Magnesium and Ashwagandha: What the Evidence Says About Stress

A significant share of the adult population does not reach the recommended daily intake of magnesium through diet. At the same time, chronic stress is an increasingly common experience. This is no coincidence: magnesium and stress are more closely connected than they may seem.

Magnesium is the fourth most abundant mineral in the human body and takes part in more than 300 enzymatic reactions. Ashwagandha (Withania somnifera) is an adaptogenic plant with over 3,000 years of use in Ayurvedic medicine. Individually, both have been the subject of scientific research in relation to stress and the nervous system. Magnesium holds EFSA-approved claims in this area; ashwagandha is accumulating a growing body of clinical evidence, although it has no authorised claims in the EU as of the date of this article. Together, their combination is generating increasing interest among researchers and health professionals.

This article looks at what we do know—and what we still don't—about taking magnesium and ashwagandha together for stress: mechanisms of action, available clinical evidence, available forms, studied doses, safety and contraindications. All of it grounded in studies published in peer-reviewed journals.

What magnesium is and why it matters for stress

Magnesium is an essential mineral that the body cannot synthesise: it has to be obtained through diet or a food supplement. It acts as a cofactor in more than 300 enzymatic reactions, including the synthesis of ATP (the cell's main energy currency), the regulation of the nervous system and the modulation of the hypothalamic-pituitary-adrenal (HPA) axis, the body's central stress-response system.

The link between magnesium and stress is bidirectional. Acute and chronic stress increase the urinary excretion of magnesium, which can lower its plasma levels. In turn, a magnesium deficit amplifies the stress response, creating a self-reinforcing cycle (Pickering et al., 2020).

From a neurochemical standpoint, magnesium acts as a natural antagonist of the NMDA (N-methyl-D-aspartate) receptor, a glutamate receptor involved in neuronal excitability. When magnesium levels are low, this blockade is reduced, which can increase excitatory activity in the central nervous system and contribute to states of anxiety and overactivation (Boyle et al., 2017).

A systematic review published in Nutrients (Boyle et al., 2017), which analysed 18 studies, found that magnesium supplementation was associated with a reduction in subjective anxiety, especially in people with low magnesium levels at the start of the study. The authors pointed to the need for clinical trials with greater methodological rigour.

The European Food Safety Authority (EFSA) has approved the claim that magnesium contributes to the normal functioning of the nervous system^* and contributes to normal psychological function^* (EFSA, 2010). These are the only claims authorised in the European Union for this mineral in relation to the nervous system.

^*Claims authorised by EFSA in accordance with Regulation (EC) No 1924/2006 on nutrition and health claims.

What ashwagandha is and how it acts on stress

Ashwagandha (Withania somnifera) is a plant of the Solanaceae family native to the Indian subcontinent. Its roots and leaves contain bioactive compounds called withanolides, which are the main drivers of its documented pharmacological effects.

It is classified as an adaptogen: a substance that helps the body adapt to situations of physical, chemical or biological stress without significantly altering normal physiological functions. This concept, although rooted in herbal medicine, has gained scientific support over the past 15 years through controlled clinical trials.

How exactly does it act? Clinical research on ashwagandha has explored its influence on the HPA axis and cortisol levels. A randomised, double-blind clinical trial in 64 adults with chronic stress (Chandrasekhar et al., 2012) found that 300 mg twice daily (600 mg/day total) of ashwagandha root extract over 60 days significantly reduced serum cortisol levels compared with placebo (p=0.0006).

A systematic review (Pratte et al., 2014, PMID: 25405876) that included studies up to 2013 found significant reductions on validated stress and anxiety scales—such as the Perceived Stress Scale and the Hamilton Anxiety Rating Scale—in participants who took standardised ashwagandha extract versus placebo, although the authors noted that the evidence was promising but preliminary.

