Supplements

1. Supplementswell supported · human dataAdded 5 September 2026

   Probiotics barely shift immune markers in healthy adults

   A systematic review of 18 randomised controlled trials covering 819 healthy adults concluded that probiotic supplements have only a limited effect on circulating immune and inflammatory markers; 8 trials reported some changes, but the evidence was too inconsistent to size any effect.

   ⚠What it shows: A solid basis for scepticism: this sweep of all the trials in healthy adults, 819 people across 18 studies, found the results so inconsistent that they could not even be combined into a single estimate. It says nothing about people with illness, where probiotics may behave differently.Systematic review · J Acad Nutr Diet

   Full breakdown →Probiotics guide →Probiotic Supplementation Has a Limited Effect on Circulating Immune and Inflammatory Markers in Healthy Adults: A Systematic Review of Randomized Controlled Trials. J Acad Nutr Diet 2020
2. Supplementspreliminary · human dataAdded 3 September 2026

   Vitamin C lowered blood pressure and long-term blood sugar in diabetes trials

   Pooled results from 28 trials in 1,574 adults with type 2 diabetes linked vitamin C supplementation to a 6.27 mmHg drop in systolic blood pressure and a 0.54% fall in HbA1c, but most trials were short and small, and the authors say it cannot yet be recommended as a therapy.

   ⚠What it shows: A lead, not a therapy: results pooled from 28 trials in 1,574 adults, but most ran under six months with fewer than 100 people each, and the blood sugar finding rests on very low certainty evidence.Meta-analysis · Diabetes Care

   Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →Effects of Vitamin C Supplementation on Glycemic Control and Cardiovascular Risk Factors in People With Type 2 Diabetes: A GRADE-Assessed Systematic Review and Meta-analysis of Randomized Controlled Trials. Diabetes Care 2021
3. Supplementspreliminary · human dataAdded 3 September 2026

   Fish oil grew muscle without a single workout in most trials that checked

   A systematic review of seven randomised trials in 192 sedentary or immobilised people found that five of the six studies measuring muscle size reported higher muscle volume and mass with omega-3 supplementation and no training at all, and both studies measuring muscle protein synthesis found a higher rate.

   ⚠What it shows: Early and small: a sweep of seven trials covering just 192 sedentary or immobilised people, so nobody knows whether the effect adds anything for people who actually train.Systematic review · Crit Rev Food Sci Nutr

   Full breakdown →Muscle protein synthesis explained →Protein Intake Calculator →Muscle hypertrophy induced by N-3 PUFA supplementation in absence of exercise: a systematic review of randomized controlled trials. Crit Rev Food Sci Nutr 2023
4. Supplementspreliminary · human dataAdded 2 September 2026

   Beetroot shows promise for muscle force in combat sports

   A systematic review of nine randomised placebo-controlled trials found that beetroot supplementation may improve oxidative metabolism and muscle force production in combat sports athletes, though the effects appear to depend on the population, intake duration, muscle group and exercise type.

   ⚠What it shows: Promising but thin: a sweep of all the studies turned up just nine trials, most testing a one-off dose, with almost no data in women. Treat this as a maybe rather than a proven edge.Systematic review · Nutrients

   Full breakdown →Beetroot juice guide →Does Beetroot Supplementation Improve Performance in Combat Sports Athletes? A Systematic Review of Randomized Controlled Trials. Nutrients 2023
5. Supplementswell supported · human dataAdded 2 September 2026

   L-arginine barely touches cholesterol or inflammation

   Pooled across 17 randomised trials, L-arginine supplementation produced only a borderline reduction in triglycerides of 6.03 mg/dl and had no significant effect on LDL cholesterol, total cholesterol, HDL cholesterol or the inflammatory markers CRP and TNFα.

