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Which supplements actually work
The short answer. Of the 50 supplements this site compares, 11 have strong evidence, 21 moderate evidence and 18 weak evidence. The ones with the most evidence are also the cheapest: melatonin comes to €0.72 a month at the dose used in the studies. The expensive stuff is almost always in the bottom half of this page.
There is no numbered top 10, on purpose: creatine and caffeine do different things and there is no scale that ranks them against each other. What can be ranked is how much evidence each has and what the dose used in the studies costs. The effect always belongs to the ingredient, never to a brand.
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01 Strong evidence: 11 supplements
From cheapest to dearest per month
Several meta-analyses or position stands from scientific societies agree that there is an effect.
| Supplement | What has been measured | Per month | Products |
|---|---|---|---|
| Melatonin1 mg. Going up to 3, 5 or 10 mg does not improve the effect and increases grogginess the next day. | Time to fall asleep: a few minutes lessReglamento (UE) 432/2012 de la Comision: lista de declaraciones autorizadas. La melatonina contribuye a disminuir el tiempo necesario para conciliar el sueno; condicion de uso: 1 mg por porcion, poco antes de acostarse. | €0.72with Melatonina 1,95 mg PURA - 500 Comprimidos from Amazon | 116 |
| Caffeine3 to 6 mg per kilo of body weight, 30 to 60 minutes before. | Endurance: where it works bestGuest NS et al. ISSN position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18:1. Dosis ergogenica de 3-6 mg/kg, 30-60 minutos antes; sin beneficio adicional por encima de 9 mg/kg. | €0.76with Cafeína - 500 Comprimidos - 200 mg por Comprimido from Amazon | 86 |
| Creatine3 to 5 g a day, every day, whether you train or not. | Maximal strength and power: +5 to 15 %Kreider RB et al. ISSN position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. | €0.80with Firm Foods Creatina 2 kg (2x 1 kg) from Zumub | 223 |
| Omega 3250 mg a day of EPA+DHA combined as a general reference. Uses at 2-3 g are something else and have a doctor behind them. | Blood triglycerides: -20 to -30 %EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on Dietary Reference Values for fats. EFSA Journal. 2010;8(3):1461. Ingesta adecuada de 250 mg diarios de EPA+DHA. | €1.22with Mensan Omega 3 660 Mg 220 Perlas from Bulevip | 152 |
| Vitamin C80 mg covers the reference value; common presentations range from 500 to 1000 mg. | Functions authorised in the EU: collagen, immunity, iron and tirednessReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Vitamina C, 80 mg. | €1.65with Zumub Vitamina C 1000mg 200 comprimidos (4x 50) from Zumub | 127 |
| Beta-alanine4 to 6 g a day, split into 2 to 4 servings of 1 to 2 g. | Time to effect: 2 to 4 weeksTrexler ET et al. ISSN position stand: Beta-Alanine. J Int Soc Sports Nutr. 2015;12:30. 4-6 g diarios durante 2-4 semanas; efecto en esfuerzos de 1 a 4 minutos; parestesia como efecto adverso habitual. | €2.68with Zumub Beta-Alanina 250g (2x 125g) from Zumub | 36 |
| Vegan protein25 to 40 g per serving. The daily target is still 1.4 to 2.0 g per kilo of body weight. | Leucine needed per serving: 700 to 3000 mgJager R et al. ISSN position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. Dosis de 20-40 g por toma y 700-3000 mg de leucina para maximizar la sintesis proteica. | €5.54with Zumub Proteína vegana (proteína de guisante) 4 Kg (2x 2 Kg) from Zumub | 141 |
| Whey protein (concentrate)20 to 40 g per serving. What counts is the daily total: 1.4 to 2.0 g per kilo of body weight. | Strength (1RM): +2.49 kgMorton RW et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384. 49 estudios, 1863 participantes. | €16.90with HSN Sport Series Evobasic whey 2Kg from HSN | 251 |
| Whey protein isolate20 to 40 g per serving; the daily total is still 1.4 to 2.0 g per kilo. | Lactose: almost nonede Wit JN. Nutritional and functional characteristics of whey proteins in food products. J Dairy Sci. 1998;81(3):597-608. Los aislados parten del 90 % de proteina y los concentrados comerciales van del 35 % al 80 %. | €18.40with Bulk Whey Protein Isolate, Sin sabores añadidos, 1 kg from Amazon | 182 |
| Carbohydrates30 to 60 g per hour of long continuous effort. Outside that, the day’s food. | Efforts of 1 to 2.5 hours: 30 to 60 g per hourThomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Med Sci Sports Exerc. 2016;48(3):543-568. 30-60 g/h en esfuerzos de 1-2,5 h y hasta 90 g/h con fuentes multiples por encima de 2,5 h. | no published dose | 113 |
| Vitamin B12On a vegan diet, the usual approach is a high weekly dose or a smaller daily one. Adjust it with whoever manages your case. | Functions authorised in the EU: red blood cells, energy and tirednessReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Vitamina B12, 2,5 microgramos. | no published dose | 106 |
02 Moderate evidence: 21 supplements
From cheapest to dearest per month
There are studies in favour, but few, with small samples or measuring markers instead of outcomes.
