The research library

What the research says about each ingredient.

Short summaries of human research on each ingredient: what was studied, how much, and for how long. Open any ingredient's studies for the details and a link to the original paper.

"Peer-reviewed" means published in a peer-reviewed journal. We label industry-funded studies, and we include ones that found little or no effect.

Group one

Active ingredients

Five botanicals and amino acids, each with human research on stress, calm, sleep or focus.

01 · Active ingredient

Ashwagandha

Withania somnifera · root extract

A herb used for centuries in Ayurvedic tradition and classed as an adaptogen. It is one of the most studied botanicals for stress, with trials also looking at sleep, memory and strength.

Stress
Cortisol
Sleep
Memory & focus
Strength
Testosterone
Menopause

Doses used in the research

Dose studied	Time	What the studies found
240 mg/day	60 days	Lower morning cortisol and anxiety scores (Study 2)
300–600 mg/day	varies	The range with the clearest stress benefit across 12 trials (Study 3)
600 mg/day	8 weeks	Better memory and attention (Study 6); bigger strength gains with training (Study 7); higher testosterone in men aged 40–70 (Study 8); fewer perimenopause symptoms (Study 10)
600 mg/day	60 days	Lower stress scores and cortisol (Study 1)
600 mg/day	10 weeks	Fell asleep faster, better sleep quality (Study 4). Sleep effects were strongest at 600 mg or more for 8 weeks or longer (Study 5)
600 mg/day	12 weeks	Better sleep and fewer menopause symptoms after menopause (Study 11)

See the 11 studies behind this

StressStudy 1

Lower stress scores and cortisol after 60 days

What they did: 64 adults with chronic stress; randomised, double-blind, placebo-controlled, 60 days.
What they found: Stress-scale scores fell significantly more than placebo on every scale used, and serum cortisol dropped significantly.
Dose studied: 600 mg/day (300 mg twice daily)

✓ Peer-reviewedRandomised controlled trial

Chandrasekhar et al., Indian Journal of Psychological Medicine, 2012 Read the study ↗

Stress hormonesStudy 2

Lower morning cortisol in stressed adults

What they did: 60 stressed but healthy adults; randomised, double-blind, 60 days.
What they found: Anxiety scores on the HAM-A (Hamilton Anxiety Rating Scale) fell more than placebo and morning cortisol dropped significantly. A second stress questionnaire, the DASS-21 (Depression Anxiety Stress Scales), did not reach significance.
Dose studied: 240 mg/day

✓ Peer-reviewedRandomised controlled trialLead author has had past funding from the extract maker

Lopresti et al., Medicine, 2019 Read the study ↗

Stress & anxietyStudy 3

Consistent reduction across 12 trials

What they did: Meta-analysis pooling 12 randomised trials with 1,002 adults.
What they found: Stress and anxiety scores fell versus placebo; the stress benefit was seen at 300–600 mg/day. The authors rate the certainty of evidence as low and call for higher-quality trials.
Dose studied: Various (clearest stress effect at 300–600 mg/day)

✓ Peer-reviewedMeta-analysis

Akhgarjand et al., Phytotherapy Research, 2022 Read the study ↗

SleepStudy 4

Fell asleep faster, slept more efficiently

What they did: 60 adults with insomnia and anxiety; randomised, double-blind, 10 weeks; sleep measured with wrist actigraphy and questionnaires.
What they found: Shorter time to fall asleep, and better sleep efficiency and sleep quality, than placebo.
Dose studied: 600 mg/day (300 mg twice daily)

✓ Peer-reviewedRandomised controlled trial

Langade et al., Cureus, 2019 Read the study ↗

SleepStudy 5

Small but significant improvement across 5 trials

What they did: Meta-analysis of 5 randomised trials with 400 adults.
What they found: A small, significant improvement in overall sleep, larger in people with insomnia, at 600 mg/day or more, and after 8 weeks or longer. Alertness on waking also improved.
Dose studied: Various