There is a second pathway of action worth mentioning, albeit with important caveats. Studies in animal models have documented anxiolytic activity of ashwagandha's glycowithanolides (Bhattacharya et al., 2000). The specific molecular mechanism—possible modulation of GABAergic neurotransmission has been proposed—has not been conclusively confirmed in human clinical trials, so it should be interpreted with caution.

A relevant regulatory note: EFSA has not approved any specific health claim for ashwagandha in the European Union. This means that no product marketed in the EU can legally state that ashwagandha “reduces stress” or “lowers cortisol.” The scientific evidence exists, but the European regulatory framework has not yet translated it into authorised claims.

Why it makes sense to combine magnesium and ashwagandha for stress

The rationale for combining magnesium and ashwagandha rests on the fact that they act on stress through complementary, not redundant, mechanisms. Magnesium operates mainly at the level of neuronal excitability (the NMDA receptor) and the electrolyte balance of the nervous system; clinical research on ashwagandha has explored its influence on the HPA hormonal axis and cortisol levels (Chandrasekhar et al., 2012).

This complementarity matters because chronic stress is a multidimensional phenomenon: it simultaneously involves neuronal overactivation, sustained cortisol elevation, sleep disturbances, fatigue and cognitive dysfunction. An intervention that addresses only one of these mechanisms will have a limited reach.

Is there direct evidence for the combination?

This is the most important question, and the honest answer is: direct evidence on the specific magnesium + ashwagandha combination is limited. Most available studies evaluate each ingredient separately. As of the publication date of this article, there is no large-scale randomised clinical trial that has specifically evaluated this combination against placebo in humans.

What does exist is solid indirect evidence:

• Studies with multi-ingredient formulas that include magnesium and ashwagandha among other ingredients have shown reductions on perceived-stress scales. However, these studies do not allow the effect to be attributed to any specific ingredient.
• Mechanistic plausibility: the complementarity of their mechanisms of action is well documented in the stress neurobiology literature.
• Safety of the combination: no adverse interactions between magnesium and ashwagandha have been described in the available literature, and their individual safety profile is favourable when used at the studied doses.

The scientifically honest conclusion is that the combination has a solid mechanistic basis and a favourable safety profile, but direct clinical evidence on its specific synergy is still pending more robust studies.

Documented benefits of each one: what the evidence says

Below are the benefits with the strongest scientific support for each ingredient, distinguishing the level of evidence available.

Magnesium: what research in humans has observed

Research on subjective anxiety
The systematic review by Boyle et al. (2017), which analysed 18 studies, found that magnesium supplementation was associated with improvements in measures of subjective anxiety. The effect was more pronounced in people with a prior magnesium deficit and in those with mild-to-moderate anxiety.

Research on sleep quality
A double-blind clinical trial in 46 older adults (Abbasi et al., 2012) documented that 500 mg/day of magnesium over 8 weeks was associated with significant changes in sleep quality measured with the Insomnia Severity Index (ISI, p=0.006), in sleep latency (p=0.02) and in total sleep time (p=0.002) compared with placebo.

Normal psychological function^* (EFSA-approved claim)
EFSA recognises that magnesium contributes to normal psychological function, which includes mood and emotional response (EFSA, 2010).

Reduction of fatigue^*
Magnesium contributes to the reduction of tiredness and fatigue, another EFSA-approved claim, relevant in the context of chronic stress, which is frequently accompanied by exhaustion.

^*Claims authorised by EFSA in accordance with Regulation (EC) No 1924/2006 on nutrition and health claims.

Ashwagandha: available clinical evidence

Clinical evidence on perceived stress
A randomised, double-blind clinical trial (Chandrasekhar et al., 2012) in 64 adults found that 300 mg twice daily of standardised root extract over 60 days significantly reduced Perceived Stress Scale (PSS) scores compared with placebo (p<0.0001).

Serum cortisol: results of the Chandrasekhar et al. (2012) trial
The same study recorded a significant reduction in serum cortisol in the ashwagandha group compared with placebo (p=0.0006), which remained robust throughout the intervention period. This reduction was statistically significant and represents one of the most consistently replicated effects in clinical research with ashwagandha.