| Supplement | What has been measured | Per month | Products |
|---|---|---|---|
| CalciumThe labelling reference is 800 mg a day counting all food, not just the supplement. | Bone density with supplements: +0.7 to 1.8%Tai V, Leung W, Grey A, Reid IR, Bolland MJ. Calcium intake and bone mineral density: systematic review and meta-analysis. BMJ. 2015;351:h4183. Cincuenta y nueve ensayos: el calcio de la dieta aumento la densidad mineral osea un 0,6-1,0 % al ano y un 0,7-1,8 % a dos anos, y los suplementos un 0,7-1,8 % en los cinco puntos medidos, con incrementos pequenos y no progresivos que es poco probable que reduzcan de forma clinicamente significativa el riesgo de fractura. | €1.50with Sotya Calcio + Vitamina D Masticable 1g 100 comprimidos from DosFarma | 43 |
| MagnesiumWhatever is missing to get close to the day’s 375 mg counting food, not the whole tub by default. | Functions authorised in the EU: muscle, nervous system and tirednessReglamento (UE) 1169/2011 sobre la informacion alimentaria facilitada al consumidor, Anexo XIII: valores de referencia de nutrientes. Magnesio, 375 mg. | €1.61with Sotya Quelato de magnesio 100 comprimidos de 900mg from Sotya | 154 |
| Vitamin EThe European labelling reference is 12 mg. There is no reason to look for high-dose products. | Mortality with high doses: +39 per 10,000Reglamento (UE) 1169/2011 sobre la informacion alimentaria facilitada al consumidor, Anexo XIII: valores de referencia de nutrientes. Vitamina E, 12 mg. Es un valor de ETIQUETADO, no una dosis con efecto demostrado. | €2.69with HSN Essential Series Vitamina E 400UI 120 perlas from HSN | 41 |
| ZincAround the 10 mg reference value, counting what the diet already provides. | Functions authorised in the EU: immunity, cells and normal testosteroneReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Zinc, 10 mg. | €2.87with Holland & Barrett Zinc 15mg - 240 Comprimidos from Holland & Barrett | 81 |
| Turmeric500 to 1000 mg of curcuminoids a day, in two servings. | Joint pain (knee osteoarthritis): improves versus placeboDaily JW, Yang M, Park S. Efficacy of turmeric extracts and curcumin for alleviating the symptoms of joint arthritis: a systematic review and meta-analysis of randomized clinical trials. J Med Food. 2016;19(8):717-729. Alrededor de 1000 mg/dia de curcuminoides en los ensayos incluidos. | €5.00with Swanson Full Spectrum® Boswellia & cúrcuma 300mg/300mg 60 cápsulas from HSN | 114 |
| Potassium and electrolytesThe labelling reference is 2000 mg a day, counting all food. | Systolic blood pressure in hypertensive people: -3.49 mmHgAburto NJ et al. Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses. BMJ. 2013;346:f1378. Veintidos ensayos con 1606 participantes: descenso de 3,49 mmHg de tension sistolica (IC 95 % 1,82-5,15) y 1,96 mmHg de diastolica, solo en personas con hipertension; once cohortes con 127.038 participantes: riesgo de ictus 0,76 (IC 95 % 0,66-0,89). | €5.00with Hivital Potasio 1000mg 240 Cápsulas from DosFarma | 34 |
| Citrulline6 to 8 g of citrulline malate, or 3 to 5 g if the product is pure citrulline. | Reps in sets to failure: a few moreKerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. Citrulina malato en el rango de 6-8 g por toma en los estudios de rendimiento. | €5.25with Ecolac L-Citrulina Dl-Malato 2:1 Bote 500 gr from Bulevip | 42 |
| IronWhatever the person who has seen your blood test says. The labelling reference value is 14 mg. | Functions authorised in the EU: red blood cells, oxygen and tirednessReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Hierro, 14 mg. | €5.99with Solaray Hierro 25mg 60 Cápsulas Vegetales from DosFarma | 101 |
| Collagen10 to 15 g of hydrolysed collagen or gelatin, with about 50 mg of vitamin C. | Collagen synthesis (PINP marker in blood): x2Shaw G et al. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. Am J Clin Nutr. 2017;105(1):136-143. 15 g de gelatina con vitamina C una hora antes del ejercicio. | €6.25with Zumub Hydrolysed Collagen Powder 600 gramos (2x 300g) from Zumub | 168 |