✓ Peer-reviewedMeta-analysis

Cheah et al., PLOS ONE, 2021 Read the study ↗

Memory & focusStudy 6

Better memory and attention scores

What they did: 50 adults with mild memory decline; randomised, double-blind, 8 weeks.
What they found: Immediate and general memory, attention and processing speed improved more than placebo.
Dose studied: 600 mg/day (300 mg twice daily)

✓ Peer-reviewedRandomised controlled trial (pilot)

Choudhary et al., Journal of Dietary Supplements, 2017 Read the study ↗

Strength & recoveryStudy 7

Greater strength gains with training

What they did: 57 young men starting resistance training; randomised, double-blind, 8 weeks.
What they found: Bigger gains in bench-press and leg-extension strength and in muscle size, a better recovery marker (creatine kinase), and a larger rise in testosterone than placebo.
Dose studied: 600 mg/day (300 mg twice daily)

✓ Peer-reviewedRandomised controlled trial

Wankhede et al., Journal of the International Society of Sports Nutrition, 2015 Read the study ↗

TestosteroneStudy 8

Higher testosterone in men over 40

What they did: 57 overweight men aged 40–70 with mild fatigue; randomised, double-blind, placebo-controlled crossover, 8 weeks per phase.
What they found: Testosterone rose 14.7% more than on placebo, and DHEA-S (another hormone) 18% more. Fatigue, vigour and sexual well-being improved in both groups, with no difference between them.
Dose studied: 600 mg/day

✓ Peer-reviewedRandomised controlled trial

Lopresti et al., American Journal of Men's Health, 2019 Read the study ↗

HormonesStudy 9

Testosterone up in men across 23 trials

What they did: Systematic review and meta-analysis of 23 randomised, placebo-controlled trials with 1,706 adults.
What they found: Testosterone rose in men (on average about 57 ng/dL more than placebo) but not in women, and cortisol fell. The authors note results varied between trials.
Dose studied: Various

✓ Peer-reviewedMeta-analysis

Fornalik et al., Planta Medica, 2026 Read the study ↗

MenopauseStudy 10

Fewer menopause symptoms in perimenopause

What they did: 100 women with menopause symptoms during perimenopause (the years leading up to menopause); randomised, double-blind, placebo-controlled, 8 weeks.
What they found: Menopause symptom scores fell significantly more than placebo across mood, physical and urogenital symptoms, and menopause-specific quality of life improved. Estradiol rose and FSH (follicle-stimulating hormone) and LH (luteinising hormone) fell; testosterone did not change.
Dose studied: 600 mg/day (300 mg twice daily)

✓ Peer-reviewedRandomised controlled trial

Gopal et al., Journal of Obstetrics and Gynaecology Research, 2021 Read the study ↗

Menopause & sleepStudy 11

Better sleep and fewer symptoms after menopause

What they did: 66 postmenopausal women aged 45–65; randomised, double-blind, placebo-controlled, 12 weeks.
What they found: Sleep quality on the PSQI (Pittsburgh Sleep Quality Index) improved far more than placebo (−5.2 vs −0.8 points), as did menopause symptom scores (−8.1 vs −1.2) and quality of life. Bone density did not change.
Dose studied: 600 mg/day

✓ Peer-reviewedRandomised controlled trial

Obhrai et al., Menopause, 2026 Read the study ↗

02 · Active ingredient

L-Theanine

Amino acid found in tea leaves

An amino acid found almost only in tea. It is studied for a "relaxed but alert" state, and for its effects on stress and sleep.

Stress
Relaxed focus
Sleep

Doses used in the research

Dose studied	Time	What the studies found
50 mg, single dose	45–105 minutes	More "relaxed-alert" alpha brain-wave activity (Study 3)
200 mg/day	4 weeks	Better stress, sleep-quality and verbal-fluency scores (Study 1)

See the 4 studies behind this

Stress, sleep & focusStudy 1

Better stress, sleep and verbal-fluency scores in 4 weeks

What they did: 30 healthy adults; randomised, double-blind, placebo-controlled crossover, 4 weeks per phase.
What they found: Stress-related symptoms improved, including anxiety and sleep-quality scores; time to fall asleep and sleep disturbance fell; verbal fluency and executive function improved.
Dose studied: 200 mg/day

