Are supplements the “magic pill”?
Nutrition Foundation Pillar
Over the past four decades, the use of supplements has risen from about 25% to 70% of the population. The appeal is understandable: changing your diet or exercising takes effort, whereas a capsule promises a shortcut. But what does the science say, without sugarcoating it?
Neither medicine nor magic
A dietary supplement is not a drug: it is not intended to treat or cure a disease. Importantly, in several countries, including the United States, supplements can be marketed without prior approval regarding their safety or effectiveness. There are also risks of contamination—a serious concern for athletes, as some products contain banned substances. Look for the cGMP and NSF (or Informed Sport) labels
When They're Useful
When used properly, supplements offer real value: they have helped eliminate deficiency diseases (goiter, scurvy) and assist populations that struggle to meet their nutritional needs, such as the elderly or people with a confirmed deficiency. The key is targeting: addressing an actual deficiency, not blindly “playing it safe.”
When they cause harm
Because more isn't always better. Beyond the recommended levels, certain supplements increase risks: excessive calcium intake has been linked to more hip fractures and heart attacks; high doses of vitamins A and E have been linked to an increased risk of lung cancer and mortality. Replacing a varied diet with supplements is a bad idea.
It's the same message as for micronutrients: focus on what's on your plate first.
Weight Loss: There Are No Shortcuts
Weight-loss supplements promise quick and easy results, but most have not been rigorously tested or are potentially contaminated. The proven effects are modest at best (for example, carnitine or CLA, which result in small amounts of weight loss that fade over time). A healthy diet and physical activity remain the primary approach; supplements, at best, are a supplementary measure.
As the name suggests, it's a supplement… there's generally no point in taking it if your diet isn't already optimal.
Performance: What Has Actually Been Proven
When it comes to effectiveness, only a few supplements are backed by solid evidence—and two stand out from the rest:
Caffeine: effective for both endurance and short, repeated efforts when taken in moderate doses (3 to 6 mg/kg, 30 to 90 minutes before exercise). At doses above 9 mg/kg, there is no additional benefit, but side effects may occur.
Creatine monohydrate: the most extensively studied supplement . It enhances short-duration, high-intensity exercise performance, promotes gains in strength and muscle mass, and supports recovery. Typical regimen: a loading phase (~20 g/day spread over 5 to 7 days), followed by 3 to 5 g/day for maintenance. No adverse long-term effects have been reported with proper use.
Others (beet nitrates, beta-alanine) offer more limited and specific benefits; HMB, on the other hand, offers no additional benefits to those who already consume enough protein.
Recovery: A Matter of Nuance
Be cautious with high doses of antioxidants: they can hinder adaptations to endurance training. When it comes to omega-3s, fish is better than capsules. For vitamin D, get a blood test first before taking supplements. And there’s no point in taking them if you don’t spend time outdoors to metabolize them. In short, focus on what you need rather than just taking more.
The conclusion is always the same: diet and training come first; supplements should be used only as a complement, chosen in consultation with a healthcare professional—especially for athletes, given the risks of contamination.
References
Maughan RJ et al. “IOC Consensus Statement: Dietary Supplements and the High-Performance Athlete.” Int J Sport Nutr Exerc Metab. 2018;28(2):104-125.
Rawson ES, Miles MP, Larson-Meyer DE. “Dietary Supplements for Health, Adaptation, and Recovery in Athletes.” Int J Sport Nutr Exerc Metab. 2018;28(2):188-199.
Barrea L et al. “Nutrition and Obesity: A Brief Overview of the Efficacy, Safety, and Drug Interactions of the Main Weight-Loss Dietary Supplements.” Int J Obes Suppl. 2019;9(1):32-49.
Onakpoya IJ, Wider B, Pittler MH, Ernst E. “Food supplements for body weight reduction: a systematic review of systematic reviews.” Obesity (Silver Spring). 2011;19(2):239-244.
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This article is provided for educational purposes only and does not constitute medical advice. If you have any health conditions, consult a doctor before starting to exercise.
