INGREDIENT UNIVERSE
Scientific Knowledge
Explore supplement ingredients through questions tested in humans.
Read the findings, conditions and limitations together.
52 INGREDIENT RECORDS
Astaxanthin, CoQ10, magnesium and zinc: human studies recorded in a consistent format. Browse by ingredient and compare research questions.
The number of studies and the certainty of a particular effect are different things. Check who received what, how much, for how long, and what changed.
How to read the evidenceLÍFSVARÐA Knowledge is an information resource exploring scientific findings on a range of ingredients and healthy longevity. Inclusion in Knowledge does not mean that an ingredient is used, or planned for use, in a LÍFSVARÐA product.
52 ingredient records
Choose a substance, then compare questions—not just study counts. Each ingredient profile explains the material; the research records separate populations, preparations and outcomes. Related-topic links help you compare neighbouring questions without assuming equivalent effects.
Metabolism and cellular function
Human research at a glance
In a 12-week trial of 27 overweight or obese adults, astaxanthin lowered MDA and isoprostane and increased total antioxidant capacity versus placebo. These are blood biomarkers. Other trials examine lipids and vascular outcomes in different populations.
Detailed records: 3 / Literature map: 12
Human research at a glance
In adults with mild fatigue, a 12-week trial of ubiquinol 100 or 150 mg/day reported improvements in selected post-task fatigue and sleepiness ratings versus placebo. We examine this alongside the separate Q-SYMBIO heart-failure trial, keeping populations and CoQ10 forms distinct.
Detailed records: 2 / Literature map: 12
Metabolism and cellular function
Human research at a glance
Human trials now examine sleep and memory as well as absorption. A 16-week trial found better perceived sleep length and refreshing scores with 8 mg/day versus placebo. These were exploratory questionnaire outcomes; separate trials explore subjective memory and learning.
Detailed records: 4 / Literature map: 13
Human research at a glance
An eight-week trial in 70 adults with regular fatigue reported time-by-group differences in overall fatigue, work-related fatigue and anger–hostility. The intervention combined 5-ALA with iron; the control also contained iron. These are subjective outcomes under the studied conditions.
Detailed records: 2 / Literature map: 11
Metabolism and cellular function
Human research at a glance
Human spermidine research now reaches immune-cell biology. A 2026 pilot using 6 mg/day reported autophagy-related and antibody-response changes, particularly in a small subgroup with low vaccine responses. This exploratory immune finding is distinct from the earlier memory trials.
Detailed records: 3 / Literature map: 11
Human research at a glance
Human studies of PQQ have reported higher memory-test scores after 12 weeks and an increase in PGC-1α, a protein involved in mitochondrial signaling, in a separate 6-week exercise trial. These findings concern specific tests and biomarkers; the exercise trial did not show better aerobic performance than placebo.
Detailed records: 3 / Literature map: 11
Human research at a glance
A 10-week randomized trial in postmenopausal women with overweight or obesity and prediabetes reported improved muscle insulin sensitivity and associated signaling with NMN. The result concerns muscle metabolism in this population, rather than a general measure of rejuvenation.
Detailed records: 2 / Literature map: 11
Human research at a glance
A meta-analysis of 34 randomized trials involving 2,028 participants found small blood-pressure reductions with magnesium versus placebo: approximately 2.00 mmHg systolic and 1.78 mmHg diastolic. Baseline status, formulation and dose help interpret this average.
Detailed records: 1 / Literature map: 11
Human research at a glance
A 12-month trial in 50 adults aged 55–87 reported fewer infections and lower selected inflammatory and oxidative-stress markers with zinc than placebo. It used 45 mg elemental zinc/day, a study dose rather than a routine intake recommendation. Treating an existing cold with lozenges is a separate question.
