Three in four Americans take a dietary supplement, but usage rates and evidence quality are two very different things. Below is a sourced breakdown of who actually takes supplements, what the research does and does not support, and how much independent policing the industry actually gets.
Every figure below links directly to its source. Where market-research firms disagree with each other, both estimates are shown rather than picking one.
Table of Contents
- Adoption & Usage
- Market Size & Growth
- Evidence Tier: What’s Actually Proven
- Label Accuracy & Contamination
- Regulation & Enforcement
- Third-Party Certification
- Consumer Trust & Skepticism
- Demographic Usage Patterns
Adoption & Usage
Industry and government surveys tell slightly different stories, so both are shown here.
- 75% of Americans reported using a dietary supplement in 2024, a rate that has held roughly steady for several years. (CRN, 2024)
- That is down slightly from the industry’s reported all-time high of 77% in 2019. (CRN, 2019)
- Government data is more conservative: 57.6% of US adults aged 20 and over used any dietary supplement in the past 30 days, per NHANES 2017–2018 data. (CDC/NCHS, 2021)
- Usage is higher among women (63.8%) than men (50.8%). (CDC/NCHS, 2021)
Usage climbs sharply with age. Among men it rises from 35.9% (ages 20–39) to 67.3% (60+). Among women it rises from 49.0% (ages 20–39) to 80.2% (60+). (CDC/NCHS, 2021)
- Among all adults, 42.4% used no supplements in the past 30 days, 22.5% used exactly one, 13.8% used two, 7.5% used three, and 13.8% used four or more. (CDC/NCHS, 2021)
- Long-run adoption has grown steadily: age-adjusted use among adults 20–39 rose from 34.7% in 2007–2008 to 42.5% in 2017–2018. (CDC/NCHS, 2021)
- Multivitamin-minerals remain the most common category across every age band: 24.0% of adults 20–39, 29.8% of adults 40–59, and 39.4% of adults 60+ use one. (CDC/NCHS, 2021)
Among supplement users, 91% say supplements are essential to maintaining their health, and 71% report loyalty to a specific brand. (CRN, 2024) Median monthly spend among users was $50 in 2024, up slightly from $48 in 2023. Users who buy through a healthcare professional spend a median of $100 per month. (CRN, 2024)
The top reasons cited for supplement use are overall health and wellness (42%), immune health (30%), and energy (27%). (CRN, 2024)
Market Size & Growth
Market-research firms disagree substantially on the size of the global dietary supplements market, likely due to differing scope definitions.
- Grand View Research puts the global market at $209.5 billion in 2025, growing to $431.7 billion by 2033 at a 9.5% CAGR, with North America holding a 36.1% revenue share. (Grand View Research, 2026)
- Fortune Business Insights sizes the same global market at roughly half that: $100.9 billion in 2025, growing to $219.3 billion by 2034. (Fortune Business Insights, 2026)
- The global protein supplements market is projected to grow from $32.9 billion in 2026 to $66.2 billion by 2034, a 9.1% CAGR. (Fortune Business Insights, 2026)
- The weight-loss supplement category specifically was estimated at $43.9 billion in 2022, projected to reach $135.7 billion by 2030. (JAMA Network Open, 2024)
Evidence Tier: What’s Actually Proven
A small handful of supplement categories have consistent, well-replicated backing in the peer-reviewed literature.
- Creatine monohydrate combined with resistance training reliably augments gains in muscular strength and power output across the published trial base. (Nutrients, 2023)
- Caffeine has similarly strong support for endurance and power output. A meta-analysis of cycling performance found caffeine significantly reduced time-trial completion time (SMD −0.36, p<0.01) and significantly increased mean power output (SMD 0.29, p<0.05), pooled across more than a dozen studies with low heterogeneity. (PMC meta-analysis, 2025)
- Protein supplementation has a similarly deep evidence base: a 2022 meta-analysis confirmed it augments the adaptive response of skeletal muscle to resistance training. (J Cachexia Sarcopenia Muscle, 2022)
- Vitamin D correction is the clearest “deficiency-to-benefit” case in the category, simply because deficiency is so common: 28.9% of US adults are vitamin D deficient (<50 nmol/L) and 41.4% are insufficient (50–<75 nmol/L). (NHANES analysis, 2022)
At the other end of the spectrum, weight-loss and “proprietary blend” categories carry both weaker evidence and dramatically higher adulteration risk, shown directly in the next section. (JAMA Network Open, 2024)
Label Accuracy & Contamination
This is not a one-off finding from a single study. It’s the consistent result of three independent testing efforts published across 2024 and 2025, using different labs, different products, and different sample sources.
- May 2024: 30 weight-loss supplements purchased from online retailers advertising military discounts, tested by liquid chromatography-mass spectrometry. 83% (25 of 30 products) had inaccurate labels. (JAMA Network Open, 2024)
- December 2024: 44 weight-loss supplements purchased physically on or near US military bases. An almost identical 82% (36 of 44 products) had inaccurate labels, and 91% failed the Department of Defense’s OPSS Risk Assessment Scorecard outright. (Nutrients, 2024)
- May 2025: the most recent and broadest look yet, a systematic review and meta-analysis pooling 22 international testing studies, put the median prevalence of pharmaceutical adulteration in weight-loss “natural” products at 37.5% (interquartile range 25.9%–49.6%). The appetite-suppressant drug sibutramine was the single most common adulterant, at a median 21.8% contamination rate. (Frontiers in Pharmacology, 2025)
The gap between the roughly 82–83% figures and the 37.5% pooled median is scope, not disagreement. The two 2024 studies counted any label inaccuracy, including harmless ones, while the 2025 meta-analysis counted only confirmed illegal pharmaceutical adulterants, a stricter bar that still found more than a third of products failing.