   ⚠What it shows: Trust the null here: results pooled from 17 trials showed nothing beyond a small triglyceride dip that only just reached significance, so any everyday benefit is likely trivial.Meta-analysis · Pharmacol Res

   Full breakdown →ApoB explained →Effect of L-Arginine supplementation on lipid profiles and inflammatory markers: A systematic review and meta-analysis of randomized controlled trials. Pharmacol Res 2019
6. Supplementswell supported · human dataAdded 2 September 2026

   EPA and DHA are not interchangeable: one lowers LDL, one raises it

   In a pooled analysis of 33 randomised trials, both EPA and DHA lowered triglycerides, but EPA also reduced total and LDL cholesterol while DHA raised total cholesterol, LDL and HDL. DHA also increased insulin levels compared with EPA.

   ⚠What it shows: One of the bigger pooled datasets on this question, drawing on 33 trials of purified EPA or DHA, though the trials disagreed on the size of each shift and what the opposing cholesterol changes mean for health is not settled.Meta-analysis · Clin Nutr

   Full breakdown →Metabolic syndrome explained →Effects of dietary eicosapentaenoic acid and docosahexaenoic acid supplementation on metabolic syndrome: A systematic review and meta-analysis of data from 33 randomized controlled trials. Clin Nutr 2021
7. Supplementspreliminary · human dataAdded 31 August 2026

   Probiotics made older adults walk faster, and that result held up

   In pooled trials of older adults, probiotic supplementation improved handgrip strength by 2.50 kg and gait speed by 0.10 m/s, but only the walking speed gain held up when the researchers stress-tested the numbers.

   ⚠What it shows: Promising but thin: only 8 trials made the review and just 4 fed the pooled analysis, and when the least robust data were removed the grip strength benefit vanished. Treat the walking speed gain as the sturdiest finding here, not the headline strength number.Meta-analysis · Nutr Rev

   Full breakdown →Sarcopenia explained →Effects of Probiotics, Prebiotics, and Synbiotics on Sarcopenia Parameters in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutr Rev 2025
8. Supplementswell supported · human dataAdded 31 August 2026

   Berberine trimmed waistlines but left the scale unmoved

   Across 10 trials, berberine supplementation was associated with small reductions in body mass index of 0.29 kg/m2 and in waist circumference of 2.75 cm, but no significant change in body weight.

   ⚠What it shows: Real but tiny: results pooled from 10 trials, and the changes are small enough that most people would not notice them on a tape measure over a normal supplement run. Body weight itself did not shift, and earlier individual trials had disagreed, which is what prompted the pooling in the first place.Meta-analysis · Complement Ther Clin Pract

   Full breakdown →Visceral fat explained →Body Fat Calculator →The effect of berberine supplementation on obesity indices: A dose- response meta-analysis and systematic review of randomized controlled trials. Complement Ther Clin Pract 2020
9. Supplementswell supported · human dataAdded 30 August 2026

   Capsinoid supplements failed to shift weight, waistlines or body fat

   Pooled results from 13 trials in 838 people found capsinoid supplements had no significant effect on body weight, BMI, waist circumference, fat mass, fat-free mass, visceral fat or body fat percentage. A modest weight reduction appeared only in overweight participants in trials lasting 12 weeks or longer.

   ⚠What it shows: Strong enough to doubt the fat-burner marketing: results pooled from 13 trials in 838 people found nothing across eight separate body measures. The hint of weight loss in overweight people on longer courses came from a smaller slice of the data, which is a weaker kind of evidence, and the authors say it needs confirming.Meta-analysis · Clin Nutr ESPEN

   Full breakdown →Energy balance explained →Calorie Deficit Calculator →The effects of capsinoids supplementation on body composition and anthropometric measures: A systematic review and dose-response meta-analysis of randomized controlled trials. Clin Nutr ESPEN 2022
10. Supplementswell supported · human dataAdded 30 August 2026

    Omega-3 left insulin sensitivity exactly where it found it

    A meta-analysis of 11 randomised trials in 618 people found omega-3 supplementation had no effect on insulin sensitivity compared with placebo. A small significant improvement appeared only in the subgroup of trials using one particular measurement method.

