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Sports supplement evidence checker
Check how strong the evidence is for a sports supplement before you buy it.
Short answer: Only a few sports supplements have strong evidence: caffeine, creatine, beta-alanine, sodium bicarbonate, nitrate (beetroot juice) and glycerol, plus sports foods such as drinks, gels and protein powder. Most others have little or emerging evidence, and some are banned or at high risk of contamination.
29 results
Caffeine
Group A: strong evidenceReduces tiredness and effort; improves endurance and many high-intensity efforts.
How it is used in studies: 3–6 mg per kg of bodyweight about 60 minutes before; lower doses around 3 mg/kg also work.
Caution: Jitters, fast heart rate, stomach upset and poor sleep. Healthy adults: about 200 mg in one go and 400 mg a day (EFSA).
Source: Guest et al. (2021), ISSN
Creatine monohydrate
Group A: strong evidenceImproves repeated high-intensity efforts and helps gains in strength and muscle with training.
How it is used in studies: 3–5 g a day; an optional loading phase of about 20 g a day (split into 4) for 5–7 days.
Caution: Expect a small rise in bodyweight from water stored in muscle.
Source: Kreider et al. (2017), ISSN
Beta-alanine
Group A: strong evidenceRaises muscle carnosine, which buffers acid; helps hard efforts lasting about 30 seconds to 10 minutes.
How it is used in studies: 4–6 g a day, split into doses of 2 g or less, for at least 2–4 weeks.
Caution: Harmless tingling (paraesthesia), reduced by smaller split doses or slow-release forms.
Source: Trexler et al. (2015), ISSN; Saunders et al. (2017)
Sodium bicarbonate
Group A: strong evidenceBuffers acid in the blood; helps hard efforts of about 30 seconds to 12 minutes.
How it is used in studies: 0.2–0.5 g per kg of bodyweight (0.3 g/kg is most studied), 60–180 minutes before.
Caution: Stomach upset and diarrhoea are common; try it in training, with a meal, or split the dose.
Source: Grgic et al. (2021), ISSN
Nitrate (beetroot juice)
Group A: strong evidenceLowers the oxygen cost of exercise; may help efforts of about 12–40 minutes, mainly in non-elite athletes.
How it is used in studies: About 5–9 mmol (310–560 mg) nitrate 2–3 hours before; several days of use may help more.
Caution: Red urine is harmless. Antibacterial mouthwash blunts the effect.
Source: Maughan et al. (2018), IOC; Senefeld et al. (2020)
Glycerol
Group A: strong evidenceTaken with fluid to hold extra water before long events in the heat.
Caution: Bloating, headache and short-term weight gain. Use only with expert advice and practise in training.
Source: AIS Sports Supplement Framework
Sports drinks
Group A: strong evidenceCarbohydrate, fluid and sodium in one during and after exercise.
Caution: Count them as part of your carbohydrate for the day.
Source: AIS Sports Supplement Framework
Sports gels and chews
Group A: strong evidenceA compact source of carbohydrate during long events.
Caution: Practise in training to avoid stomach upset.
Source: AIS Sports Supplement Framework
Electrolyte replacement
Group A: strong evidenceReplaces sodium lost in heavy sweating over long events.
Caution: Does not stop overdrinking causing low sodium; drink to thirst or sweat rate.
Source: AIS Sports Supplement Framework
Protein powder
Group A: strong evidenceA convenient way to reach daily protein, after training or before sleep.
Caution: Food works as well; choose batch-tested products if you are drug tested.
Source: AIS Sports Supplement Framework
Sports bars
Group A: strong evidencePortable carbohydrate and protein when meals are hard to fit in.
Caution: Some are high in fibre or sugar alcohols; check before hard sessions.
Source: AIS Sports Supplement Framework
Liquid meal
Group A: strong evidenceEnergy and nutrients when appetite or time is limited.
Caution: Not a substitute for regular meals over long periods.
Source: AIS Sports Supplement Framework
Vitamin D
Group A: strong evidenceMedical supplement for correcting or preventing low vitamin D. The NHS advises 10 micrograms a day in autumn and winter.
Caution: Higher doses only on medical advice.
Source: AIS Sports Supplement Framework; NHS
Iron
Group A: strong evidenceMedical supplement only when a blood test shows low iron.
Caution: Do not take without a diagnosed need: too much iron is harmful. Speak to your GP.
Source: AIS Sports Supplement Framework
Calcium
Group A: strong evidenceMedical supplement when diet cannot meet needs, for example with no dairy.
Caution: Use on the advice of a doctor or dietitian.
Source: AIS Sports Supplement Framework
Multivitamin
Group A: strong evidenceMedical supplement for limited diets, travel or energy restriction.
Caution: Will not improve performance if your diet already covers your needs.
Source: AIS Sports Supplement Framework
Probiotics
Group A: strong evidenceMedical supplement that may help gut and immune health, for example while travelling.
Caution: Effects depend on the strain.
Source: AIS Sports Supplement Framework
Collagen
Group B: emerging evidenceStudied for tendon and ligament health alongside loading exercise.