Detailed records: 2 / Literature map: 11
Human research at a glance
Population: 69 trials involving 1,937 participants Findings: Pooled results improved for bench/chest press, squat, jump and Wingate outcomes. Overall analyses of handgrip and leg press were not significant.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 25,871 participants: men aged 50 or older and women aged 55 or older Findings: Major cardiovascular events: HR 0.92 (95% CI 0.80–1.06); cancer: HR 1.03 (0.93–1.13). Neither was significantly reduced. The reduction in myocardial infarction was a secondary outcome.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 25,871 participants: men aged 50 or older and women aged 55 or older Findings: Cancer: HR 0.96 (95% CI 0.88–1.06); major cardiovascular events: HR 0.97 (0.85–1.12). Neither was significantly reduced.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 49 trials involving 1,863 participants Findings: Supplementation combined with resistance training produced additional gains in strength and fat-free mass, among other measures.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 145 adults aged 70 or older with sarcopenia (440 planned) Findings: Leucine did not significantly improve the primary outcome.
Detailed records: 2 / Literature map: 10
Human research at a glance
Population: 201 adults aged 75 or older with moderate B12 deficiency but no anemia or neurological or cognitive symptoms. Findings: Blood B12 increased, but no significant benefits were found in primary neurological measures or cognition.
Detailed records: 1 / Literature map: 10
Human research at a glance
In 20,702 Chinese adults with hypertension, adding folic acid 0.8 mg/day to enalapril reduced first stroke occurrence over a median 4.5 years (2.7% versus 3.4%). The combination, baseline folate status and clinical population are essential to interpreting this positive result.
Detailed records: 1 / Literature map: 10
Human research at a glance
In a 12-week trial, 80 mg/day elemental iron reduced fatigue more than placebo in 198 menstruating women with low iron stores but without anemia. The finding supports assessing iron status when investigating fatigue; it is not a routine dose for people with adequate iron.
Detailed records: 1 / Literature map: 10
Human research at a glance
Vitamin C is essential for normal collagen synthesis and other functions. In a prevention trial involving 14,641 male physicians aged 50 or older, 500 mg/day for about 8 years did not reduce major cardiovascular events. Correcting deficiency and adding a supplement to an adequately nourished population are different questions.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 4,203 adults aged 50–85 at risk of progression to advanced age-related macular degeneration Findings: The primary analysis found no significant additional reduction in progression risk (HR 0.90, 98.7% CI 0.76–1.07). Replacement of beta-carotene is a separate question.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 4,837 adults aged 60–80 after myocardial infarction, continuing standard drug treatment. Findings: ALA: HR 0.91 (95% CI 0.78–1.05). No significant reduction in the primary outcome.
Detailed records: 1 / Literature map: 10
Sleep and stress
Human research at a glance
In a small crossover study, 3 g glycine before bed during 3 nights of restricted sleep improved selected next-day vigilance measures. Fatigue improved on day 1, not day 3. Only 7 healthy men were analyzed.
Detailed records: 1 / Literature map: 10
Metabolism and cellular function
Human research at a glance
In 24 women aged 55–70, taurine 1.5 g/day for 16 weeks increased the antioxidant enzyme SOD relative to control. This is a human biomarker finding; the study did not measure lifespan or long-term physical function.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 121 IBS patients randomized; 108 included in the intention-to-treat analysis Findings: Bloating and a score including gas improved. Overall severity, quality of life and some other measures did not improve significantly.
Detailed records: 1 / Literature map: 10
Human research at a glance
In adults with metabolic syndrome, 6 months of blueberry powder equivalent to 150 g of fresh blueberries daily improved vascular-function measures versus placebo. The primary insulin-resistance measure did not improve. This was a whole-food intervention, not a trial of isolated anthocyanins.
Detailed records: 1 / Literature map: 10
Human research at a glance
In 23 patients with stable coronary artery disease, Pycnogenol 200 mg/day for 8 weeks improved flow-mediated dilation, a measure of blood-vessel function, versus placebo. The estimated difference was 2.75 percentage points. This was added to standard treatment and did not test prevention of heart attacks.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 66 adults aged 65–90, mean age 71.7; approximately 76% women, all White. Findings: Between-group differences in the two primary outcomes were not significant. Improvements were reported in hand and leg muscle endurance at two months and in some blood markers.