Clinical evidence on sleep quality
A clinical trial in 80 participants (40 healthy adults + 40 with insomnia) (Langade et al., 2021) documented significant changes in sleep quality measured with the Pittsburgh Sleep Quality Index (PSQI), sleep latency and sleep efficiency compared with placebo.

Clinical evidence on cognitive performance under stress
A clinical trial in 50 adults (Choudhary et al., 2017) recorded that 300 mg twice daily of ashwagandha extract over 8 weeks was associated with significant changes in tests of immediate and general memory, executive function, processing speed and sustained attention compared with placebo (p<0.05 across all measures).

Note on levels of evidence: The studies cited are randomised, double-blind clinical trials—the most methodologically rigorous design available for evaluating supplements. The sample sizes are moderate (46-150 participants). Studies with larger numbers of participants and long-term follow-up are needed to confirm these results.

Forms of magnesium: not all are the same

One of the most relevant—and frequently overlooked—aspects when choosing a magnesium supplement is the chemical form of the mineral. Bioavailability varies significantly between forms, and not all are equally suitable for the goal of stress management.

Magnesium bisglycinate
This is the chelate of magnesium with glycine, an amino acid with inhibitory properties in the central nervous system. It is the form with the highest documented oral bioavailability and the best gastrointestinal tolerance. Glycine on its own has documented relaxing effects (Bannai & Kawai, 2012), which may enhance the effects of magnesium in the context of stress. It is the form with the strongest scientific support when the main goal is the nervous system.

Magnesium citrate
A combination of magnesium with citric acid. It has good bioavailability (higher than oxide) and is one of the most studied forms. It can have a laxative effect at high doses, which limits its use in people with digestive sensitivity.

Magnesium malate
A combination with malic acid, an intermediate in the Krebs cycle (cellular energy production). It may be especially useful when fatigue is the predominant symptom, although the specific evidence in humans is more limited than for bisglycinate or citrate.

Magnesium oxide
This is the cheapest and most common form in low-cost supplements. Its oral bioavailability is significantly lower than that of chelated forms: a comparative study (Lindberg et al., 1990) found that urinary magnesium absorption after an oral dose of oxide was much lower than that of citrate (urinary increase of 0.006 versus 0.22 mg/mg of creatinine; p<0.05). Its main use is as an osmotic laxative, not as a nutritional supplement.

Magnesium threonate (L-threonate)
A form developed specifically to cross the blood-brain barrier. Studies in animal models (Slutsky et al., 2010) showed significant increases in magnesium concentration in the cerebrospinal fluid and improvements in cognitive function. Studies in humans are promising but still limited in number and sample size (Liu et al., 2016).

For the specific goal of supporting the nervous system, magnesium bisglycinate is the form with the strongest scientific support and the best tolerability profile. If you want to dig deeper into the comparison between the two most common forms, you can read our guide on magnesium bisglycinate vs. citrate.

Forms of ashwagandha: standardised extracts vs. root powder

As with magnesium, not all ashwagandha preparations are equivalent. The concentration of withanolides—the bioactive compounds responsible for its effects—varies enormously between products.

Standardised root extract
This is the form used in most clinical trials with positive results. Standardised extracts guarantee a minimum percentage of withanolides (typically 2.5%-5% or higher). The most studied are:

• KSM-66®: a root extract standardised to 5% withanolides, with more than 20 published clinical trials. It is the extract with the largest number of human studies.
• Sensoril®: a root and leaf extract standardised to 10% withanolides. It has solid studies in stress and general well-being.
• Shoden®: an extract standardised to 35% withanolide glycosides. Preliminary studies show effects at lower doses (120 mg/day).

Non-standardised root powder
This is the cheapest and least predictable form. The concentration of withanolides varies between batches and suppliers. Clinical studies with non-standardised root powder show more inconsistent results. For use with a defined goal, standardised extracts offer greater reproducibility and scientific support.