Caution: Not a substitute for complete protein for building muscle.
Source: AIS Sports Supplement Framework
Fish oil
Group B: emerging evidenceStudied for recovery, muscle soreness and brain health.
Caution: Evidence for performance is limited; check with your GP if you take blood thinners.
Source: AIS Sports Supplement Framework
Curcumin
Group B: emerging evidenceStudied for reducing muscle soreness and inflammation.
Caution: Evidence is mixed; can interact with some medicines.
Source: AIS Sports Supplement Framework
Tart cherry juice
Group B: emerging evidenceStudied for recovery between hard sessions and sleep.
Caution: High-dose antioxidants may blunt training adaptations if used all the time.
Source: AIS Sports Supplement Framework
Vitamin C (high dose)
Group B: emerging evidenceStudied for immune support during heavy training or travel.
Caution: Long-term high doses (around 1 g a day) blunted training adaptations in some trials.
Source: AIS Sports Supplement Framework; Paulsen et al. (2014)
Ketone esters and salts
Group B: emerging evidenceStudied as a fuel or for recovery in endurance sport.
Caution: Expensive, often causes stomach upset, and has not been shown to improve performance reliably.
Source: AIS Sports Supplement Framework
Menthol
Group B: emerging evidenceStudied as a mouth rinse to feel cooler in the heat.
Caution: Feeling cooler does not lower body temperature.
Source: AIS Sports Supplement Framework
BCAAs
Group C: little evidenceNot listed in Groups A, B or D, so treated as Group C. Little benefit if you already eat enough complete protein.
Caution: Spend the money on protein foods instead.
Source: AIS Sports Supplement Framework
CLA
Group C: little evidenceNot listed in Groups A, B or D, so treated as Group C. Sold for fat loss with little meaningful proof.
Caution: Can cause stomach upset.
Source: AIS Sports Supplement Framework
Banned stimulants
Group D: banned or high riskFound in some pre-workouts and fat burners. Banned in sport and linked to serious side effects.
Caution: Do not use. Check ingredient lists of pre-workout products carefully.
Source: AIS Sports Supplement Framework
Prohormones and hormone boosters
Group D: banned or high riskSold to raise testosterone. Banned in sport or at high risk of containing banned substances.
Caution: Do not use.
Source: AIS Sports Supplement Framework
SARMs
Group D: banned or high riskUnlicensed drugs sold as supplements. Banned in sport at all times.
Caution: Do not use. Linked to liver injury and hormone problems.
Source: AIS Sports Supplement Framework
Supplements can be contaminated with banned substances. If you are drug tested, use only batch-tested products (for example Informed Sport). If you are pregnant, take medicines or have a health condition, ask your GP or pharmacist first.
How the evidence groups work
The Australian Institute of Sport sorts supplements into four groups. Group A has strong evidence when used in the right situation. Group B has emerging evidence and is best used in research or with expert supervision. Group C has little meaningful proof. Group D is banned or at high risk of contamination.
Supplements that actually work for performance
The IOC consensus statement names caffeine, creatine, nitrate, beta-alanine and sodium bicarbonate as the performance supplements with good evidence, each for specific kinds of exercise (Maughan et al., 2018; Peeling et al., 2018). For creatine doses from your bodyweight, use the creatine dosage calculator.
The risk of contaminated supplements
In an international study, about 15% of non-hormonal supplements tested contained steroids not listed on the label (Geyer et al., 2004). Athletes who are drug tested are responsible for anything in their body, so use batch-tested products.
Scientific sources
- Australian Institute of Sport. AIS Sports Supplement Framework.
- Maughan R. J. et al. (2018). IOC consensus statement: dietary supplements and the high-performance athlete. British Journal of Sports Medicine, 52(7), 439–455.
- Peeling P. et al. (2018). Evidence-based supplements for the enhancement of athletic performance. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 178–187.
- Guest N. S. et al. (2021). International Society of Sports Nutrition position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition, 18(1), 1.
- Kreider R. B. et al. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14, 18.
- Trexler E. T. et al. (2015). International Society of Sports Nutrition position stand: beta-alanine. Journal of the International Society of Sports Nutrition, 12, 30.
- Grgic J. et al. (2021). International Society of Sports Nutrition position stand: sodium bicarbonate and exercise performance. Journal of the International Society of Sports Nutrition, 18, 61.
- Senefeld J. W. et al. (2020). Ergogenic effect of nitrate supplementation: a systematic review and meta-analysis. Medicine & Science in Sports & Exercise, 52(10), 2250–2261.
- Geyer H. et al. (2004). Analysis of non-hormonal nutritional supplements for anabolic-androgenic steroids: results of an international study. International Journal of Sports Medicine, 25(2), 124–129.
More endurance tools and guides: Sports nutrition, including the race fuelling and hydration calculator.
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Educational information for adults aged 18 and over. It does not diagnose, treat or manage any medical condition. If you have a health condition, or symptoms that worry you, speak to your doctor or a health professional.