Why do athletes and bodybuilders use dietary supplements?

Many athletes and bodybuilders turn to supplements in hopes of enhancing strength, endurance, and muscle size. Despite these goals, several of these products include potentially harmful substances. Additionally, some supplements like glutamine, choline, methoxyisoflavone, quercetin, zinc/magnesium aspartate, nitric oxide, and L-arginine have not been convincingly shown to boost physical performance.

Which supplements are prohibited by the NCAA?

The National Collegiate Athletic Association (NCAA) maintains a list of banned supplements and substances. It's important to note that some supplements might include prohibited elements without disclosing them on the label. Compounds like BMPEA and DMAA are examples of banned substances under NCAA regulations.

Do people need to take dietary supplements?

For most individuals, a balanced diet provides all necessary nutrients. However, a doctor may suggest supplements in specific cases—for example, vitamin D for those with limited sun exposure or B12 for people who are unable to absorb it well due to age, certain health conditions, or dietary choices like veganism.

What exactly is creatine?

Creatine is a substance the body naturally makes, and it's also popular as a supplement. It may assist modestly with enhancing muscle growth, strength, and physical endurance. However, while it might be helpful for some workouts, the long-term impact of creatine use is not fully understood.

Is it safe to take creatine?

Concerns have been raised that creatine might negatively affect liver or kidney function. There’s also a risk it could lead to compartment syndrome, a serious condition involving pressure build-up in muscles. People who have kidney issues should consult with a healthcare provider before starting creatine and should be monitored closely.

Creatine hasn’t been studied enough in children or teens. Medical groups like the American Academy of Pediatrics advise young people to avoid performance-enhancing supplements such as creatine due to potential risks.

Are supplements for athletic performance effective?

A variety of substances marketed for athletic performance—including glutamine, choline, quercetin, and L-arginine—have been researched, but scientific studies have not proven they are beneficial for improving physical ability.

Beta-alanine, another common supplement, has had mixed results in studies, suggesting limited effectiveness in boosting performance.

Are bodybuilding supplements safe to use?

• The FDA has warned about dangerous hidden substances in supplements, especially those sold for building muscle. These may include pharmaceutical drugs or controlled substances not disclosed on the label.

• Some of these products are illegally spiked with anabolic steroids, artificial hormones designed to rapidly boost muscle growth.

• Cases of liver damage linked to bodybuilding supplements have grown in recent years, making it the most frequent cause of liver issues among users of herbal and dietary supplements.

• BMPEA and DMAA are stimulants that have been linked to serious health complications. Despite efforts to ban DMAA-containing products, they still occasionally appear, sometimes listed under misleading names like "geranium oil."

• It’s important to know that BMPEA doesn't naturally occur in the herb Acacia rigidula, despite some product labels suggesting otherwise.

• Always consult a healthcare provider before using any supplement for physical performance, especially because high doses of certain nutrients or interactions with medications can have harmful effects.

Additional Resources

NCCIH Information Hub

The NCCIH provides materials about complementary health practices. Although it offers helpful information, it does not offer medical advice or referrals.

Toll-free: 1-888-644-6226

TRS: 7-1-1

Know the Science Initiative

This NIH program helps consumers better understand scientific research, offering tools like quizzes, videos, and articles to support informed health decisions.

PubMed®

PubMed® is a database that houses a vast range of scientific and medical journal articles. It’s useful for locating studies about health topics.

NIH Office of Dietary Supplements

The Office of Dietary Supplements works to spread reliable information about supplements through scientific research and public education.

U.S. Food and Drug Administration (FDA)

The FDA ensures the safety of foods, medications, and supplements. It monitors violations and enforces laws regarding dietary products.

Toll-free: 1-888-463-6332

Center for Food Safety and Applied Nutrition (CFSAN)

CFSAN, part of the FDA, governs the labeling and safety of food and dietary items. It offers advice and tips for choosing supplements wisely.

Toll-free: 1-888-723-3366

Federal Trade Commission (FTC)

The FTC regulates most advertising in the U.S., including ads for dietary supplements, and guards against misleading health claims.

Toll-free: 1-877-382-4357

MedlinePlus

This health resource gathers reliable content from government agencies and health organizations to assist consumers with medical questions.

Dietary Supplement Label Database

This centralized collection from the NIH contains label data from thousands of supplements sold in the U.S., including nutrient comparisons.

Key Studies and References

• Alvares TS et al. 2014. Study on L-arginine supplementation in trained runners.

• Austin KG et al. 2016. Examination of supplement use by soldiers under different conditions.

• Bellinger PM. 2014. Review of beta-alanine in athletic settings.

• Candow DG et al. 2014. Review on creatine's impact on aging muscles.

• Deminice R et al. 2013. Effects of creatine on stress and inflammation after exercise.

• Herriman M et al. 2017. Issues around teens' access to dietary supplements.

• Knapik JJ et al. 2016. Systematic review of how common supplement use is among athletes.

• Ko R et al. 2014. Beta-alanine supplement evaluation for military personnel.

• Melina V et al. 2016. Discussion of nutrient considerations in vegetarian diets.

• Navarro VJ et al. 2014. Study on liver injuries from supplements in the U.S.

• Ronis MJJ et al. 2018. Analysis of side effects linked to supplements.

Acknowledgments

The NCCIH extends thanks to David Shurtleff, Ph.D., for his role in reviewing this material.

This document is in the public domain and available for free use and reproduction.

The NCCIH provides this information to support awareness. It should not replace advice or treatment from a qualified health provider. Any product references are informational and not endorsements.