| Ashwagandha300 to 600 mg a day of standardised extract, split or in one serving. | Perceived stress: improves versus placeboPratte MA et al. An alternative treatment for anxiety: a systematic review of human trial results reported for the Ayurvedic herb ashwagandha (Withania somnifera). J Altern Complement Med. 2014;20(12):901-908. | €7.24with Life Pro ASHWAGANDHA 500MG KSM66 90 VEGANCAPS from Life Pro | 119 |
| Essential amino acids (EAA)10 to 15 g per serving, and only if that serving will not include complete protein. | Leucine the serving needs: 700 to 3000 mgJager R et al. ISSN position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. La toma debe aportar 700-3000 mg de leucina dentro de un aporte suficiente de aminoacidos esenciales; los BCAA aislados no superan a una proteina completa. | €9.29with Zumub EAA en Polvo 500g from Zumub | 61 |
| Casein30 to 40 g in the evening serving. The daily total is still 1.4 to 2.0 g per kilo. | Serving before bed: 30 to 40 gJager R et al. ISSN position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. Dosis de 20-40 g de proteina por toma. | €11.03with HSN Sport Series Evocasein 2.0 (caseína micelar + DigeZyme®) 2Kg from HSN | 84 |
| Pre-workoutsCaffeine: 3 to 6 mg per kilo of body weight. For 70 kg, between 210 and 420 mg. Beta-alanine: 4 to 6 g a day. | Caffeine: muscular strength and endurance: consistent effectGuest NS et al. ISSN position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18:1. 3-6 mg/kg de peso corporal. | €26.94with HSN Sport Series Evobomb 500g from HSN | 124 |
| Vitamin B complexThe European labelling references, unless medically advised. They are small amounts. | Performance with poor nutritional status: lower capacity at high intensityWoolf K, Manore MM. B-vitamins and exercise: does exercise alter requirements? Int J Sport Nutr Exerc Metab. 2006;16(5):453-484. Las personas activas con estado nutricional pobre o marginal para una vitamina B pueden tener menor capacidad de rendir a intensidades altas; el ejercicio puede aumentar los requerimientos de riboflavina y vitamina B6, con datos limitados para folato y B12. | no published dose | 38 |
| Weight gainersWhatever is missing to close your daily surplus. There is no reference dose. | Gaining weight: requires a surplusKerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. El balance energetico es lo que determina el cambio de peso; los suplementos calorico-proteicos son una via comoda de alcanzarlo. | no published dose | 96 |
| ProbioticsThe one from that strain’s trial. In general, between one billion and one hundred billion CFU a day. | What matters: the strain, not the genusJager R et al. ISSN position stand: Probiotics. J Int Soc Sports Nutr. 2019;16:62. Los efectos son especificos de cepa; dosis habituales de 10^9 a 10^11 UFC al dia. | no published dose | 107 |
| SeleniumThe labelling reference is 55 micrograms. The tolerable upper limit is 255 micrograms a day. | Tolerable upper limit: 255 µg/dayReglamento (UE) 1169/2011 sobre la informacion alimentaria facilitada al consumidor, Anexo XIII: valores de referencia de nutrientes. Selenio, 55 ug. Es un valor de ETIQUETADO, no una dosis con efecto demostrado. | no published dose | 33 |
| Taurine1 to 6 g, the range of the studies. Within that range the amount did not change the result. | Endurance performance: Hedges’ g 0.40Waldron M, Patterson SD, Tallent J, Jeffries O. The Effects of an Oral Taurine Dose and Supplementation Period on Endurance Exercise Performance in Humans: A Meta-Analysis. Sports Med. 2018;48(5):1247-1253. Diez estudios; mejora global del rendimiento de resistencia con g de Hedges 0,40 (IC 95 % 0,12-0,67); dosis de 1 a 6 g sin efecto de la dosis ni del periodo de suplementacion. | no published dose | 6 |
| L-theanine100 mg with caffeine for the cognitive side, or 200 mg a day for stress and sleep. | Attention combined with caffeine: faster and more accurateOwen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008;11(4):193-198. Veintisiete participantes: 50 mg de cafeina con 100 mg de L-teanina mejoro velocidad y precision en la tarea de cambio de atencion a los 60 minutos y redujo la susceptibilidad a la distraccion a los 60 y 90 minutos. | no published dose | 18 |