Taken together, this is the most current, most rigorously verified picture available as of 2026: the weight-loss supplement category has an adulteration problem that has not improved, and is now more precisely documented than it was two years ago.
The original JAMA study also found detail worth breaking out on its own:
- 80% (24 of 30) were misbranded, meaning a listed ingredient was not actually detected. (JAMA Network Open, 2024)
- 23% (7 of 30) contained hidden ingredients not disclosed anywhere on the label, including 1,4-DMAA, yohimbine, and a cheaper substitute plant sold in place of labeled saffron. (JAMA Network Open, 2024)
- 30% (10 of 30) contained a substance on the Department of Defense’s Prohibited Dietary Supplement Ingredients List, either disclosed or hidden. (JAMA Network Open, 2024)
- Zero of the 30 products carried an independent third-party certification seal (no BSCG, NSF Certified for Sport, Informed Sport, or USP mark). Fourteen carried a generic GMP seal, which the study’s authors note is not equivalent to independent contaminant or potency testing. (JAMA Network Open, 2024)
The safety consequences are measurable at a national level, though the most rigorous estimate available is now over a decade old. A landmark surveillance study estimated roughly 23,000 emergency department visits per year in the US are attributed to adverse events from dietary supplements, resulting in an estimated 2,154 hospitalizations annually.
Weight-loss and energy products caused an estimated 71.8% of supplement-related adverse events involving cardiac symptoms among single-supplement cases. (NEJM, 2015)
No nationally representative study has updated this figure since it was published in 2015, using surveillance data from 2004–2013. We’re not aware of a more recent equivalent, and we’re flagging that gap rather than implying a newer number exists.
Direct-to-consumer online supplement sales have expanded substantially since 2015, and the 2024-2025 label-accuracy studies above show the underlying adulteration problem is undiminished.
There’s no evidence the true current rate is lower than this 2015 estimate, and reasonable grounds to suspect it understates 2026 exposure.
Contamination with banned or undeclared compounds is not limited to weight-loss products. A review of unintentional-doping research cites a German testing study in which 14.8% of 634 tested dietary supplements were found to contain undeclared anabolic steroid compounds. (PMC review, 2022)
Separately, the FDA’s own Weight Loss Tainted Products Database has flagged more than 100 products containing hidden pharmaceutical ingredients such as undisclosed prescription drugs. (FDA)
Regulation & Enforcement
The regulatory gap that underlies most of the findings above traces back to a single piece of legislation. Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), dietary supplements are not required to undergo FDA premarket approval for safety or efficacy before being sold, unlike prescription or over-the-counter drugs. (FDA)
FDA’s role is largely reactive: it maintains a running Health Fraud Product Database of products already cited in warning letters, recalls, and public safety notifications, rather than screening products before they reach shelves. (FDA)
A 2009 Government Accountability Office report found FDA had gaps in its ability to identify and act on dietary supplement safety concerns, a finding that, while dated, describes a structural issue that has not fundamentally changed under DSHEA since. (GAO, 2009)
Enforcement does happen at the marketing-claims level. In December 2024, the FTC and the New York Attorney General won summary judgment against Quincy Bioscience over deceptive marketing claims for the memory supplement Prevagen, closing out a case first filed in 2017. (FTC, 2024)
Third-Party Certification
Because DSHEA does not require premarket testing, independent certification programs have become the main way consumers can verify what is actually in a product.
- NSF’s Certified for Sport program tests products for 290 banned substances along with label-content confirmation, and is the only third-party certification recognized by USADA, Major League Baseball, the NHL, and the Canadian Football League (recommended, though not required, by the NFL, NBA, PGA, and LPGA). (NSF International)
- The USP Verified Mark has appeared on more than 700 million supplement labels and packages since the program’s inception, confirming ingredient identity, declared potency, and screening for specified contaminants. (USP)
- Informed Sport, LGC’s batch-testing certification program, currently lists more than 2,000 banned-substance-tested products in its searchable database. (Informed Sport / LGC)
Informed Sport’s own materials put the scale of the underlying problem in context: as many as 1 in 10 sports supplements may be contaminated with substances prohibited in sport, and product contamination was responsible for an estimated 8% of all anti-doping rule violations between 2005 and 2022, per analysis by the Anti-Doping Knowledge Centre. (Informed Sport / LGC)
Consumer Trust & Skepticism
Independent academic research on consumer trust in supplement advertising is thinner than industry-reported figures.
- One analysis of dietary supplement advertisements found that nearly 30% still contained unauthorized health claims even after a prior regulatory agreement aimed at curbing them, based on a review of 46 ads. (Nutrients (MDPI), 2026)
- Skepticism toward that advertising did not vary much by how much a consumer actually knew about nutrition. The gap in trust between high-knowledge and low-knowledge respondents was no more than 2.2 percentage points, suggesting general wariness of supplement marketing claims is widespread, not concentrated among more informed consumers. (Nutrients (MDPI), 2026)
Demographic Usage Patterns
The clearest verified demographic pattern in the data is age, not generation-branding. The number of different supplements a person takes climbs steadily with age: use of exactly two supplements rises from 10.2% of adults 20–39 to 17.3% of adults 60+, and use of four or more rises from 6.8% to 24.9% across the same age range. (CDC/NCHS, 2021)
Combined with the age-based usage-prevalence gap noted earlier, supplement use roughly doubling from the 20–39 bracket to the 60+ bracket in both sexes, the data supports a simple pattern: supplement use is not just more common with age, it also compounds, with older adults taking more products simultaneously than younger adults. (CDC/NCHS, 2021)
Athletic Insight covers supplement reviews and research. The full sourced stats ledger behind this page, including rejected and unverifiable figures, is available on request.
