2022 study of 109 adults aged 18-65 found that magnesium L-threonate improved memory and cognition.
People who took 2 grams daily for 30 days showed better memory than those who took a placebo. Improvements were especially significant among older adults.
- May Help You Fall Asleep
Magnesium L-threonate has been shown to improve sleep and daytime functioning.
What the Science Says: In a 2024 study of 80 adults, researchers found that those who took magnesium L-threonate had improved deep and REM sleep compared to those who took a placebo. Participants also reported more daytime energy.
However, larger and longer studies are needed to confirm these benefits.
- May Ease Stress and Anxiety
Magnesium L-threonate has been shown to relieve stress and anxiety.
What the Science Says: In the 2024 study, participants who took magnesium L-threonate reported less stress and improved mood compared to the placebo group.
- May Decrease ADHD Symptoms
Attention-deficit/hyperactivity disorder (ADHD) is a condition that causes difficulties with attention, impulsiveness, and mood. Magnesium L-threonate supplementation may help manage ADHD.
What the Science Says: A 2021 clinical trial looked at 15 adults who took magnesium L-threonate supplements for up to 12 weeks. Almost half the group had significant improvements in ADHD symptoms.
Larger studies are needed to confirm this result.
- May Support Pain Relief
Magnesium L-threonate may help with pain relief. It may work by decreasing pain intensity in the brain.
What the Science Says: A 2023 study on people with cancer taking opioids found that participants taking 1.5-2 grams of magnesium L-threonate needed less morphine in 30-90 days than those on a placebo.
- May Help Relieve Constipation
Many types of magnesium promote digestive regularity. Magnesium is even included in some laxatives. Its salts draw water into the stool, which promotes gut motility and makes stool easier to pass.
What the Science Says: In the 2023 study of people with cancer, participants taking magnesium L-threonate had relief from opioid-induced constipation.
Which Foods Have Magnesium?
Many foods are rich in magnesium, including green leafy vegetables, legumes, whole grains, nuts, and seeds. Some breakfast cereals are fortified with magnesium.
Dietary sources of magnesium include:
- Pumpkin seeds, roasted: 156 milligrams (mg) per 1 ounce (oz) (37% DV)
- Chia seeds: 111 mg per 1 oz (26% DV)
- Almonds, dry roasted: 80 mg per 1 oz (19% DV)
- Spinach, boiled: 78 mg per ½ cup (19% DV)
- Cashews, dry roasted: 74 mg per 1 oz (18% DV)
- Peanuts, oil roasted: 63 mg per ¼ cup (15% DV)
- Soy milk: 61 mg per cup (15% DV)
- Black beans: 60 mg per ½ cup cooked (14% DV)
How Should You Take It?
Magnesium L-threonate supplements are typically sold as capsules or tablets, which you need to take with water. You can also find some magnesium L-threonate supplements in powder form.
Whether you should take magnesium L-threonate in capsule or powder form depends on your preference. Your body may absorb powder more quickly since it’s already dissolved. Your digestive system would need to break down a capsule.
One serving of most magnesium L-threonate supplements is multiple tablets. Most manufacturers recommend taking half of the dose in the morning and the rest in the evening.
Make sure to follow the dosage instructions given by the product manufacturer.
How Much Do You Need?
Your magnesium needs depend on age, sex, and whether you are pregnant.
Here are recommended dietary allowances (RDAs) and adequate intakes, measured in milligrams:
National Institutes of Health: Office of Dietary Supplements. Magnesium – health professional fact sheet.
Age Men Women Pregnant People Breastfeeding People
14-18 years 410 360 400 360
19-30 years 400 310 350 310
31 years and older 420 320 360 320
Is Magnesium L-Threonate Safe for Everyone?
People who have kidney disease may avoid magnesium supplements.
The kidneys remove excess magnesium from the body. Magnesium levels may rise to dangerous levels if the kidneys cannot function.
Potential Drug Interactions
Magnesium supplementation can decrease your body’s absorption of certain drugs. Other drugs can deplete magnesium stores.
Speak with a doctor before starting a magnesium supplement if you take:
- Antibiotics: Magnesium can decrease the absorption of certain antibiotics. Take antibiotics two hours before or 4-6 hours after magnesium.
- Biphosphonates: Magnesium can lower the absorption of osteoporosis drugs. Make sure to take them at least two hours apart.
- Diuretics: Water pills like Midamor (amiloride) can cause high magnesium levels. Loop and thiazide diuretics can increase urinary magnesium loss.
- Thyroid medications: Magnesium can lower thyroid hormone absorption and effectiveness. Separate them by at least four hours.
Can You Take Too Much?
Taking extremely high amounts of magnesium L-threonate may lead to magnesium toxicity, which can cause:
- Depression
- Hypotension (low blood pressure)
- Nausea or vomiting
- Urine retention
- Death
The FDA has established tolerable upper intake levels (ULs) for magnesium based on age. However, there are no ULs for infants aged 0-6 months. Your UL is the same as that of your general age group if you are pregnant.
The ULs include:
- 1-3 years: 65 mg
- 4-8 years: 110 mg
- 9-18 years: 350 mg
- 19 years and older: 350 mg
What Side Effects Should You Watch For?
The side effects of magnesium L-threonate are not well-known. Eating foods rich in magnesium usually does not cause harm, even in large amounts.
Magnesium supplements are generally safe. However, taking excess magnesium from dietary supplements could lead to side effects like:
- Abdominal (belly) cramps
- Diarrhea
- Nausea
