Ashwagandha and Magnesium: Taking Both

Quick answer

The NIH fact sheets for ashwagandha and for magnesium do not name each other. One 2026 trial gave 600 mg of ashwagandha each morning and 145 mg of magnesium, as L-threonate, each evening, inside larger blends, so it cannot judge the pair. Ask first if you take thyroid medicine, which both can touch.^1,2,3

Key facts

Neither NIH fact sheet lists the other: the ashwagandha sheets name thyroid hormone, immune-suppressing and sedative medicines, and the magnesium sheets name antibiotics, bone medicines, diuretics and acid reducers.^2,3
The one trial that used both lasted two weeks in 103 adults and put other compounds in each blend, so it cannot say what ashwagandha or magnesium did on its own.¹
Magnesium from supplements has an adult upper limit of 350 mg a day. No upper limit has been set for ashwagandha, which NIH says appears well tolerated for about 3 months.^2,4
Both can upset the stomach and ashwagandha can cause drowsiness, so starting both on one day makes the cause of any problem hard to trace.^2,4
Thyroid medicine is where both come up: magnesium antacids can lower levothyroxine absorption, and ashwagandha may change thyroid hormone levels.^2,5

A herb and a mineral

Ashwagandha is the root of a shrub used in Ayurvedic medicine, sold mostly as a root extract that differs from maker to maker. Magnesium is a mineral the body needs every day. It comes from nuts, legumes and leafy greens, and it is sold as a supplement in several forms. That difference shapes the question: with a herb, the amount that was tested matters most, and with a mineral, what counts is the total from food and pills.^2,4

What each is graded for

Each ingredient file on this site grades its findings. These three sit closest to the reason people pair the two. Each carries its grade and the daily amount the studies used.

May support sleep quality*^2,6

Early evidence

A meta-analysis of five small trials (400 adults, all in India; four used one branded root extract) found a small improvement in sleep over placebo, larger at 600 mg a day and after 8 weeks or more. The effect was strongest in people with diagnosed sleep problems; for healthy adults the evidence comes from three small trials of that extract.

Amount studied: Mostly 600 mg a day of root extract, for 6 to 12 weeks

May modestly improve self-rated sleep in adults who sleep poorly*^7,8

Early evidence

One randomized, placebo-controlled trial tested this form: 155 adults who slept poorly took magnesium bisglycinate (250 mg of magnesium a day) or placebo for four weeks. Scores on a sleep-problem questionnaire fell a little more with magnesium (3.9 points against 2.3), a small effect, and other measures did not differ. It is a single short trial that relied on self-report. Older trials used other forms at higher doses in older adults and were rated low quality.

Amount studied: 250 mg a day as bisglycinate, 30 to 60 minutes before bed, for four weeks

As magnesium L-threonate, may modestly improve some measures of sleep and memory in adults who report poor sleep*^9,10

Early evidence

Two short placebo-controlled trials, both funded by companies that sell this form, tested it in adults who reported poor sleep. In 80 adults taking 1 g of the compound a day (about 75 mg of magnesium) for 21 days, the main sleep questionnaire improved about as much with placebo, while ring-measured deep and REM sleep scores and several daytime ratings came out better with the compound. In 100 adults taking 2 g a day (145 mg of magnesium) for six weeks, overall scores on a computer test of thinking and memory, and on one sleep questionnaire, came out better, while ring-measured sleep and most other sleep measures did not differ. No trial by researchers independent of the makers was found.

Amount studied: 1 to 2 g a day of magnesium L-threonate (about 75 to 145 mg of magnesium), for three to six weeks

There is no graded finding for the two together, because no trial gave just the pair. Anything said about the pair is an inference from separate findings, and this page reads it that way.

The one trial that gave both

A 2026 randomized trial gave 103 healthy, physically active adults a morning blend, an evening blend, both, or placebo for two weeks. The morning blend held 600 mg of ashwagandha and 300 mg of Rhodiola. The evening blend held 2 g of magnesium L-threonate, which supplies 145 mg of magnesium, with 200 mg of L-theanine and 50 mg of apigenin.¹

This is a report of what one trial measured, not a graded finding. The morning-only group showed lower weekly perceived stress, fewer sleep-related impairments, and less time awake after sleep onset on a wearable monitor. The group given both blends did not show more of that. On one sleep questionnaire the morning-only group scored better than the group given both. The authors read the result as a sign that the morning blend was behind the changes, and noted that effects may be small in healthy people over a short period.¹

Three limits apply. Each blend held compounds besides the two we care about. The supplements ran for two weeks. And every volunteer was healthy and active, so the result says little about anyone else.¹

Does one change how the body handles the other?

This is the question behind many searches for the pair, and the sources we use are silent on it. NIH's fact sheets on ashwagandha, written for health professionals and for consumers, do not mention magnesium. NIH's magnesium sheets do not mention ashwagandha. A PubMed search on October 7, 2026 found no study of either changing the absorption of the other.^2,3,4,11

Silence is not proof that nothing happens. It does mean that a claim about spacing the two apart for absorption has no source here. What the magnesium literature does document is that uptake depends on the amount, the form, a person's status and what else is in the meal, such as phytate, oxalate, some fibers and high doses of other minerals.¹²

Amounts and the upper limit

The two do not add up toward a shared limit, because ashwagandha supplies no magnesium. Magnesium's limit covers only magnesium from supplements and medicines, 350 mg a day for adults, and food does not count toward it. For ashwagandha there is only NIH's note that it appears well tolerated for about 3 months.^2,4

