THE EVIDENCE
Understand the evidence.
THE EVIDENCE
What the research says the key ingredients in each formula do, in plain English, with the number that shows it.
Every finding comes from a published human study you can read yourself. Studies test single ingredients, not an apiece formula.
Build my formula Browse ingredientsTHE SHORT VERSION
What the research says, goal by goal.
Healthy aging
2× selenium absorbed, in the form we use
Your formula uses the selenium form that is absorbed about twice as well as selenite.*
Selenomethionine, the form we use, was about twice as well absorbed as selenite in a dose-ranging trial in a low-selenium area.
AStrongSelenium · Am J Clin Nutr 2005 · 120 people
Read the study : Effectiveness of selenium supplements in a low-selenium area of China. (opens PubMed in a new tab) See the Healthy aging formula
Immune support
3× blood vitamin D in a year
Vitamin D has a role in normal immune function, and a daily amount like yours raises blood levels.*
In a study of 163 women low in vitamin D, about 3,200 IU a day for a year nearly tripled blood vitamin D levels.
Studyabout 3,200 IU a day Your Immune support formula3,000 IU
AStrongVitamin D3 · Ann Intern Med 2012 · 163 women
Read the study : Dose response to vitamin D supplementation in postmenopausal women: a randomized trial. (opens PubMed in a new tab) See the Immune support formula
Skin health
−20% wrinkle volume around the eyes
Collagen peptides support skin hydration and elasticity.*
2.5 g a day of the collagen peptides we use reduced wrinkle volume around the eyes by about 20% in women 45 to 65.
Study2.5 g a day Your Skin health formula2.5 g
AStrongCollagen · Skin Pharmacol Physiol 2014 · 114 women
Read the study : Oral intake of specific bioactive collagen peptides reduces skin wrinkles and increases dermal matrix synthesis. (opens PubMed in a new tab) See the Skin health formula
Focus & memory
Better learning and delayed recall in 12 weeks
Bacopa supports normal learning and memory.*
In healthy older adults, 300 mg a day of a standardized bacopa extract improved learning and delayed recall over 12 weeks.
Study300 mg a day Your Focus & memory formula450 mg
BGoodBacopa extract · J Altern Complement Med 2010 · 98 adults
Read the study : Does Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial. (opens PubMed in a new tab) See the Focus & memory formula
Gut & digestion
Fewer hard stools after 4 weeks
Bacillus coagulans supports regular digestion.*
In healthy adults with infrequent bowel movements, about 2 billion spores a day of Bacillus coagulans increased bowel movements and reduced hard stools over 4 weeks.
Study2 billion spores a day Your Gut & digestion formula2 billion spores
AStrongBacillus coagulans · Benef Microbes 2025 · 144 adults
Read the study : Bacillus coagulans improves stool characteristics in healthy adults with infrequent bowel movements: a randomized, double-blind, placebo-controlled trial. (opens PubMed in a new tab) See the Gut & digestion formula
Relaxation
Better sleep, as people rated it
People who took L-theanine rated their sleep better.*
Across 18 pooled trials, L-theanine modestly improved how well people felt they slept and how quickly they felt they fell asleep. The trials included people with and without sleep problems.
AStrongL-theanine · Sleep Med Rev 2025 · 19 studies, 897 people
Read the study : The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis. (opens PubMed in a new tab) See the Relaxation formula
Stress & resilience
Lower cortisol, the body’s main stress hormone
Ashwagandha helps your body handle everyday stress.*
A review of 52 human studies of 26 plants and nutrients found ashwagandha’s effect on cortisol, the body’s main stress hormone, the most consistent. The review did not pool results.
BGoodAshwagandha extract · Nutr Neurosci 2022 · 52 plant studies
Read the study : Modulation of the hypothalamic-pituitary-adrenal (HPA) axis by plants and phytonutrients: a systematic review of human trials. (opens PubMed in a new tab) See the Stress & resilience formula
Muscle & recovery
+1 kg lean muscle with strength training
Creatine helps your muscles make quick energy for strength and power.*
In pooled trials, creatine with strength training added about 1 kg of lean muscle and trimmed body fat.
