Evidence-graded supplement library

Clear supplement answers, without the marketing claims

Each guide separates established uses from promising research, weak evidence and unanswered questions. Dosage, safety, interactions and different forms are explained in plain English.

Guidelines firstHuman trials prioritisedEvery benefit gradedNo product sponsorship

Published guides

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65 results

In-depth guideSupplementsGlucosamine for Osteoarthritis: Sulfate, HCl and SafetyCompare glucosamine sulfate and hydrochloride, conflicting knee osteoarthritis trials, guideline advice and warfarin safety before judging a product claim.Updated Sep 24, 20268 minute read

In-depth guideSupplementsGlycine: Sleep Evidence, Dose & SafetySee what human glycine research shows for sleep and healthy aging, why 3 g is a studied amount—not a universal dose—and how to read evidence and product labels.Updated Aug 30, 202616 minute read

In-depth guideSupplementsThiamine (Vitamin B1) SupplementsUnderstand thiamine nutrition, deficiency care and supplement claims. Compare B1 forms and see why correcting low thiamine differs from proving extra benefit.Updated Sep 10, 20265 minute read

In-depth guideSupplements2'-Fucosyllactose (2'-FL): Evidence, Safety & Doses StudiedWhat 2'-fucosyllactose is, what adult trials actually found, how pure 2'-FL differs from HMO mixtures, and what remains uncertain about benefits and safety.Updated Aug 24, 202612 minute read

In-depth guideSupplementsFenugreek Supplements: Food, Evidence and SafetySeparate fenugreek food use from supplements, review uncertain glucose and milk-supply claims, and understand pregnancy, allergy and low-blood-sugar concerns.Updated Sep 28, 20265 minute read

In-depth guideSupplementsBiotin SupplementsReview the evidence for biotin hair and nail supplements, understand mcg versus mg, and learn why the laboratory needs to know about biotin before blood tests.Updated Sep 8, 20265 minute read

In-depth guideSupplementsAcacia Fiber: Gut Evidence, Dose & SafetyUnderstand acacia fiber and gum arabic, bowel and glucose evidence, doses studied, gradual use, side effects and product-quality limits.Updated Sep 2, 202614 minute read

In-depth guideSupplementsAstaxanthin Supplements: Human Evidence and Product LimitsReview human astaxanthin evidence for skin and exercise, understand the difference between biomarkers and meaningful benefits, and see product and safety limits.Updated Sep 30, 20266 minute read

In-depth guideSupplementsBacopa monnieri: Memory Evidence, Studied Extracts and SafetyA careful guide to Bacopa monnieri and memory, covering human trials, standardised extracts, studied doses, gastrointestinal effects, interactions and product-quality limits.Updated Sep 5, 202616 minute read

In-depth guideSupplementsCholine BitartrateUnderstand choline bitartrate labels, nutritional needs and memory claims, with human study limits and a balanced explanation of TMAO and supplement safety.Updated Sep 8, 20265 minute read

In-depth guideSupplementsEvening Primrose Oil: Evidence, GLA and SafetyReview evening primrose seed oil and GLA, the negative oral eczema evidence, uncertain other benefits, and product and pregnancy safety limits.Updated Sep 28, 20265 minute read

In-depth guideSupplementsInositol for PCOS: what myo-inositol and D-chiro-inositol evidence supportsAn evidence-graded guide to myo-inositol and D-chiro-inositol for PCOS, including metabolic signals, fertility uncertainty, pregnancy boundaries, quality and safety.Updated Sep 3, 202624 minute read

In-depth guideSupplementsOmega-3 (EPA and DHA): Benefits, Dosage, Forms and EvidenceEPA and DHA guide comparing prescription omega-3 medicines with over-the-counter omega-3 supplements: benefits, dose, triglycerides, pregnancy and safety.Updated Aug 1, 202630 minute read

In-depth guideSupplementsPassionflower: Sleep Evidence and SafetyWhat small passionflower studies show about sleep and anxiety, why tea and extracts differ, and the key precautions around sedation, pregnancy and surgery.Updated Sep 22, 20265 minute read

In-depth guideSupplementsPeppermint Oil for IBS: Evidence and SafetyCompare enteric-coated peppermint oil evidence, mixed adult trials and the 2026 paediatric study. Learn about reflux, product differences and safety limits.Updated Sep 13, 20265 minute read

In-depth guideSupplementsProbiotics: Strains, Benefits, CFU & SafetyChoose probiotics by strain and purpose, not CFU alone. See evidence limits, label checks, storage, side effects and when live microbes need medical advice.Updated Aug 29, 202617 minute read

In-depth guideSupplementsVitamin B12 supplements: benefits, dosage, forms and blood testsAn evidence-based vitamin B12 guide covering deficiency, blood tests, doses, methylcobalamin versus cyanocobalamin, injections, interactions and who needs care.Updated Aug 9, 202625 minute read

Coming next

The next evidence guides in our research queue

These are previews, not finished guide links. Each card has a stable page anchor until its full research review is published.

Coming next

Psyllium

Cholesterol, constipation, glucose and how to take it

Research in progress Coming next

Ashwagandha

Stress, sleep, thyroid cautions and evidence limits

Research in progress Coming next

Calcium

Bone health, dietary intake, dosage and heart safety

Research in progress Coming next

Riboflavin (vitamin B2)

Migraine prevention, studied doses and safety

Research in progress Coming next

Melatonin

Sleep timing, jet lag, dosage and long-term uncertainty

Research in progress Coming next

Zinc

Deficiency, immune claims, dosage and copper balance

Research in progress

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See how LongevityMate grades evidence

Strong, moderate, limited and insufficient are not marketing labels. They reflect study quality, consistency, directness and how confidently the research applies to people.

Read our methodology