    ⚠What it shows: A fairly firm null for this specific question: results pooled from 11 trials in 618 people showed no change in insulin sensitivity versus placebo. One slice of trials using a single measurement method did show a small benefit, and the search only runs to October 2010, so later trials are not counted here.Meta-analysis · Clin Nutr

    Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →Omega-3 polyunsaturated fatty acid and insulin sensitivity: a meta-analysis of randomized controlled trials. Clin Nutr 2011
11. Supplementswell supported · human dataAdded 29 August 2026

    Creatine plus lifting builds more ageing muscle than lifting alone

    Meta-analyses indicate that combining creatine supplementation with resistance training improves ageing muscle mass and upper body strength beyond resistance training alone, and creatine also shows promise for bone mineral density and indices of bone biology.

    ⚠What it shows: Reasonably solid for muscle and upper body strength: the conclusion rests on pooled trials of creatine combined with resistance training in the context of ageing. The bone findings are promising rather than proven, and the abstract does not report how large the added benefits are.Meta-analysis · Endocrine

    Full breakdown →Creatine monohydrate guide →Creatine Calculator →Creatine supplementation and aging musculoskeletal health. Endocrine 2014
12. Supplementswell supported · human dataAdded 28 August 2026

    Pomegranate trims blood pressure and cholesterol, but the effects are small

    Pomegranate supplementation modestly reduced body weight, BMI, systolic and diastolic blood pressure, fasting glucose and total cholesterol, and raised HDL, across 53 randomised trials in 2306 people; LDL, triglycerides, HbA1c, waist measures and insulin resistance did not change.

    ⚠What it shows: Real but small: results pooled from 53 trials in 2306 people show statistically clear yet modest shifts, and several key markers, including LDL and triglycerides, did not move at all. The authors call for longer and larger trials before firm conclusions.Meta-analysis · Nutr Metab Cardiovasc Dis

    Full breakdown →Metabolic syndrome explained →Heart Age Calculator →Impacts of supplementation with pomegranate on cardiometabolic risk factors: A systematic review and dose-response meta-analysis. Nutr Metab Cardiovasc Dis 2025
13. Supplementswell supported · human dataAdded 28 August 2026

    CoQ10 shifts blood sugar and triglycerides in type 2 diabetes, not cholesterol

    In people with prediabetes or type 2 diabetes, CoQ10 supplementation significantly reduced triglycerides, fasting blood sugar, HbA1c, insulin resistance and the inflammation marker C-reactive protein, and raised HDL, across 20 randomised trials; total cholesterol, LDL and blood pressure did not change.

    ⚠What it shows: Encouraging but not the final word: results pooled from 20 trials in people with prediabetes or type 2 diabetes, and the trials disagreed with each other on how big the benefits were. The authors want longer studies across a range of doses before firm conclusions.Meta-analysis · BMC Pharmacol Toxicol

    Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →The effect of CoQ10 supplementation on cardiovascular risk factors in patients with prediabetes and type 2 diabetes mellitus: a grade-assessed systematic review and dose-response meta-analysis. BMC Pharmacol Toxicol 2026
14. Supplementswell supported · human dataAdded 28 August 2026

    Green coffee extract lowers blood sugar so little you would never notice

    A meta-analysis of ten randomised trials found green coffee bean extract lowered fasting blood sugar by 1.791 mg/dl on average, a statistically significant but very small change. Insulin did not improve overall, and only fell significantly in trials using doses of at least 400 mg per day.

    ⚠What it shows: Real but trivial: pooled from ten trials, the blood sugar drop was under two points, far too small for anyone to feel. On insulin the trials disagreed sharply, and the promising result came only from a subgroup taking at least 400 mg a day.Meta-analysis · Phytother Res

    Full breakdown →Insulin sensitivity explained →The influence of green coffee bean extract supplementation on blood glucose levels: A systematic review and dose-response meta-analysis of randomized controlled trials. Phytother Res 2020
15. Supplementspreliminary · human dataAdded 27 August 2026

    Curcumin nudged up adiponectin across six pooled trials

    Curcumin supplementation significantly increased circulating adiponectin compared with placebo in a pooled analysis of 6 randomised trials covering 652 adults. The effect appeared larger in trials lasting 10 weeks or less.