✓ Peer-reviewedRandomised controlled trialFunded by the ingredient maker; its staff were co-authors

Hidese et al., Nutrients, 2019 Read the study ↗

Stress responseStudy 2

Calmer heart rate during a stressful task

What they did: 12 adults; double-blind crossover, with a mental-arithmetic stress task.
What they found: L-theanine reduced the rise in heart rate and in a salivary stress marker compared with placebo.
Dose studied: See study

✓ Peer-reviewedRandomised controlled trial (small)Co-authors from the ingredient maker

Kimura et al., Biological Psychology, 2007 Read the study ↗

Relaxed alertnessStudy 3

More "alpha" brain-wave activity

What they did: 35 young adults; brain activity measured by EEG (electroencephalography) 45–105 minutes after a single dose or placebo.
What they found: A greater increase in alpha activity, a pattern linked to a relaxed but alert state.
Dose studied: 50 mg, single dose

Short conference reportRun by a tea company (Unilever)

Nobre et al., Asia Pacific Journal of Clinical Nutrition, 2008 Read the study ↗

SleepStudy 4

Small improvements in sleep quality

What they did: Systematic review and meta-analysis of 19 studies with 897 participants.
What they found: Small but significant improvements in time to fall asleep, daytime dysfunction and overall sleep quality. The authors note few studies used L-theanine on its own.
Dose studied: Various

✓ Peer-reviewedMeta-analysis

Bulman et al., Sleep Medicine Reviews, 2025 Read the study ↗

03 · Active ingredient

GABA

Gamma-aminobutyric acid

The body's main calming messenger in the nervous system, also found in fermented foods. Studies have looked at relaxation, fatigue and sleep.

Relaxation
Fatigue
Sleep

Doses used in the research

Dose studied	Time	What the studies found
25 mg, single dose in a drink	during a long task	Lower salivary fatigue and stress markers (Study 2)
50 mg, single dose in a drink	during a long task	Also less felt fatigue and better task accuracy. In this study, 50 mg did more than 25 mg (Study 2)
Not stated in abstract	within 1 hour	More alpha brain waves (Study 1)

See the 3 studies behind this

RelaxationStudy 1

More alpha brain waves within an hour

What they did: Brain activity measured by EEG (electroencephalography) in 13 people after GABA (gamma-aminobutyric acid) or water; a second test in 8 people crossing a suspension bridge.
What they found: GABA (gamma-aminobutyric acid) increased alpha waves and reduced beta waves compared with water. On the bridge, a salivary immune marker held up better than with placebo.
Dose studied: See study

✓ Peer-reviewedSmall trialRun by an ingredient maker

Abdou et al., BioFactors, 2006 Read the study ↗

Mental & physical fatigueStudy 2

Less fatigue during a demanding task

What they did: 30 adults drank a beverage with 0, 25 or 50 mg GABA (gamma-aminobutyric acid) before a long arithmetic test.
What they found: 50 mg lowered how tired people felt; 25 and 50 mg both lowered salivary fatigue and stress markers (chromogranin A, cortisol); 50 mg also improved task accuracy.
Dose studied: 25–50 mg, single dose

✓ Peer-reviewedControlled trialBeverage-company study

Kanehira et al., Journal of Nutritional Science and Vitaminology, 2011 Read the study ↗

SleepStudy 3

Fell asleep faster in a small study

What they did: Randomised, single-blind, placebo-controlled crossover; sleep measured by EEG (electroencephalography).
What they found: Shorter time to fall asleep and more non-REM (non-rapid eye movement) sleep than placebo.
Dose studied: See study

✓ Peer-reviewedSmall trialRun by an ingredient maker

Yamatsu et al., Food Science and Biotechnology, 2016 Read the study ↗

04 · Active ingredient

Lemon Balm

Melissa officinalis · leaf extract

A lemon-scented herb from the mint family, used in European herbal tradition. Trials have looked at calm under stress, anxiety and sleep.