Doses used in clinical studies:

• 600 mg/day (300 mg twice daily) of ashwagandha root extract (Langade et al., 2021)
• 600 mg/day (300 mg twice daily) of standardised full-spectrum root extract (Chandrasekhar et al., 2012)
• 300 mg twice daily of KSM-66® extract (Choudhary et al., 2017)
• 600 mg/day of KSM-66® extract (Wankhede et al., 2015)

The doses most frequently evaluated in clinical research are 300-600 mg/day of standardised extract, taken preferably with meals to improve absorption and reduce the likelihood of gastrointestinal discomfort.

Important: These are the doses recorded in the clinical research protocols cited. They do not constitute a dose recommendation for any individual. Always consult your doctor or pharmacist before starting any supplementation.

How to take magnesium and ashwagandha together: what the studies say

If you decide to incorporate both food supplements, there are a few practical considerations supported by the available evidence.

Can they be taken together or separately?
There is no evidence of pharmacological interactions between magnesium and ashwagandha. Magnesium is absorbed mainly in the small intestine through specific transporters; ashwagandha's withanolides are lipophilic compounds that are absorbed by passive diffusion. Their absorption routes do not compete with each other, so taking them together should not reduce the bioavailability of either one.

Time of day
The evidence on the optimal time to take them is limited, but there are some pointers derived from the study protocols:

• Magnesium (especially bisglycinate) was frequently administered in the late afternoon or evening in clinical trials on sleep and relaxation. Taking it with food reduces the risk of gastrointestinal discomfort.
• Ashwagandha was administered in divided doses (morning and evening) in some studies, and in a single dose in others. There is no consensus on the optimal timing in the available literature.
• Taking both in the evening, with dinner, is consistent with the protocols of the studies on sleep and relaxation.

Time until results are seen
Clinical studies with ashwagandha show significant effects from 4-8 weeks of continued use. Studies with magnesium show effects on sleep and anxiety within the same time range. Immediate effects should not be expected: both act gradually on physiological systems that need time to re-balance.

Duration of use
The available studies evaluate periods of 4 to 12 weeks. There are no long-term safety data (beyond 6 months) for ashwagandha in controlled clinical trials. Magnesium, being an essential mineral, can be taken on an ongoing basis as long as the tolerable upper intake levels set by EFSA are not exceeded (250 mg/day of supplemental magnesium for adults).

Important note: This information is for educational purposes and reflects the protocols used in clinical research. The decision about whether to take these supplements, at what dose and for how long should always be made with the guidance of a healthcare professional, especially if you are taking medication or have pre-existing health conditions.

Side effects and contraindications

Both magnesium and ashwagandha have favourable safety profiles when used at the studied doses. However, there are situations in which their use requires caution or is contraindicated.

Magnesium: side effects and contraindications

Most common side effects:

• Gastrointestinal discomfort (diarrhoea, nausea) at high doses, especially with low-bioavailability forms such as magnesium oxide. Bisglycinate and citrate are better tolerated.
• Osmotic diarrhoea is the most common adverse effect and usually resolves by reducing the dose or changing the magnesium form.

Contraindications and precautions:

• Kidney failure: the kidneys are the main regulators of magnesium excretion. In people with reduced kidney function, supplementation can cause hypermagnesaemia (excess magnesium in the blood), a potentially serious condition. Contraindicated without medical supervision in kidney failure.
• Medications: magnesium can reduce the absorption of certain antibiotics (tetracyclines, fluoroquinolones) and bisphosphonates if taken at the same time. It is recommended to separate intake by at least 2 hours.
• Calcium channel blockers: it may enhance their effects. Consult your doctor.

Tolerable upper intake level (EFSA): 250 mg/day of supplemental magnesium for adults (this does not include magnesium from the diet).

Ashwagandha: side effects and contraindications

Most common side effects:

• Mild gastrointestinal discomfort (nausea, dyspepsia) in some users, especially on an empty stomach. Taking it with food reduces this risk.
• Drowsiness in some cases, especially at high doses.