Studyabout 7 g a day for +1 kg, the authors’ estimate Your Muscle & recovery formula3 g
AStrongCreatine · J Strength Cond Res 2024 · 12 trials
Read the study : The Effect of Creatine Supplementation on Resistance Training-Based Changes to Body Composition: A Systematic Review and Meta-analysis. (opens PubMed in a new tab) See the Muscle & recovery formula
01 / 08
*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.
THE STUDIES BEHIND IT
The studies, by goal.
The findings above, and the other strong studies for each formula. Only grade A and B findings get a card.
How we grade a finding
- A
Strong. Pooled results from many trials, or one controlled trial of 100 or more people.
- B
Good. One controlled trial of 30 to 99 people.
- C
Early. Smaller studies, single-dose absorption tests, or small or mixed results. Listed, never featured.
In every formula
Vitamin D3, vitamin C, B vitamins, magnesium and zinc are in every apiece formula.
AStrong evidenceNearly 3× the blood vitamin D after a year
IngredientVitamin D3
See the ingredientIn a study of 163 women low in vitamin D, about 3,200 IU a day for a year nearly tripled blood vitamin D levels.
Studyabout 3,200 IU a day Your formula3,000 IU
Ann Intern Med · 2012 · Placebo-controlled trial · 163 women
Read the study : Dose response to vitamin D supplementation in postmenopausal women: a randomized trial. (opens PubMed in a new tab) AStrong evidenceBlood magnesium rises with the dose, then levels off near 300 mg
IngredientMagnesium bisglycinate
See the ingredientAcross 48 trials, blood magnesium rose with the amount taken and leveled off at about 300 mg a day.
J Nutr · 2016 · Meta-analysis · 48 trials, 2,131 people
Read the study : The Circulating Concentration and 24-h Urine Excretion of Magnesium Dose- and Time-Dependently Respond to Oral Magnesium Supplementation in a Meta-Analysis of Randomized Controlled Trials. (opens PubMed in a new tab)Mixed or early evidence (3) Grade C: not featured
These studies are small, short or had mixed results, so we don’t lead with them. They are listed so you can see everything we looked at.
Zinc bisglycinate. Absorbed about 43% better than zinc gluconate.
CEarlySingle-dose study in 12 women · Int J Vitam Nutr Res · 2007
Read the study : A bioavailability study comparing two oral formulations containing zinc (Zn bis-glycinate vs. Zn gluconate) (opens in a new tab)Vitamin C. Blood vitamin C rose with the amount taken and leveled off between 200 and 1,000 mg a day.
CEarly7 volunteers · Proc Natl Acad Sci U S A · 1996
Read the study : Vitamin C pharmacokinetics in healthy volunteers (opens in a new tab)Vitamin B12. The gut absorbed only about 1% of larger doses, which is why supplements carry more than the daily value.
CEarly9 adults, plus a pooled analysis · Nutrients · 2024
Read the study : The Oral Bioavailability of Vitamin B(12) at Different Doses in Healthy Indian Adults. (opens in a new tab)
Healthy aging
The 2 strongest findings for ingredients in this formula.
See the Healthy aging formula AStrong evidenceAbout twice as well absorbed as selenite
IngredientSelenium
See the ingredientSelenomethionine, the form we use, was about twice as well absorbed as selenite in a dose-ranging trial in a low-selenium area.
Am J Clin Nutr · 2005 · Randomized trial · 120 people
Read the study : Effectiveness of selenium supplements in a low-selenium area of China. (opens PubMed in a new tab) AStrong evidenceMore glutathione, the body’s main antioxidant
IngredientNAC
See the ingredientIn pooled trials, NAC raised glutathione, the body’s main antioxidant, and reduced soreness after exercise.
J Cell Mol Med · 2024 · Meta-analysis · 20 studies
Read the study : The impact of N-acetylcysteine on lactate, biomarkers of oxidative stress, immune response, and muscle damage: A systematic review and meta-analysis. (opens PubMed in a new tab)Mixed or early evidence (1) Grade C: not featured
These studies are small, short or had mixed results, so we don’t lead with them. They are listed so you can see everything we looked at.
CoQ10. 300 mg a day reduced fatigue during a long cycling test.