| Vitamin DWhatever your blood test calls for. Common presentations range from 1000 to 4000 IU. | Functions authorised in the EU: bones, muscle and immunityReglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Vitamina D, 5 microgramos. | no published dose | 137 |
| Vitamin K2180 micrograms of MK-7 a day, the dose from the three-year trial. | Bone density in spine and femoral neck: less loss at 3 yearsKnapen MHJ, Drummen NE, Smit E, Vermeer C, Theuwissen E. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int. 2013;24(9):2499-2507. 244 mujeres posmenopausicas sanas, 180 ug/dia de MK-7 durante 3 anos: menor descenso asociado a la edad del contenido y la densidad mineral osea en columna lumbar y cuello femoral, sin efecto en cadera total, y mejora del estado de vitamina K medido por el cociente de osteocalcina sin carboxilar. | no published dose | 21 |
03 Weak evidence: 18 supplements
From cheapest to dearest per month
Reviews find no consistent effect. It is listed because it sells, not because it works.
| Supplement | What has been measured | Per month | Products |
|---|---|---|---|
| Glucosamine and chondroitin1500 mg of glucosamine and 1200 mg of chondroitin a day if you decide to try it. | Knee pain across the whole trial: no differenceClegg DO et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med. 2006;354(8):795-808. 1500 mg de glucosamina y 1200 mg de condroitina; sin diferencia frente a placebo en el analisis principal. | €2.11with HSN Essential Series Sulfato de glucosamina 1000mg 120 tabletas from HSN | 101 |
| Glutamine5 to 10 g a day is what the studies use, without that meaning it works. | Sports performance: no demonstrated effectKerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. La glutamina aparece entre los suplementos con evidencia limitada o nula. | €2.47with Zumub Glutamina 1kg from Zumub | 116 |
| BCAA5 to 10 g per serving in the studies, although the dose does not fix the underlying problem. | Muscle protein synthesis: not sustained aloneWolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017;14:30. | €2.62with Zumub BCAA en polvo 1kg Sin Sabor from Zumub | 126 |
| L-carnitine2 to 4 g a day is what the studies use, without that meaning it works. | Fat loss: no consistent effectKerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. La L-carnitina figura entre los suplementos con evidencia limitada o mixta; 2-4 g diarios son la dosis habitual de los estudios. | €3.08with Carnitina 2000mg -200 Comprimidos- Pre Entreno -2932mg L-Carnitina from Amazon | 93 |
| Hyaluronic acid120 mg a day, the dose from the skin trial. | Crow’s feet wrinkles: improvement at 8 weeksOe M et al. Oral hyaluronan relieves wrinkles: a double-blinded, placebo-controlled study over a 12-week period. Clin Cosmet Investig Dermatol. 2017;10:267-273. Sesenta sujetos japoneses de 22 a 59 anos con patas de gallo, 120 mg/dia de hialuronico de 2 kDa o 300 kDa frente a placebo durante 12 semanas: el grupo de 300 kDa mostro arrugas significativamente menores que placebo a partir de las 8 semanas. | no published dose | 24 |
| Arginine0.15 g per kilo in a single serving, or 1.5-2 g a day for several weeks, which is what the studies use. | Aerobic performance: SMD 0.84Viribay A, Burgos J, Fernandez-Landa J, Seco-Calvo J, Mielgo-Ayuso J. Effects of Arginine Supplementation on Athletic Performance Based on Energy Metabolism: A Systematic Review and Meta-Analysis. Nutrients. 2020;12(5):1300. Quince estudios en el metaanalisis: DME 0,84 (IC 95 % 0,12-1,56; I2 89 %) en pruebas aerobicas y DME 0,24 (IC 95 % 0,05-0,43; I2 0 %) en anaerobicas; protocolos de 0,15 g/kg entre 60 y 90 minutos antes. | no published dose | 10 |
| CLA3.2 g a day is the median dose from the meta-analysis. | Fat loss versus placebo: 0.09 kg per weekWhigham LD, Watras AC, Schoeller DA. Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans. Am J Clin Nutr. 2007;85(5):1203-1211. Dieciocho estudios: perdida de grasa frente a placebo de -0,024 kg por gramo de CLA y semana; ajustado a la dosis mediana de 3,2 g/dia, 0,09 kg por semana frente a placebo; efecto lineal hasta 6 meses. | no published dose | 29 |