Daily amounts in the studies and on our labels^{2,4,7,9,10,13}
What	Amount	Where it comes from
Ashwagandha, most trials	600 mg of root extract, as two 300 mg doses	Trials NIH reviewed
Ashwagandha Complex	600 mg of a branded root extract per serving	Our label
Magnesium, recommended intake	310 to 320 mg for women and 400 to 420 mg for men, from all sources	NIH
Magnesium, sleep trial of the bisglycinate form	250 mg of magnesium	One four-week trial
Magnesium, L-threonate trials	1 to 2 g of the compound, about 75 to 145 mg of magnesium	Two company-funded trials
Magnesium Glycinate	275 mg of magnesium per serving	Our label

What’s in ours

Ashwagandha Complex: KSM-66 Ashwagandha Extract, 600 mg per serving, from the label

What’s in ours

Magnesium Glycinate: Magnesium, 275 mg per serving, from the label
Men's Multi: Magnesium, 50 mg per serving, from the label
Creatine + Electrolytes: Magnesium, 60 mg per serving, from the label

Our Ashwagandha Complex with our Magnesium Glycinate

Taken as their labels direct, their amounts do not overlap.

Magnesium also sits in Men's Multi at 50 mg and in Creatine + Electrolytes at 60 mg. With Magnesium Glycinate that comes to 385 mg of supplemental magnesium in a day, past the 350 mg figure, so anyone stacking those products should count the total.⁴

When the trials had people take them

No trial compared times of day for either ingredient, or compared taking the two at once with taking them apart. What exists is how each was dosed in its own trials.¹

Most trials split the daily amount into two 300 mg doses, and several told people to take each dose after food, with water or milk.^13,14,15,16

In the one trial of magnesium bisglycinate for sleep, people took their two capsules, 250 mg of magnesium in all, 30 to 60 minutes before bedtime.⁷

The share of magnesium the gut absorbs is higher when it is taken in several small amounts through the day than in one large amount.¹²

The pattern in the 2026 trial, ashwagandha in the morning and magnesium in the evening, was a design choice. The trial did not test it against any other schedule, so it is a description of what was done and not a finding about the best time.¹

Shared side effects, medicines and who should ask first

Both can upset the stomach. NIH lists upset stomach, loose stools, nausea and drowsiness for ashwagandha, and diarrhea, nausea and abdominal cramping for magnesium taken in high amounts from supplements. Starting both on the same day makes it hard to tell which one caused a problem.^2,4

Ask your pharmacist or doctor first

NIH says ashwagandha might interact with thyroid hormone medicines, such as levothyroxine. The concern comes from studies in which ashwagandha raised thyroid hormone levels, and from case reports of an overactive thyroid in people taking it.^2,11,17,18

Expected from how the two work, not shown in studies

Ask your pharmacist how far apart to take them

The levothyroxine label lists antacids, such as those made with aluminum and magnesium hydroxides, among products that may reduce levothyroxine absorption by lowering stomach acid. In a small 2025 study, magnesium aspartate taken at the same time lowered levothyroxine absorption by 12%, and magnesium citrate by 7%, a drop too small to rule out chance.^5,19,20

On the medicine's label

Both entries concern the same medicine by different routes. Magnesium antacids can lower how much levothyroxine the gut absorbs, and ashwagandha may shift thyroid hormone levels, so the dose a person needs could change. Ask a pharmacist how to arrange both alongside the medicine, and do not guess.^2,5

Rare cases of liver injury have been linked to ashwagandha, usually starting 2 to 12 weeks after people began taking it, with jaundice and itching. Most resolved within 1 to 4 months of stopping, but a few were fatal or needed a liver transplant, mainly in people who already had liver disease.^2,21

The risk of magnesium toxicity rises when the kidneys work poorly or have failed, because they cannot remove the excess.³

Ask first if you take levothyroxine or another thyroid medicine, or have a thyroid condition.^2,5
Ask first if you have liver disease, have had jaundice, or have had abnormal liver tests.²¹
Ask first if you have kidney disease or reduced kidney function.³
Ask first if you take sedatives, sleep medicines or anti-seizure medicines, because ashwagandha can add to drowsiness. Magnesium antacids also lowered gabapentin absorption in its label.^17,22
Do not take ashwagandha if you are pregnant or breastfeeding, and ask first if surgery is planned.¹⁷

Stop and see a doctor if you notice yellow skin or eyes, itching, dark urine, nausea or unusual tiredness. These can be signs of liver injury, which has been linked to ashwagandha.²¹

Questions people ask

Can I take magnesium glycinate and ashwagandha together?

No source we use documents a clash between them, and no trial tested the plain pair. That is a gap in the research, not a finding that the combination works better. If you take thyroid medicine or have liver or kidney problems, read the safety section first.^2,3

Can I take magnesium L-threonate and ashwagandha together?

The one trial that used both gave 2 g a day of magnesium L-threonate, about 145 mg of magnesium, in the evening and ashwagandha with Rhodiola in the morning. The L-threonate findings on this site are graded early, and both trials of it were funded by companies that sell it.^1,9,10

What is the best time to take ashwagandha and magnesium?

Nobody has tested it. Ashwagandha trials usually split 600 mg a day into two doses taken after food, and the one magnesium sleep trial had people take 250 mg of magnesium 30 to 60 minutes before bed.^7,13

Does ashwagandha change how much magnesium I need?

No source we use says so. Recommended magnesium amounts are set by age and sex, not by what else you take.⁴

Is magnesium a concern if my kidneys do not work well?

Yes, ask first. The kidneys remove extra magnesium, so the risk of magnesium toxicity rises when they work poorly or have failed.³

See what we make

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See the Full Measure line Ashwagandha Complex Creatine + Electrolytes Magnesium Glycinate

Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.