CEarly17 people · Nutrition · 2008
Read the study : Antifatigue effects of coenzyme Q10 during physical fatigue. (opens in a new tab)
Immune support
Neither study measured immune function itself: one measured fatigue, the other glutathione, the body’s main antioxidant. Vitamin D’s role in immune function is in every formula.
See the Immune support formula AStrong evidenceLess fatigue and more vigor across 16 trials
IngredientBeta-glucan
See the ingredientAcross trials in healthy people, beta-glucans reduced fatigue and improved vigor and mood.
Eur J Clin Nutr · 2025 · Meta-analysis · 16 trials, 1,449 people
Read the study : Effects of β-glucans on fatigue: a systematic review and meta-analysis. (opens PubMed in a new tab) AStrong evidenceMore glutathione, the body’s main antioxidant
IngredientNAC
See the ingredientIn pooled trials, NAC raised glutathione, the body’s main antioxidant, and reduced soreness after exercise.
J Cell Mol Med · 2024 · Meta-analysis · 20 studies
Read the study : The impact of N-acetylcysteine on lactate, biomarkers of oxidative stress, immune response, and muscle damage: A systematic review and meta-analysis. (opens PubMed in a new tab)Skin health
The 2 strongest findings for ingredients in this formula.
See the Skin health formula AStrong evidenceAbout 20% less wrinkle volume around the eyes
IngredientCollagen
See the ingredient2.5 g a day of the collagen peptides we use reduced wrinkle volume around the eyes by about 20% in women 45 to 65.
Study2.5 g a day Your Skin health formula2.5 g
Skin Pharmacol Physiol · 2014 · Placebo-controlled trial · 114 women
Read the study : Oral intake of specific bioactive collagen peptides reduces skin wrinkles and increases dermal matrix synthesis. (opens PubMed in a new tab) AStrong evidenceBetter skin hydration, elasticity and fine lines
IngredientHyaluronic acid
See the ingredientIn a placebo-controlled trial, 120 mg a day of oral hyaluronic acid improved skin hydration, elasticity and fine lines around the eyes.
Study120 mg a day Your Skin health formula121 mg
Sci Rep · 2025 · Placebo-controlled trial · 150 adults
Read the study : Oral sodium hyaluronate improves skin hydration, barrier function and signs of aging: a randomized, double-blind, placebo-controlled trial in 150 healthy adults. (opens PubMed in a new tab)Energy & vitality
See the Energy & vitality formulaWe don’t feature a study for this formula’s ingredients yet. Each ingredient’s NIH reference is on the formula page, and every formula includes the .
Mixed or early evidence (2) Grade C: not featured
These studies are small, short or had mixed results, so we don’t lead with them. They are listed so you can see everything we looked at.
Natural caffeine with L-theanine. 40 mg of caffeine taken with 97 mg of L-theanine improved alertness and task-switching accuracy. The Energy formula has 100 mg of caffeine and no L-theanine.
CEarlyA different mix from our formula, 44 adults · Nutr Neurosci · 2010
Read the study : The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. (opens in a new tab)Ginseng extract. 400 mg improved calmness and mental arithmetic for a few hours. 200 mg, the amount in the Energy formula, slowed mental arithmetic. Repeated doses added no benefit.
CEarlyMixed results by dose, 30 adults · Hum Psychopharmacol · 2010
Read the study : Panax ginseng improves aspects of working memory performance and subjective ratings of calmness in healthy young adults. (opens in a new tab)
Focus & memory
The strongest finding for ingredients in this formula.
See the Focus & memory formula BGood evidenceBetter learning and recall over 12 weeks
IngredientBacopa extract
See the ingredientIn healthy older adults, 300 mg a day of a standardized bacopa extract improved learning and delayed recall over 12 weeks.
Study300 mg a day Your Focus & memory formula450 mg
J Altern Complement Med · 2010 · Placebo-controlled trial · 98 adults
Read the study : Does Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial. (opens PubMed in a new tab)Gut & digestion
The strongest finding for ingredients in this formula.
See the Gut & digestion formula AStrong evidenceMore frequent bowel movements and softer stools
IngredientBacillus coagulans
See the ingredientIn healthy adults with infrequent bowel movements, about 2 billion spores a day of Bacillus coagulans increased bowel movements and reduced hard stools over 4 weeks.