Calm
Anxiety
Sleep

Doses used in the research

Dose studied	Time	What the studies found
300 mg, single dose	1 hour	Faster arithmetic with no loss of accuracy (Study 1)
600 mg, single dose	1 hour	Calmer during a lab stress test (Study 1)
400 mg/day, phytosome form, evenings	2 weeks	Better sleep scores (Study 3)

See the 3 studies behind this

Calm under stressStudy 1

Calmer during a lab stress test

What they did: 18 healthy adults; double-blind, placebo-controlled crossover, single doses.
What they found: 600 mg increased self-rated calmness during a stress test. 300 mg sped up arithmetic with no loss of accuracy.
Dose studied: 300 mg and 600 mg, single doses

✓ Peer-reviewedRandomised controlled trial

Kennedy et al., Psychosomatic Medicine, 2004 Read the study ↗

AnxietyStudy 2

Lower anxiety scores; results vary

What they did: Systematic review and meta-analysis of randomised trials.
What they found: Lemon balm lowered anxiety scores compared with placebo, especially with short-term use, without serious side effects. The authors caution that trials were few and varied a lot.
Dose studied: Various

✓ Peer-reviewedMeta-analysis

Ghazizadeh et al., Phytotherapy Research, 2021 Read the study ↗

SleepStudy 3

Better sleep scores with an enhanced-absorption form

What they did: 30 adults; double-blind, placebo-controlled crossover with two 2-week periods, using a "phytosome" form designed for better absorption.
What they found: Insomnia-severity scores improved (6.8 vs 9.7 on placebo), and 87% reported better sleep vs 30% on placebo.
Dose studied: 400 mg/day phytosome, in the evening

✓ Peer-reviewedRandomised controlled trialLead author directs the ingredient maker

Di Pierro et al., Nutrients, 2024 Read the study ↗

05 · Active ingredient

Chamomile

Matricaria chamomilla · flower extract

A daisy-like flower best known as a bedtime tea. Clinical trials have looked at anxiety and sleep quality.

Anxiety
Sleep
PMS (premenstrual syndrome)

Doses used in the research

Dose studied	Time	What the studies found
300 mg/day	2 menstrual cycles	Fewer emotional PMS (premenstrual syndrome) symptoms (Study 5)
400 mg/day	28 days	Better sleep quality in adults aged 60+ (Study 3)
220–1,100 mg/day, increased gradually	8 weeks	Modest drop in anxiety symptoms (Study 1)
1,500 mg/day	26 weeks	Anxiety symptoms stayed lower than placebo (Study 2)

See the 5 studies behind this

AnxietyStudy 1

Modest reduction in anxiety symptoms

What they did: 57 adults with mild-to-moderate generalised anxiety disorder; randomised, double-blind, 8 weeks.
What they found: Anxiety scores on the HAM-A (Hamilton Anxiety Rating Scale) fell significantly more than placebo; the authors describe the effect as modest.
Dose studied: 220–1,100 mg/day, increased gradually

✓ Peer-reviewedRandomised controlled trial

Amsterdam et al., Journal of Clinical Psychopharmacology, 2009 Read the study ↗

Anxiety, long termStudy 2

Lower symptoms over 26 weeks

What they did: 93 people who had responded to chamomile were randomised to continue it or switch to placebo for 26 weeks.
What they found: The chamomile group kept significantly lower anxiety symptoms. The difference in relapse rate was not statistically significant.
Dose studied: 1,500 mg/day

✓ Peer-reviewedRandomised controlled trial

Mao et al., Phytomedicine, 2016 Read the study ↗

SleepStudy 3

Better sleep quality in older adults

What they did: 60 adults aged 60 and over; randomised, single-blind, 28 days.
What they found: Sleep quality on the PSQI (Pittsburgh Sleep Quality Index) was significantly better than in the control group.
Dose studied: 400 mg/day (200 mg twice daily)

✓ Peer-reviewedRandomised controlled trial

Adib-Hajbaghery & Mousavi, Complementary Therapies in Medicine, 2017 Read the study ↗