Contraindications and precautions:

• Pregnancy: ashwagandha is contraindicated during pregnancy. Studies in animal models and clinical cases suggest uterotonic properties that could increase the risk of miscarriage.
• Breastfeeding: there are not enough safety data. It is recommended to avoid it.
• Autoimmune diseases (lupus, rheumatoid arthritis, multiple sclerosis): ashwagandha may stimulate the immune system, which could exacerbate these conditions. Use only under medical supervision.
• Hypothyroidism and hyperthyroidism: some studies suggest that ashwagandha may raise thyroid hormone levels (T3 and T4). People with thyroid conditions or who take thyroid medication should consult their doctor before using it.
• Sedative and anti-anxiety medications: it may enhance their effects. Consult your doctor or pharmacist.
• Scheduled surgery: it is recommended to stop ashwagandha at least 2 weeks before a surgical procedure because of its possible effects on the central nervous system and blood pressure.

Hepatotoxicity (rare cases): Isolated cases of liver injury associated with the use of ashwagandha have been published, although causality has not been definitively established in all cases (Björnsson et al., 2020, PMID: 31991029). The incidence appears to be very low, but it is a relevant fact that healthcare professionals should be aware of.

Conclusion on safety: For healthy adults without pre-existing medical conditions or chronic medication, the use of magnesium and ashwagandha at the studied doses has a favourable safety profile. If you have any doubts, always consult your doctor or pharmacist.

Frequently asked questions about magnesium and ashwagandha together

Can you take magnesium and ashwagandha together every day?

Yes, there is no evidence of adverse interactions between the two. Clinical trials with ashwagandha have evaluated daily use over periods of 4 to 12 weeks with a good safety profile. Magnesium can be taken on an ongoing basis within the recommended intake limits. Consult your doctor or pharmacist to assess whether it is suitable in your specific case.

How long does it take to notice an effect?

Clinical studies show that significant effects on perceived stress and cortisol appear from 4-8 weeks of continued use. These are not fast-acting supplements: they act gradually on physiological systems that need time to re-balance. The effects on rest documented with magnesium in some studies were observed within a range of 2 to 4 weeks.

Which form of magnesium is best for stress?

Magnesium bisglycinate is the form with the strongest scientific support for the goal of supporting the nervous system. It combines high bioavailability, excellent gastrointestinal tolerance and the presence of glycine, an amino acid with inhibitory properties in the central nervous system. Magnesium citrate is also a valid option with good bioavailability.

Is ashwagandha addictive?

There is no evidence that ashwagandha causes physical dependence or withdrawal syndrome when discontinued. The available studies have not reported this type of effect. However, long-term research (beyond 6 months) is limited, so it is recommended to take periodic breaks and consult a healthcare professional about the optimal duration of use.

Can people undergoing treatment affecting the nervous system take magnesium and ashwagandha?

People undergoing drug treatment that affects the central nervous system (anti-anxiety medication, antidepressants or others) must consult their doctor or pharmacist before adding any supplement. Ashwagandha may interact with central nervous system medications. Magnesium can also interact with certain drugs. Supplements are not a substitute for any prescribed medical treatment.

Is KSM-66 ashwagandha the same as generic ashwagandha?

No. KSM-66® is a root extract standardised to 5% withanolides, with more than 20 published clinical trials. Generic ashwagandha (non-standardised root powder) has a variable and unpredictable withanolide concentration between batches. For use with a defined goal, standardised extracts offer greater reproducibility and scientific support.

Conclusion

Magnesium and ashwagandha are two of the ingredients with the strongest scientific support in the field of nervous system function and stress research. Their combination has a solid mechanistic basis: they act on complementary pathways—neuronal excitability and the hormonal axis of stress—without interfering with each other.