Detailed records: 2 / Literature map: 10
Vision and cognition
Human research at a glance
A 2-year trial in 121 adults with cardiovascular risk and MRI-confirmed white matter lesions reported slower lesion progression with mixed tocotrienols 200 mg 2 times daily. The endpoint was an MRI measure, not improved memory or fewer dementia cases.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 22 otherwise healthy adults with overweight or obesity Findings: Resistin differed significantly between groups. Leptin did not reach significance, and adipsin did not differ.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 82 people with type 2 diabetes and nephropathy, taking an ACE inhibitor or ARB. Findings: Thiamine status improved, but urinary albumin and KIM-1 did not decrease significantly.
Detailed records: 1 / Literature map: 10
Human research at a glance
In the subgroup of 17 obese participants with poorly controlled type 2 diabetes, fasting glucose and HbA1c improved versus placebo. Across the broader poorly controlled group, fasting glucose improved but HbA1c did not differ significantly. These subgroup results should be interpreted with the analysis limitations.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: Analysis of 1,021 women with normal baseline liver enzymes from a trial involving 1,075 women Findings: Moderate or more severe liver test abnormalities occurred in 5.1% of the extract group. Odds ratio versus control: 7.0 (95% CI 2.4–20.3).
Detailed records: 1 / Literature map: 10
Metabolism and cellular function
Human research at a glance
Population: 67 pregnant women in Qatar; 43 followed through delivery. The planned sample was 640. Findings: No significant differences in incidence or maternal and neonatal outcomes. The authors judged the findings inconclusive because of insufficient power.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 30 adults without major psychiatric disorders Findings: Some sleep subscales differed from placebo. Results also included within-group changes and cognitive findings in subgroups.
Detailed records: 1 / Literature map: 10
Human research at a glance
A 28-day trial of standardized saffron extract (14 mg 2 times daily) reported better self-rated sleep quality and insomnia scores than placebo in 55 analyzed adults. Total sleep time and time to fall asleep did not show a significant between-group improvement.
Detailed records: 1 / Literature map: 10
Human research at a glance
In 100 older adults with age-associated memory impairment, 500 mg/day citicoline for 12 weeks improved secondary episodic and composite memory measures versus placebo after multiplicity correction. The primary spatial-memory outcome did not differ.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 40 Asian men and women aged 35–64 Findings: Improvements versus placebo were reported across several skin measures.
Detailed records: 1 / Literature map: 10
Human research at a glance
Specific collagen peptides (VERISOL, 2.5 g/day) reduced eye-wrinkle volume in a trial of 114 women aged 45–65 over 8 weeks. This finding concerns a tested preparation and skin measurement; it does not establish the same benefit for every collagen product.
Detailed records: 1 / Literature map: 10
Human research at a glance
A small IBS trial found improvements in selected digestive symptoms with a specific GOS mixture. Of 60 enrolled participants, 44 completed the study. The study lasted 12 weeks overall, with 4-week treatment periods; the tested mixture contained 48% GOS.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 37 adults with overweight or obesity Findings: Mean weight loss of approximately 2.8 kg and improved insulin resistance were reported in humans.
Detailed records: 1 / Literature map: 10
Human research at a glance
Population: 275 primary-care IBS patients aged 18–65 Findings: Responders were more common than with placebo: 57% versus 35% in month one, and 59% versus 41% in month two. Quality of life did not differ.
Detailed records: 1 / Literature map: 10
Metabolism and cellular function
Human research at a glance
Population: Study A: 36 people newly diagnosed with type 2 diabetes. Study B: 48 people with inadequately controlled blood glucose. Findings: Reductions in HbA1c and blood glucose were reported. Transient gastrointestinal symptoms were reported in 20 participants (34.5%) during the study.
Detailed records: 1 / Literature map: 10
Human research at a glance
A specific Curcuma longa extract reduced knee-pain scores versus placebo over 12 weeks in 70 people with knee osteoarthritis; the difference was 9.1 mm on the pain scale. MRI measures did not demonstrate structural joint improvement. Extract composition matters: this was not a trial of 1,000 mg pure curcumin.