Sleep & anxietyStudy 4

Sleep quality improved; mixed elsewhere

What they did: Systematic review and meta-analysis of 12 trials.
What they found: Significant improvement in sleep quality and in generalised anxiety disorder; no difference for short-term anxiety or insomnia severity.
Dose studied: Various

✓ Peer-reviewedMeta-analysis

Hieu et al., Phytotherapy Research, 2019 Read the study ↗

PMS (premenstrual syndrome)Study 5

Fewer emotional PMS (premenstrual syndrome) symptoms

What they did: 90 university students with diagnosed PMS (premenstrual syndrome); randomised, double-blind, comparing chamomile with mefenamic acid (a common period-pain medicine) over two menstrual cycles. There was no placebo group.
What they found: Emotional symptoms fell by about 30% with chamomile vs about 11% with mefenamic acid. Physical symptoms improved similarly in both groups.
Dose studied: 300 mg/day (100 mg three times daily)

✓ Peer-reviewedRandomised controlled trial

Sharifi et al., Complementary Therapies in Clinical Practice, 2014 Read the study ↗

Group two

Functional ingredients

Five more ingredients with their own human research, from sleep and stress hormones to digestion and hydration.

06 · Functional ingredient

Glycine

Amino acid

One of the amino acids the body uses as a building block for protein. It has been studied for its role in sleep.

Sleep
Next-day fatigue

Doses used in the research

Dose studied	Time	What the studies found
3 g, before bed	3 nights of short sleep	Less next-day fatigue and better reaction-time results (Study 1)

See the 1 study behind this

Sleep & next-day fatigueStudy 1

Less fatigue after short sleep

What they did: Healthy adults had their sleep cut by 25% for 3 nights and took glycine or placebo before bed.
What they found: Less next-day fatigue, a trend toward less sleepiness, and better reaction-time test results.
Dose studied: 3 g before bed

✓ Peer-reviewedControlled trialRun by an ingredient maker

Bannai et al., Frontiers in Neurology, 2012 Read the study ↗

07 · Functional ingredient

Phosphatidylserine-Enriched Soy Lecithin

Phospholipid from soy

Lecithin is a natural fat-based substance found in foods like soy and eggs. This form is enriched with PS (phosphatidylserine), a fat found in every cell membrane and studied for stress and memory.

Stress hormones
Memory

Doses used in the research

Dose studied	Time	What the studies found
100–300 mg/day PS (phosphatidylserine)	6 months	Better delayed recall, only in people who started with lower memory scores (Study 3)
400 mg/day PS (phosphatidylserine) complex	3 weeks	Blunted stress-hormone response to a stress test. 600 and 800 mg did not: in this study, more was not better (Study 1)
400 mg PS (phosphatidylserine) + 400 mg PA (phosphatidic acid)/day	6 weeks	Normalised stress-hormone response in highly stressed men only (Study 2)
600 mg/day PS (phosphatidylserine)	10 days	Lower cortisol after exercise (Study 4)

See the 4 studies behind this

Stress hormonesStudy 1

Blunted cortisol response to a stress test

What they did: 80 adults took a soy PS (phosphatidylserine) complex for 3 weeks, then did a public-speaking stress test.
What they found: 400 mg blunted the stress-hormone response of ACTH (adrenocorticotropic hormone) and cortisol and reduced distress. Higher doses did not.
Dose studied: 400, 600 or 800 mg/day PS (phosphatidylserine) complex

✓ Peer-reviewedRandomised controlled trialCo-author from an ingredient company

Hellhammer et al., Stress, 2004 Read the study ↗

Stress hormonesStudy 2

Normalised stress response in high-stress men

What they did: 75 men; randomised, double-blind, 6 weeks, then a stress test.
What they found: The cortisol response normalised in men with high chronic stress only. No effect in low-stress men, or on how stressed people felt.
Dose studied: 400 mg PS (phosphatidylserine) + 400 mg PA (phosphatidic acid)/day

✓ Peer-reviewedRandomised controlled trialCo-author employed by the ingredient maker

