Magnesium L-Threonate and medications.
Magnesium L-Threonate is in the Distil supplement database, evidence Grade B. The page below lists every medication we have explicitly assessed it against.
Magnesium L-threonate is a magnesium form designed to raise magnesium specifically in the brain, using a threonate transporter that gives it better brain penetration than common forms like glycinate. That difference is the whole point: it is aimed at memory, synaptic density and cognitive ageing rather than general magnesium repletion. The evidence is Grade B, anchored by Slutsky's animal work on synaptic plasticity and a cognitive review by Zhang, so the case is promising rather than settled. The usual dose is 1,500 to 2,000mg of Magtein, which delivers only about 144mg of elemental magnesium, so it is not a substitute for a standard magnesium supplement. It is a distinct compound from magnesium glycinate and not interchangeable for cognitive goals; the two can be used together since they work differently. It is still elemental magnesium, so the same drug interactions apply as for any magnesium. It binds several medicines in the gut and reduces how much you absorb, and the spacing is not symmetrical: take an antibiotic such as ciprofloxacin or doxycycline at least two hours before, or six hours after, your magnesium. Levothyroxine wants a wider gap: take it first thing on an empty stomach and your magnesium at least four hours later, or at bedtime. Bisphosphonates, gabapentin and digoxin need separating too. In the other direction, long-term proton pump inhibitors or loop diuretics can lower your magnesium over time. It is expensive, which is worth weighing against the modest evidence. Some people get a headache when starting.
Below are the 14 documented pairs we have explicitly assessed for Magnesium L-Threonate: 14 amber. The pairs cluster around 3 mechanisms: Absorption interference, Mineral chelation (absorption), and Renal magnesium wasting (drug-induced). Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Last reviewed 14 June 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Absorption interference
Amber Does interact with Esomeprazole?
Long-term esomeprazole use is associated with low blood magnesium in about 1 in 5 chronic users. Magnesium L-threonate is still elemental magnesium, so supplementing is generally helpful, but if you have heart, kidney, or muscle symptoms on long-term esomeprazole, ask your GP for a magnesium blood test.
Evidence: Supported by human study data.
Amber Does interact with Lansoprazole?
Long-term lansoprazole use is associated with low blood magnesium in about 1 in 5 chronic users. Magnesium L-threonate is still elemental magnesium, so supplementing is generally helpful, but if you have heart, kidney, or muscle symptoms on long-term lansoprazole, ask your GP for a magnesium blood test.
Evidence: Supported by human study data.
Amber Does interact with Omeprazole?
Long-term omeprazole use is associated with low blood magnesium in about 1 in 5 chronic users. Magnesium L-threonate is still elemental magnesium, so supplementing is generally helpful, but if you have heart, kidney, or muscle symptoms on long-term omeprazole, ask your GP for a magnesium blood test.
Evidence: Supported by human study data.
Amber Does interact with Pantoprazole?
Long-term pantoprazole use is associated with low blood magnesium in about 1 in 5 chronic users. Magnesium L-threonate is still elemental magnesium, so supplementing is generally helpful, but if you have heart, kidney, or muscle symptoms on long-term pantoprazole, ask your GP for a magnesium blood test.
Evidence: Supported by human study data.
Mineral chelation (absorption)
Amber Does interact with Alendronic acid?
Magnesium binds to alendronic acid in the gut and blocks absorption, the same way calcium does. Magnesium L-threonate is still elemental magnesium, so it has the same effect. Take alendronic acid first thing on an empty stomach with plain water, stay upright for 30 minutes, then wait at least two hours before any magnesium supplement.
Evidence: Supported by human study data.
Amber Does interact with Ciprofloxacin?
Magnesium can bind to ciprofloxacin in the gut and sharply reduce how much antibiotic you absorb, which may let an infection persist. Take ciprofloxacin at least two hours before, or six hours after, any magnesium supplement.
Evidence: Supported by human study data.
Amber Does interact with Digoxin?
There are two things to know here, and on balance magnesium is more helpful than harmful. Taking magnesium at the same time as digoxin can slightly reduce how much digoxin you absorb, so it is sensible to separate them by about two hours. At the same time, a low magnesium level makes digoxin more likely to cause dangerous heart rhythms, so keeping your magnesium in the normal range is protective. Magnesium L-threonate is still elemental magnesium, so both points apply. Because digoxin has a narrow safe range, tell whoever prescribes it that you take magnesium.
Evidence: Supported by human study data.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does interact with Doxycycline?
Magnesium can bind to doxycycline in the gut and reduce how much antibiotic you absorb, which may let an infection persist. Take doxycycline at least two hours before, or six hours after, any magnesium supplement.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does interact with Gabapentin?
Taking magnesium at the same time as gabapentin can lower how much gabapentin your body absorbs, which may make it work less well. Magnesium L-threonate is still elemental magnesium, so the same effect applies. Take gabapentin at least two hours apart from any magnesium supplement, and keep the timing consistent day to day.
Evidence: Supported by human study data.
Amber Does interact with Levothyroxine?
Magnesium can bind levothyroxine in the gut and reduce how much you absorb, the same way calcium and iron do. Magnesium L-threonate is still elemental magnesium, so it carries the same binding effect. Take levothyroxine first thing on an empty stomach and take any magnesium supplement at least four hours later, or at bedtime.
Evidence: Limited human data, based on case reports and a known mechanism.
Amber Does interact with Minocycline?
Magnesium can bind to minocycline in the gut and reduce how much antibiotic you absorb. The effect is smaller than with older tetracyclines, but keep them apart: take minocycline at least 2 hours before or 6 hours after your magnesium.
Evidence: Limited human data, based on case reports and a known mechanism.
Amber Does interact with Risedronate sodium?
Magnesium binds to risedronate in the gut and blocks absorption. Magnesium L-threonate is still elemental magnesium, so it has the same effect. Take risedronate first thing on an empty stomach with plain water, stay upright for 30 minutes, then wait at least two hours before any magnesium supplement.
Evidence: Supported by human study data.
Renal magnesium wasting (drug-induced)
Amber Does interact with Bumetanide?
Bumetanide makes the kidneys pass out more magnesium in the urine, so people on it long term often run low on magnesium. This works the opposite way to most interactions: the medicine lowers your magnesium rather than the supplement affecting the medicine, so taking magnesium is generally a supportive response rather than a hazard. If you take bumetanide long term, especially for heart failure, it is worth asking your GP for a magnesium blood test and letting them know you supplement, since low magnesium can affect heart rhythm.
Evidence: Supported by human study data.
Amber Does interact with Furosemide?
Furosemide makes the kidneys pass out more magnesium in the urine, so people on it long term often run low on magnesium. This works the opposite way to most interactions: the medicine lowers your magnesium rather than the supplement affecting the medicine, so taking magnesium is generally a supportive response rather than a hazard. If you take furosemide long term, especially for heart failure, it is worth asking your GP for a magnesium blood test and letting them know you supplement, since low magnesium can affect heart rhythm.
Evidence: Supported by human study data.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
No affiliates. No commission. We earn nothing on what you buy.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologyA full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
£49 introductory price for early customers. Standard price £79.
Something missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.