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VVaunted

Evidence

Grades per claim, with the reasoning attached

An ingredient can have strong evidence for one outcome and thin evidence for another, so we grade each ingredient–outcome pair separately. Every grade carries a rationale, sources, limitations and a review date.

Scale

How the grades are defined

S
Very strong, consistent human evidence — typically multiple high-quality randomized trials and/or high-quality systematic reviews.
A
Strong human evidence with generally consistent results.
B
Moderate human evidence; promising, with meaningful limitations or inconsistency.
C
Limited or preliminary human evidence.
D
Primarily mechanistic, animal, observational or otherwise weak evidence.
F
Adequate evidence suggests the marketed claim is unsupported, ineffective or misleading.

Searchable library

Search an ingredient, an outcome, or both

Try creatine, creatine sleep, creatine strength, cholesterol or stress. Same ingredient, different outcome, different grade — that is the point.

8 of 8 entries shown

Creatine monohydrate

for Strength and power performance

S

Large body of randomized trials and multiple systematic reviews report consistent gains in high-intensity performance when combined with resistance training.

Limitations: Effect sizes vary with training status and baseline muscle creatine.

Key references

  • Kreider RB et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation. J Int Soc Sports Nutr, 2017.
  • Chilibeck PD et al. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access J Sports Med, 2017.

Reviewed 2026-06-01

Creatine monohydrate

for Cognitive performance

C

Some trials suggest benefit under sleep deprivation or in vegetarians, but results across healthy rested adults are inconsistent.

Limitations: Small samples, heterogeneous cognitive endpoints, short durations.

Key references

  • Avgerinos KI et al. Effects of creatine supplementation on cognitive function of healthy individuals: a systematic review of randomized controlled trials. Exp Gerontol, 2018.
  • Rae C et al. Oral creatine monohydrate supplementation improves brain performance: a double-blind, placebo-controlled, cross-over trial. Proc Biol Sci, 2003.

Reviewed 2026-06-01

Magnesium

for Subjective sleep quality

C

Modest improvements reported in small trials, often in older adults or people with low intake.

Limitations: Few well-powered trials; forms and doses differ widely.

Key references

  • Abbasi B et al. The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial. J Res Med Sci, 2012.
  • Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a systematic review and meta-analysis. BMC Complement Med Ther, 2021.

Reviewed 2026-05-18

EPA/DHA

for Triglyceride reduction

A

Dose-dependent triglyceride lowering is reproducible across trials, with larger effects at higher intakes.

Limitations: Effects on cardiovascular events depend on dose, formulation and population.

Key references

  • Skulas-Ray AC et al. Omega-3 fatty acids for the management of hypertriglyceridemia: a science advisory from the American Heart Association. Circulation, 2019.
  • Bernstein AM et al. A meta-analysis shows that docosahexaenoic acid from algal oil reduces serum triglycerides. J Nutr, 2012.

Reviewed 2026-05-22

Ashwagandha

for Perceived stress

B

Several randomized trials report reductions in stress scales over 8–12 weeks.

Limitations: Many trials are small, industry-funded, and use different extracts and scales.

Key references

  • Chandrasekhar K et al. 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.
  • Della Porta M et al. Withania somnifera (ashwagandha) and stress: a systematic review of randomized controlled trials. Nutrients, 2023.

Reviewed 2026-04-30

Psyllium husk

for LDL cholesterol reduction

A

Consistent modest LDL reduction across controlled feeding and supplement trials.

Limitations: Requires sustained daily intake; adherence drives the effect.

Key references

  • Jovanovski E et al. Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr, 2018.
  • Wei ZH et al. Time- and dose-dependent effect of psyllium on serum lipids in mild-to-moderate hypercholesterolemia: a meta-analysis of controlled clinical trials. Eur J Clin Nutr, 2009.

Reviewed 2026-05-02

Berberine

for Fasting glucose and HbA1c

B

Meta-analyses of mostly small trials report glycemic improvement, several conducted in one region with variable methodology.

Limitations: Known drug interactions, GI tolerability, and quality concerns in the trial literature.

Key references

  • Lan J et al. Meta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension. J Ethnopharmacol, 2015.
  • Guo J et al. Effect of berberine on glycaemic control in patients with type 2 diabetes: a systematic review and meta-analysis. Front Pharmacol, 2021.

Reviewed 2026-04-12

Collagen peptides

for Reversing skin aging

D

Marketed claims outrun the evidence; available trials are short, small and frequently manufacturer-funded.

Limitations: Subjective endpoints and high risk of bias.

Key references

  • de Miranda RB et al. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. Int J Dermatol, 2021.
  • Pu SY et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients, 2023.

Reviewed 2026-03-28

Grades are editorial and are maintained independently of any commercial relationship. Commission never influences a grade.

Health topics

Start from a topic instead of a product

Shop by goal

  • Sleep

    Duration, efficiency and timing, and what actually moves them.

    Key biomarkers: HRV, Resting heart rate, Ferritin

  • Cardiovascular health

    Lipids, blood pressure and inflammation, and how they respond to change.

    Key biomarkers: ApoB, LDL-C, Lp(a), hs-CRP

  • Metabolic health

    Glucose regulation, insulin sensitivity and body composition.

    Key biomarkers: HbA1c, Fasting insulin, Triglycerides

  • Hormone health

    What is measurable, what varies by time of day, and what needs a clinician.

    Key biomarkers: Total testosterone, SHBG, TSH, Estradiol

  • Cognition

    What is measurable at home versus what needs formal testing.

    Key biomarkers: Homocysteine, Vitamin B12, Vitamin D, 25-OH

  • Gut health

    Fiber, tolerance and the limits of current consumer testing.

    Key biomarkers: hs-CRP, Ferritin