Hellhammer et al., Lipids in Health and Disease, 2014 Read the study ↗

MemoryStudy 3

Memory gains only in people who started lower

What they did: 78 adults aged 50–69 with memory complaints; randomised, double-blind, 6 months.
What they found: Scores rose in every group, including placebo. People who started with lower scores improved delayed recall on PS (phosphatidylserine).
Dose studied: 100–300 mg/day soy PS (phosphatidylserine)

✓ Peer-reviewedRandomised controlled trialRun by a food company (Yakult)

Kato-Kataoka et al., Journal of Clinical Biochemistry and Nutrition, 2010 Read the study ↗

Exercise stressStudy 4

Lower cortisol after exercise

What they did: 10 men; double-blind crossover, 10 days per phase.
What they found: Peak cortisol after moderate exercise was lower than with placebo.
Dose studied: 600 mg/day

✓ Peer-reviewedRandomised controlled trial (small)Funded by an ingredient company

Starks et al., Journal of the International Society of Sports Nutrition, 2008 Read the study ↗

08 · Functional ingredient

Fibersol-2

Soluble fibre (resistant maltodextrin)

A soluble fibre made from corn starch that dissolves clear in water. It is studied for digestive regularity, gut bacteria and fullness after meals.

Regularity
Gut bacteria
Fullness
Blood fats after meals

Doses used in the research

Dose studied	Time	What the studies found
5–10 g with a fatty meal	after the meal	Smaller rise in blood fats (triglycerides) after eating (Study 5)
10 g with a meal	1.5–2 hours	Less hunger and more fullness; higher GLP-1 (glucagon-like peptide-1) and PYY (peptide YY). 5 g did not show this (Study 4)
15 g/day	3 weeks	Faster digestive transit and more stool volume (Study 2)
25 g/day	3 weeks	More beneficial bifidobacteria. 15 g did not show this (Study 3)

See the 5 studies behind this

RegularityStudy 1

More frequent, fuller bowel movements

What they did: Meta-analysis of 29 randomised trials.
What they found: Stool frequency and volume increased compared with placebo.
Dose studied: Various

✓ Peer-reviewedMeta-analysisCo-author employed by the ingredient maker

Watanabe et al., Clinical and Experimental Gastroenterology, 2018 Read the study ↗

Digestive transitStudy 2

Faster transit and more stool volume

What they did: 66 adults without a daily bowel movement; randomised, double-blind, 3 weeks.
What they found: Faster colonic transit and better stool consistency than placebo; stool volume rose 56% from where people started.
Dose studied: 15 g/day

✓ Peer-reviewedRandomised controlled trial

Abellán Ruiz et al., European Journal of Nutrition, 2016 Read the study ↗

Gut bacteriaStudy 3

More bifidobacteria, at the higher dose only

What they did: 51 adults took 0, 15 or 25 g/day for 3 weeks each.
What they found: Only 25 g/day increased beneficial bifidobacteria.
Dose studied: 15–25 g/day

✓ Peer-reviewedRandomised controlled trialCo-author employed by the ingredient maker

Burns et al., Nutrition Research, 2018 Read the study ↗

FullnessStudy 4

Less hunger after a meal, with more GLP-1 (glucagon-like peptide-1) and PYY (peptide YY)

What they did: 19 healthy adults (9 men, 10 women); randomised, double-blind, placebo-controlled crossover. Each had the same meal with a tea containing 0, 5 or 10 g of Fibersol-2.
What they found: 10 g delayed hunger and increased fullness for 1.5–2 hours after the meal, and raised the gut fullness hormones GLP-1 (glucagon-like peptide-1) and PYY (peptide YY) compared with 0 or 5 g. 5 g made no difference.
Dose studied: 10 g with a meal (5 g had no effect)

✓ Peer-reviewedRandomised controlled trialCo-author employed by the ingredient maker

Ye et al., Nutrition Research, 2015 Read the study ↗

Blood fats after mealsStudy 5

Smaller rise in blood fats after a fatty meal

What they did: 13 healthy adults ate a high-fat meal (about 50 g of fat) with a drink containing 0, 5 or 10 g of resistant maltodextrin.
What they found: Both 5 g and 10 g significantly reduced the rise in blood triglycerides and remnant cholesterol after the meal compared with placebo.
Dose studied: 5–10 g with a meal

✓ Peer-reviewedControlled trialRun by the ingredient maker

Kishimoto et al., European Journal of Nutrition, 2007 Read the study ↗

09 · Functional ingredient

Malic Acid

Fruit acid

The natural acid that gives apples their tartness. In the body it exists as malate, one of the steps of the Krebs cycle, the process cells use to make energy.