Study2 billion spores a day Your Gut & digestion formula2 billion spores
Benef Microbes · 2025 · Placebo-controlled trial · 144 adults
Read the study : Bacillus coagulans improves stool characteristics in healthy adults with infrequent bowel movements: a randomized, double-blind, placebo-controlled trial. (opens PubMed in a new tab)Relaxation
The strongest finding for ingredients in this formula.
See the Relaxation formula AStrong evidenceBetter sleep, as people rated it, across pooled trials
IngredientL-theanine
See the ingredientAcross 18 pooled trials, L-theanine modestly improved how well people felt they slept and how quickly they felt they fell asleep. The trials included people with and without sleep problems.
Sleep Med Rev · 2025 · Meta-analysis · 19 studies, 897 people
Read the study : The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis. (opens PubMed in a new tab)Mixed or early evidence (2) Grade C: not featured
These studies are small, short or had mixed results, so we don’t lead with them. They are listed so you can see everything we looked at.
Magnesium bisglycinate. A self-reported sleep-symptom scale showed a small benefit over placebo; sleep was not measured objectively.
CEarlySmall effect, 155 adults, 4 weeks · Nat Sci Sleep · 2025
Read the study : Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial (opens in a new tab)L-theanine. Selected sleep subscales improved, while the total sleep score did not differ from placebo.
CEarlyMixed results, 30 adults · Nutrients · 2019
Read the study : Effects of L-theanine administration on stress-related symptoms and cognitive functions in healthy adults: a randomized controlled trial (opens in a new tab)
Stress & resilience
The strongest finding for ingredients in this formula.
See the Stress & resilience formula BGood evidenceLower cortisol, the body’s main stress hormone
IngredientAshwagandha extract
See the ingredientA review of 52 human studies of 26 plants and nutrients found ashwagandha’s effect on cortisol, the body’s main stress hormone, the most consistent. The review did not pool results.
Nutr Neurosci · 2022 · Systematic review · 52 plant studies
Read the study : Modulation of the hypothalamic-pituitary-adrenal (HPA) axis by plants and phytonutrients: a systematic review of human trials. (opens PubMed in a new tab)Muscle & recovery
The strongest finding for ingredients in this formula.
See the Muscle & recovery formula AStrong evidenceAbout 1 kg more lean muscle with strength training
IngredientCreatine
See the ingredientIn pooled trials, creatine with strength training added about 1 kg of lean muscle and trimmed body fat.
Studyabout 7 g a day for +1 kg, the authors’ estimate Your Muscle & recovery formula3 g
J Strength Cond Res · 2024 · Meta-analysis · 12 trials
Read the study : The Effect of Creatine Supplementation on Resistance Training-Based Changes to Body Composition: A Systematic Review and Meta-analysis. (opens PubMed in a new tab)Heart & metabolic health
See the Heart & metabolic health formulaWe don’t feature a study for this formula’s ingredients yet. Each ingredient’s NIH reference is on the formula page, and every formula includes the .
Research on an ingredient is not a clinical study of an apiece formula. Study amounts describe the research and are not recommendations. Evidence reviewed October 2026.
MANUFACTURING QUALITY
How we test your formula.
Studies tell you what an ingredient can do. Testing checks that what’s in the bottle is what the label says.
Source
Qualified suppliers
Supplier qualification, source records, ingredient specifications and allergen information for every material.
Check
Tested before use
Every material is checked before it is used for:
- Identity
- Potency
- Microbes
- Heavy metals
Blend
Made to your formula
Your formula is weighed, blended and encapsulated to its specified composition, made to order.
Record
Traceable batches
Batch records and finished-product potency testing keep every bottle traceable.
Made by our manufacturing partner in US facilities that follow current Good Manufacturing Practice (cGMP) for dietary supplements.
These are our partner’s documented manufacturing practices. Batch certificates and formula-specific test results are not published on this page.
Read the quality standardsReady to build yours?
Every ingredient in your formula shows its research, or tells you plainly when we don’t have a strong study yet.
Build my formula Browse ingredients*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 general information, not medical advice. Check with your doctor or pharmacist before starting a supplement, especially if you take medication, are pregnant or nursing, or have a health condition. Updated 2026-11-02.