| Coenzyme Q10100 mg three times a day is the heart failure trial regimen. Products on the market usually provide 30 to 200 mg a day. | Major cardiovascular events in heart failure: 15% vs 26%Mortensen SA et al. The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO. JACC Heart Fail. 2014;2(6):641-649. 420 pacientes, 100 mg tres veces al dia sobre tratamiento estandar: el objetivo compuesto a 2 anos se alcanzo en el 15 % del grupo Q10 frente al 26 % del placebo (HR 0,50; IC 95 % 0,32-0,80), con mortalidad total del 10 % frente al 18 %. | no published dose | 44 |
| Choline and alpha-GPC400 mg of choline a day as the intake reference. Alpha-GPC was tested at 250 and 500 mg a day. | Isometric strength with alpha-GPC: no differencesEFSA NDA Panel. Dietary Reference Values for choline. EFSA Journal. 2016;14(8):4484. Ingesta adecuada de 400 mg/dia para todos los adultos, 480 mg/dia en el embarazo y 520 mg/dia en la lactancia. | no published dose | 24 |
| Spirulina6 g a day is the dose from the performance trial. On the market it is usually sold at 3 to 5 g. | Time to exhaustion: from 2.05 to 2.70 minKalafati M et al. Ergogenic and antioxidant effects of spirulina supplementation in humans. Med Sci Sports Exerc. 2010;42(1):142-151. Nueve varones moderadamente entrenados, diseno cruzado doble ciego, 6 g/dia durante 4 semanas: tiempo hasta el agotamiento de 2,05 a 2,70 minutos, oxidacion de hidratos -10,3 % y de grasa +10,9 %. | no published dose | 30 |
| HMB38 mg per kilo a day, about 3 g for a 70 kg person, split into several servings. | Bench press strength (trained): ES 0.00Sanchez-Martinez J, Santos-Lozano A, Garcia-Hermoso A, Sadarangani KP, Cristi-Montero C. Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trials. J Sci Med Sport. 2018;21(7):727-735. Seis estudios, 193 participantes: efectos triviales y no significativos en press de banca (0,00), prensa de piernas (0,09), peso (-0,01), masa libre de grasa (0,16) y masa grasa (-0,20). | no published dose | 13 |
| Maca1.5 to 3 g a day of powdered root is typical on the market; trials use different preparations and doses, which makes them hard to compare. | Sexual function: limited evidenceShin BC, Lee MS, Yang EJ, Lim HS, Ernst E. Maca (L. meyenii) for improving sexual function: a systematic review. BMC Complement Altern Med. 2010;10:44. Cuatro ensayos aleatorizados: dos favorables en disfuncion o deseo sexual, uno favorable en disfuncion erectil y uno sin efecto en ciclistas sanos; el numero de ensayos, el tamano muestral y la calidad metodologica son demasiado limitados para conclusiones firmes. | no published dose | 33 |
| MultivitaminsThe one on the pack, checking that no micronutrient shoots far above its reference value. | Performance in people without deficiencies: no effectKerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. Los micronutrientes solo mejoran el rendimiento cuando corrigen un deficit previo. | no published dose | 114 |
| Fat burnersThere is no fat burner dose: there are doses of each ingredient. The only way to assess one is to add up caffeine and EGCG and compare them with their own pages. | Ingredients with supporting data: caffeine and green teaJeukendrup AE, Randell R. Fat burners: nutrition supplements that increase fat metabolism. Obes Rev. 2011;12(10):841-851. De los suplementos mas populares (cafeina, carnitina, te verde, CLA, forskolina, cromo, algas y fucoxantina), la cafeina y el te verde son los que cuentan con datos que respaldan sus propiedades sobre el metabolismo de las grasas; para muchos otros falta evidencia. | no published dose | 34 |
| Green teaSupplements on the market provide between 5 and 1000 mg of EGCG a day. The relevant safety limit is staying below 800 mg. | Body weight (meta-analysis): -1.31 kgHursel R, Viechtbauer W, Westerterp-Plantenga MS. The effects of green tea on weight loss and weight maintenance: a meta-analysis. Int J Obes. 2009;33(9):956-961. Once estudios: las catequinas redujeron el peso en 1,31 kg frente a control; el efecto fue de -0,27 kg con consumo habitual alto de cafeina y de -1,60 kg con consumo bajo. | no published dose | 19 |