Muscle pain
Krebs cycle

The biology: malate in the Krebs cycle

Inside every cell, the mitochondria run the Krebs (citric acid) cycle: an eight-step loop that breaks down fuel from carbohydrates, fats and proteins.
1. Late in the loop, fumarate is converted into malate.
2. Malate is then converted into oxaloacetate. This step loads a carrier molecule called NADH (nicotinamide adenine dinucleotide).
3. Oxaloacetate joins a new fuel molecule, acetyl-CoA (acetyl coenzyme A), and the loop starts again.
4. NADH carries its energy to the electron transport chain, which makes most of the cell's ATP (adenosine triphosphate), its energy currency.
Malate also helps move NADH into the mitochondria from the rest of the cell (the malate–aspartate shuttle).

Alabduladhem & Bordoni, Physiology, Krebs Cycle, StatPearls (NCBI Bookshelf), 2022Read more ↗

See the 1 study behind this

Muscle painStudy 1

No clear benefit found

What they did: An evidence summary of 7 systematic reviews on malic acid with magnesium for fibromyalgia.
What they found: Concluded it makes little or no difference to pain. We show this because the research is what it is.

✓ Peer-reviewedEvidence summary

Ferreira et al., Medwave, 2019 Read the study ↗

10 · Functional ingredient

Electrolytes

Minerals such as sodium

Minerals, including sodium, that the body uses to hold on to fluid.

Hydration

Doses used in the research

Dose studied	Time	What the studies found
1 L oral rehydration solution	over 4 hours	Kept more fluid in the body than still water (Study 1)
27–52 mmol/L sodium in 1 L	over 4 hours	Kept more fluid than 7–15 mmol/L (Study 2)

See the 2 studies behind this

HydrationStudy 1

Electrolyte drinks were retained better than water

What they did: 72 men drank 1 L of still water and 1 L of three other drinks on separate days (13 drinks were tested in all); urine was collected for 4 hours afterwards.
What they found: An oral rehydration solution, rich in electrolytes, was retained in the body better than still water over the following hours.
Dose studied: 1 L

✓ Peer-reviewedRandomised controlled trial

Maughan et al., American Journal of Clinical Nutrition, 2016 Read the study ↗

Sodium & fluid retentionStudy 2

More sodium kept more fluid in the body

What they did: 36 active men; double-blind crossover. Each drank 1 L of drinks with different sodium levels, and urine was collected for 4 hours afterwards.
What they found: Drinks with more sodium (27–52 mmol/L) were retained better than lower-sodium drinks.
Dose studied: 1 L at different sodium levels

✓ Peer-reviewedRandomised controlled trial

Maughan et al., International Journal of Sport Nutrition and Exercise Metabolism, 2019 Read the study ↗

For education only

This page summarises published research on individual ingredients. It describes what researchers found when they studied each ingredient, often at different doses, in different forms and in specific groups of people. It is not a description of what any product does and is not a claim that any product will produce these results.

This information is not medical advice and does not replace advice from a qualified healthcare professional. It is not intended to diagnose, treat, cure or prevent any disease. Individual responses vary. Speak with a healthcare practitioner before starting any new supplement, especially if you are pregnant or breastfeeding, take medication or have a medical condition.

Study links lead to independent third-party websites (journals and PubMed), whose content we do not control. Summaries were written from each study's published abstract or full text. Where a study was funded or run by an ingredient manufacturer, we say so.

Research last reviewed: October 12, 2026