The available evidence on each one separately is consistent: magnesium contributes to the normal functioning of the nervous system^* and to normal psychological function^* (EFSA-approved claims); ashwagandha has been evaluated in multiple controlled clinical trials that have explored its influence on serum cortisol and perceived stress, with results that EFSA has not yet translated into authorised claims in the EU.

Direct evidence on the specific combination is still limited, and clinical trials designed specifically to evaluate it are needed. This does not invalidate its use, but it does call for realistic expectations: these are not fast-acting solutions. They are supportive tools that, within the context of a healthy lifestyle, may contribute to the normal functioning of the nervous system^*—in the case of magnesium, with regulatory backing—and to general well-being.

If you are considering adding magnesium and ashwagandha to your routine, prioritise forms of proven quality (magnesium bisglycinate; standardised ashwagandha extract such as KSM-66® or Sensoril®), keep in mind the doses evaluated in the studies and always consult your doctor or pharmacist, especially if you have pre-existing health conditions or take medication.

^*Claims authorised by EFSA in accordance with Regulation (EC) No 1924/2006 on nutrition and health claims.

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References

• Pickering G, Mazur A, Trousselard M, et al. Magnesium Status and Stress: The Vicious Circle Concept Revisited. Nutrients. 2020;12(12):3672. PMID: 33260549.
• Boyle NB, Lawton C, Dye L. The Effects of Magnesium Supplementation on Subjective Anxiety and Stress—A Systematic Review. Nutrients. 2017;9(5):429. PMID: 28445426.
• Chandrasekhar K, Kapoor J, Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian J Psychol Med. 2012;34(3):255-62. PMID: 23439798.
• Pratte MA, Nanavati KB, Young V, Morley CP. An alternative treatment for anxiety: a systematic review of human trial results reported for the Ayurvedic herb ashwagandha (Withania somnifera). J Altern Complement Med. 2014;20(12):901-8. PMID: 25405876.
• Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B. The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. J Res Med Sci. 2012;17(12):1161-9. PMID: 23853635.
• Langade D, Thakare V, Kanchi S, Kelgane S. Clinical evaluation of the pharmacological impact of ashwagandha root extract on sleep in healthy volunteers and insomnia patients: A double-blind, randomized, parallel-group, placebo-controlled study. J Ethnopharmacol. 2021;264:113276. PMID: 32818573.
• Choudhary D, Bhattacharyya S, Bose S. Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions. J Diet Suppl. 2017;14(6):599-612. PMID: 28471731.
• Wankhede S, Langade D, Joshi K, Sinha SR, Bhattacharyya S. Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. J Int Soc Sports Nutr. 2015;12:43. PMID: 26609282.
• Bhattacharya SK, Bhattacharya A, Sairam K, Ghosal S. Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study. Phytomedicine. 2000;7(6):463-9. PMID: 11194174.
• Björnsson HK, Björnsson ES, Avula B, et al. Ashwagandha-induced liver injury: A case series from Iceland and the US Drug-Induced Liver Injury Network. Liver Int. 2020;40(4):825-829. PMID: 31991029.
• Bannai M, Kawai N. New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. J Pharmacol Sci. 2012;118(2):145-8. PMID: 22293292.
• Lindberg JS, Zobitz MM, Poindexter JR, Pak CY. Magnesium bioavailability from magnesium citrate and magnesium oxide. J Am Coll Nutr. 1990;9(1):48-55. PMID: 2407766.
• Slutsky I, Abumaria N, Wu LJ, et al. Enhancement of learning and memory by elevating brain magnesium. Neuron. 2010;65(2):165-77. PMID: 20152124.
• Liu G, Weinger JG, Lu ZL, Xue F, Sadeghpour S. Efficacy and Safety of MMFS-01, a Synapse Density Enhancer, for Treating Cognitive Impairment in Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial. J Alzheimers Dis. 2016;49(4):971-90. PMID: 26519439.
• European Food Safety Authority (EFSA). Scientific Opinion on the substantiation of health claims related to magnesium. EFSA Journal. 2010;8(10):1807. EFSA Journal 8(10):1807.