Supplement Industry Statistics: Use, Efficacy, & Safety

About 58% of US adults aged 20+ use at least one dietary supplement

Multivitamins, vitamin D, and omega-3 are the most commonly used. Use is more prevalent among older adults, women, and those with higher education and income.

Creatine supplementation increases 1RM strength by ~8% above resistance training alone

Meta-analysis of 53 studies. Creatine is one of the very few supplements with consistently positive performance effects in RCTs.

Caffeine improves endurance performance by ~3% and strength performance by ~7% at 3-6 mg/kg doses

Effect is consistent across timing and exercise modalities. Habituation reduces but does not eliminate the effect.

Protein supplementation beyond a total of ~1.6 g/kg/day produces no further benefit on muscle and strength gains

Whole-food protein produces equivalent results to supplemental protein at matched doses. Powders are convenient, not magical.

BCAA (branched-chain amino acid) supplementation does not stimulate muscle protein synthesis when total protein intake is adequate

BCAAs alone are insufficient for MPS. Effects observed in studies typically reflect under-fed comparison groups, not unique BCAA effects.

Vitamin D supplementation reduces falls in older adults at high baseline deficiency risk

Effect is strongest at 700-1,000 IU/day. Routine high-dose supplementation in non-deficient adults shows no clear benefit and may cause harm.

Up to 25% of dietary supplements contain undeclared substances or fail label-claim accuracy in independent testing

Banned stimulants and undeclared steroids are most common in weight-loss and bodybuilding supplements. Third-party certification (NSF, Informed-Sport) reduces but does not eliminate risk.

FDA does not require pre-market approval for supplement safety or efficacy

Manufacturers self-attest to safety. Action is post-market and reactive, typically requiring documented adverse events. Roughly 50,000+ supplement products are on the US market.

Beta-alanine supplementation improves high-intensity exercise of 1-4 minute duration by ~2-3%

Meta-analysis. Effect is largest in repeated-effort protocols. Loading dose is 4-6 g/day for 4+ weeks; tingling (paresthesia) is the main side effect.

Omega-3 supplementation does not measurably reduce major cardiovascular events in low-risk populations

Meta-analysis of 10 trials (n=77,917). Earlier observational signals were not confirmed in pooled RCT data. Some specific high-risk populations may still benefit.

Multivitamins do not measurably reduce all-cause mortality, cancer, or cardiovascular events in well-fed adults

Pooled analysis of 3 large US cohorts (n=390,124). No reduction in mortality after 20+ years of follow-up.

Pre-workout supplements typically derive their performance effect from caffeine alone

Other ingredients (citrulline, beta-alanine) contribute small additional effects but are usually under-dosed in commercial products. Caffeine pills are equivalent.

Iron supplementation improves athletic performance only in iron-deficient or anemic individuals

Routine iron supplementation in iron-replete athletes provides no benefit and risks GI side effects and toxicity over time.

Approximately 23,000 ER visits per year in the US are attributable to dietary supplement adverse events

Most cases involve weight-loss or energy-promoting products. Cardiovascular symptoms are the most common presenting complaint.

Third-party certifications (NSF Certified for Sport, Informed-Sport) reduce contamination risk by detecting >270 banned substances

Mandatory for many professional and Olympic athletes. Reduces but does not eliminate risk; testing is batch-based.