    ⚠What it shows: Promising but far from settled: results pooled from just 6 trials in 652 adults, and the authors themselves say more studies are needed before firm conclusions. Whether a higher adiponectin reading translates into any real health benefit was not tested here.Meta-analysis · Diabetes Metab Syndr

    Full breakdown →Curcumin guide →The effect of curcumin supplementation on circulating adiponectin: A systematic review and meta-analysis of randomized controlled trials. Diabetes Metab Syndr 2019
16. Supplementspreliminary · human dataAdded 27 August 2026

    Brain supplement N-PEP-12 shows hints, not proof, on attention

    In a randomised placebo-controlled trial of 276 adults aged 50 to 75 with subjective cognitive complaints, N-PEP-12 was associated with time-dependent improvements in attention across 180 days, with exploratory gains at 90 days, but there was no significant overall difference between treatment arms.

    ⚠What it shows: A weak signal so far: one trial in 276 adults aged 50 to 75 with self-reported memory gripes found no overall difference between the supplement and placebo, and the specific improvements came from exploratory comparisons that still need confirming.RCT · Nutrients

    Full breakdown →Impact of N-PEP-12 Supplementation on Attentional Performance and Mental Wellbeing in Healthy Adults with Subjective Cognitive Complaints: A Randomized, Placebo-Controlled Trial. Nutrients 2026
17. Supplementswell supported · human dataAdded 27 August 2026

    Whey nudges triglycerides but leaves cholesterol alone

    Pooling 13 randomised trials, whey protein supplementation lowered circulating triglycerides by a modest 0.11 mmol/l but had no effect on total cholesterol, LDL cholesterol or HDL cholesterol.

    ⚠What it shows: Solid as far as it goes: results pooled from 13 trials found only a small triglyceride dip and nothing else moved, and even that dip vanished in leaner people, at lower doses, or when participants were also exercising or cutting calories. One author works for a dairy company, so keep that in view when weighing the framing.Meta-analysis · Eur J Clin Nutr

    Full breakdown →Whey protein guide →Protein Intake Calculator →Effect of whey protein on blood lipid profiles: a meta-analysis of randomized controlled trials. Eur J Clin Nutr 2016
18. Supplementspreliminary · human dataAdded 25 August 2026

    Rhodiola may make hard sessions feel easier, but the evidence is shaky

    A review of 13 randomised trials in 263 healthy adults suggests Rhodiola rosea taken acutely may improve endurance performance and lower perceived exertion, while chronic use may help anaerobic performance and muscle damage. Most included studies carried an unclear or high risk of bias.

    ⚠What it shows: Encouraging but far from settled: a sweep of all the studies on this found 13 trials covering 263 healthy adults, and most carried an unclear or high risk of bias. Doses and exercise tests varied so much that no single benefit is nailed down yet.Systematic review · Phytother Res

    Full breakdown →Rhodiola rosea guide →Rhodiola rosea supplementation on sports performance: A systematic review of randomized controlled trials. Phytother Res 2023
19. Supplementspreliminary · human dataAdded 24 August 2026

    Endurance supplements that worked for older women flopped in older men

    A systematic review of endurance exercise in older adults found caffeine, and protein combined with beta-alanine, showed performance benefits in both sexes. Sodium bicarbonate and HMB looked favourable in older women, while older men saw no benefit from sodium bicarbonate or ubiquinone.

    ⚠What it shows: Early signals only: a sweep of all the studies on this turned up just 8 trials in older adults, too few and too varied to pool into a single estimate, so the sex differences here are hints rather than firm conclusions. The authors themselves say supplement use should be matched to the individual.Systematic review · Int J Environ Res Public Health

    Full breakdown →Caffeine guide →Caffeine Half-Life Calculator →Effect of Supplements on Endurance Exercise in the Older Population: Systematic Review. Int J Environ Res Public Health 2020
20. Supplementswell supported · human dataAdded 24 August 2026

    Quercetin boosts endurance, but only by about 2%

    A meta-analysis of 11 trials in 254 people found quercetin supplementation improved endurance capacity, covering VO2max and endurance performance, by roughly 2% over placebo. The authors rate the effect as between trivial and small.