| Tribulus10 to 20 mg per kilo a day split into three servings, or 450 mg of extract a day, the regimes used in the trials. | Blood testosterone: no changeNeychev VK, Mitev VI. The aphrodisiac herb Tribulus terrestris does not influence the androgen production in young men. J Ethnopharmacol. 2005;101(1-3):319-323. 21 hombres de 20 a 36 anos, 10 y 20 mg/kg/dia durante 4 semanas: sin diferencias significativas frente a control en testosterona, androstenediona ni hormona luteinizante. | no published dose | 24 |
| Tryptophan and 5-HTP1 g or more of tryptophan is what separates the sleep effect in the meta-analysis. 5-HTP is sold at much lower doses because it is one step further along the pathway. | Time awake after falling asleep: -81 min per gramSutanto CN, Loh WW, Kim JE. The impact of tryptophan supplementation on sleep quality: a systematic review, meta-analysis, and meta-regression. Nutr Rev. 2022;80(2):306-316. La suplementacion acorta el tiempo despierto tras el inicio del sueno (-81,03 min/g; DME -1,08); con 1 g o mas, 28,91 minutos frente a 56,55 con menos de 1 g; no afecta a los demas componentes del sueno. | no published dose | 30 |
| ZMAThe one on the pack. Count the zinc and magnesium you already take from other tubs. | Testosterone in trained athletes: no changeWilborn CD et al. Effects of Zinc Magnesium Aspartate (ZMA) supplementation on training adaptations and markers of anabolism and catabolism. J Int Soc Sports Nutr. 2004;1(2):12-20. Sin cambios en testosterona ni en las adaptaciones al entrenamiento frente a placebo. | no published dose | 46 |
The monthly cost assumes one effective dose a day. It comes from multiplying by 30 the price of one dose of the cheapest product that reaches the evidence-backed dose, not from a supplementation plan: someone taking it twice a day pays double, and some categories (carbohydrates, caffeine) are not taken daily. Where it says "no published dose", no product page in that category declares how much active ingredient a serving carries, so the sum cannot be done without making it up.
And for your goal, which one?
The same list, sorted by goal
Questions about which supplements work
Answered with the data on this page
- Which supplements actually work?
- The 11 that appear in this list with strong evidence: melatonin, caffeine, creatine, omega 3, vitamin c, beta-alanine, vegan protein, whey protein (concentrate), whey protein isolate, carbohydrates, vitamin b12. "Works" does not mean they do a lot: it means the effect has been measured several times and holds up. Another 21 have moderate evidence and 18 have weak evidence, which is the polite way of saying they sell better than they perform.
- How much does it cost per month to take the ones that work?
- Less than it seems, because the ones with the most evidence are the cheapest. Melatonin comes to €0.72 a month at the dose used in the studies, with the cheapest product that reaches that dose. The sum is always the same: price of one effective dose times 30 days, at one serving a day.
- Where does the evidence level come from?
- From the sources cited in each guide: ISSN position stands, reviews and meta-analyses, with their DOI. This site does not decide it product by product, because the effect belongs to the ingredient and not to the brand. The evidence text was last reviewed on September 4, 2026; prices are from October 15, 2026.
- And are the ones with weak evidence useless?
- They do less than their label says, which is not the same thing. The 18 in the last section have no effect that holds up in people who already eat enough: glucosamine and chondroitin, glutamine, bcaa, l-carnitine, hyaluronic acid, arginine, cla, coenzyme q10, choline and alpha-gpc, spirulina, hmb, maca, multivitamins, fat burners, green tea, tribulus, tryptophan and 5-htp, zma. Each has its own guide with the sources and the specific case in which they do make sense.