Detailed records: 1 / Literature map: 10
Metabolism and cellular function
Thioctic acid; lipoic acid; R-lipoic acid; ALA (not alpha-linolenic acid)
Human research at a glance
Short trials in diabetic neuropathy report symptom relief; longer trials have not established a clear disease-modifying effect. In diabetes, pooled metabolic changes are generally small.
Detailed records: 3 / Literature map: 10
Metabolism and cellular function
GSH; reduced glutathione; liposomal glutathione; micellar glutathione
Human research at a glance
Some oral preparations increase measured glutathione, but results differ by duration, formulation and sampling compartment. Clinical benefits cannot be read directly from a blood or cell concentration.
Detailed records: 3 / Literature map: 10
Metabolism and cellular function
Arthrospira; Limnospira; spirulina biomass; blue-green algae
Human research at a glance
Meta-analyses suggest modest improvements in some cardiovascular risk markers, with variation between studies. Small exercise studies do not consistently show better performance.
Detailed records: 3 / Literature map: 10
Strength and exercise
Ophiocordyceps sinensis; Cordyceps sinensis; Cordyceps militaris; Cs-4; cultured mycelium
Human research at a glance
Small human studies report selected exercise or fatigue signals, but results depend on preparation and outcome. Evidence from a mushroom blend cannot establish the effect of Cordyceps alone.
Detailed records: 3 / Literature map: 10
Vitamins and minerals
Nicotinic acid; nicotinamide; niacinamide; vitamin B3; niacin equivalents
Human research at a glance
Vitamin B3 forms have different evidence. Nicotinamide 500 mg 2 times daily reduced the rate of new nonmelanoma skin cancers by 23% relative to placebo over 12 months in 386 people with repeated prior skin cancers. High-dose nicotinic acid did not add cardiovascular-event benefit to statin therapy in large trials.
Detailed records: 3 / Literature map: 10
Human research at a glance
Small trials of moringa leaf powder have produced different glucose findings. Recent syntheses do not establish a consistent, high-certainty cardiometabolic benefit.
Detailed records: 3 / Literature map: 10
Metabolism and cellular function
CGA; chlorogenic acids; caffeoylquinic acids; green coffee extract
Human research at a glance
Short trials suggest blood-pressure or weight changes with some preparations. A six-month trial of isolated chlorogenic acid in diabetes with fatty liver did not improve the main liver outcomes.
Detailed records: 3 / Literature map: 10
Metabolism and cellular function
HCA; hydroxycitrate; Garcinia gummi-gutta; Garcinia cambogia
Human research at a glance
Pooled weight differences are small and sensitive to study quality. Rare reports of serious liver injury require proportionate attention and are not excluded by normal average liver tests in short trials.
Detailed records: 3 / Literature map: 10
Human research at a glance
Small trials report changes in subjective fatigue or sleep, but stress-hormone findings are not consistent. Safety interpretation depends on dose, salt form and the completeness of adverse-event reporting.
Detailed records: 3 / Literature map: 10
Metabolism and cellular function
Trans-pterostilbene; dimethylated resveratrol; Pterocarpus marsupium extract
Human research at a glance
Human evidence is limited. One small trial found lower blood pressure but higher LDL cholesterol; combination studies cannot identify pterostilbene’s contribution. Greater exposure is not the same as greater clinical value.
Detailed records: 3 / Literature map: 7
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Selected studies make it easier to examine positive and negative findings and distinguish primary from secondary outcomes. Classic trials are included; this is not a systematic review of all recent literature. This selection alone does not rank ingredients or recommendations.
“Human intervention study” describes a design; “small exploratory study” describes scale or purpose. These are not certainty ratings such as S or A. Funding and conflicts are marked unverified when they could not be checked.
Read the editorial policyReader edition updated 2026-10-11: ingredient profiles, research questions and navigation. Individual study review dates remain as shown.