    ⚠What it shows: About as settled as supplement evidence gets: results pooled from 11 trials in 254 people agree the benefit exists and agree it is tiny. Typical study courses ran around 11 days at 1000 mg per day, and neither fitness level nor blood quercetin levels changed the result.Meta-analysis · Med Sci Sports Exerc

    Full breakdown →VO₂max explained →VO2max Calculator →Quercetin and endurance exercise capacity: a systematic review and meta-analysis. Med Sci Sports Exerc 2011
21. Supplementspreliminary · human dataAdded 23 August 2026

    Vitamin D pills left the growth factor IGF-1 untouched

    Vitamin D supplementation produced no significant change in IGF-1, a growth factor tied to muscle, bone and ageing, in a meta-analysis of six randomised trials totalling 773 participants.

    ⚠What it shows: A fair verdict from results pooled across six trials with 773 people: no meaningful change in IGF-1 overall, and none in any subgroup. The trials disagreed with each other considerably, so a small effect in specific groups cannot be entirely ruled out.Meta-analysis · Complement Ther Med

    Full breakdown →Vitamin D guide →The effect of vitamin D supplementation on insulin-like growth factor-1: A systematic review and meta-analysis of randomized controlled trials. Complement Ther Med 2020
22. Supplementspreliminary · human dataAdded 23 August 2026

    Peppermint oil lowered blood pressure within 20 days

    Twice-daily peppermint oil supplementation, 100 μL per day, lowered systolic blood pressure by 8.48 mmHg relative to placebo after 20 days in a randomised trial of 40 adults with pre-hypertension and stage 1 hypertension. Readings fell from 130.05 to 121.97 mmHg in the peppermint group while the placebo group stayed flat.

    ⚠What it shows: Encouraging but far from settled: one 20-day trial in just 40 people with mildly raised blood pressure, run by a single research group. It needs repeating in bigger groups, and for longer, before peppermint earns a place alongside proven blood pressure care.RCT · PLoS One

    Full breakdown →Blood pressure explained →Heart Age Calculator →Effects of peppermint (Mentha x piperita L.) oil on cardiometabolic outcomes in patients with pre- and stage 1 hypertension: A placebo randomized controlled trial. PLoS One 2026
23. Supplementspreliminary · human dataAdded 23 August 2026

    Vitamin D was linked to sharper cognition, but only at 5000 IU and up

    In a snapshot study of 54 older adults with mild cognitive impairment and disturbed sleep, those taking 5000 IU or more of vitamin D daily scored higher on the MoCA cognitive test than people taking none. Lower doses showed no significant link, and D3 users did no better than D2 users.

    ⚠What it shows: Treat this as a lead, not an answer: a one-off snapshot of 54 people whose supplement use was self-reported, so it cannot show the vitamin caused the better scores. Being overweight also tracked with higher scores here, a hint that things other than the pill may be driving the pattern.Study · Sleep Med

    Full breakdown →Vitamin D guide →Sleep Calculator →Vitamin D supplement intake is associated with better cognition in persons with sleep disturbance and mild cognitive impairment. Sleep Med 2026
24. Supplementswell supported · human dataAdded 23 August 2026

    Nitrate supplements stretch endurance but leave race times untouched

    Across 73 trials in 1061 healthy adults, dietary nitrate supplementation improved power output by 4.6 watts, time to exhaustion by 25.3 seconds and distance covered by 163.7 metres versus placebo. It did not improve time-trial performance, perceived exertion, VO2max or blood lactate.

    ⚠What it shows: Strong evidence overall: results pooled from 73 trials covering 1061 healthy adults, graded with a standard confidence framework. The catch is that the gains were modest and did not show up in time-trial performance, the test closest to actual racing.Meta-analysis · J Int Soc Sports Nutr

    Full breakdown →VO₂max explained →VO2max Calculator →The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis. J Int Soc Sports Nutr 2021

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