Performance enhancement drugs — evidence‑based overview (for educational purposes only)

Disclaimer: This article is for general educational purposes and does not replace medical advice. Performance‑enhancing drugs (PEDs) can carry serious health and legal risks. Always consult a qualified healthcare professional before making decisions about your health.

Quick summary

• “Performance enhancement drugs” is a broad term covering substances used to improve athletic ability, muscle growth, endurance, focus, or appearance.
• Some PEDs (e.g., anabolic steroids, growth hormone, stimulants) can increase certain aspects of performance—but often at significant health risk.
• Short‑term gains may come with long‑term consequences, including heart disease, hormonal disorders, mental health effects, and fertility problems.
• Evidence quality varies: some effects are well studied (e.g., anabolic steroids and muscle mass), while others rely on small or biased studies.
• Many substances sold online or as “supplements” may be contaminated or mislabeled.

What is known

1. Anabolic‑androgenic steroids (AAS) increase muscle mass and strength

Anabolic steroids are synthetic versions of testosterone. Clinical and observational studies show they can increase muscle size, strength, and recovery speed when combined with resistance training.

However, medical organizations such as the World Anti‑Doping Agency (WADA), the U.S. National Institute on Drug Abuse (NIDA), and the Endocrine Society warn that non‑medical steroid use is associated with:

• Elevated blood pressure and cholesterol changes
• Increased risk of heart attack and stroke
• Liver injury (especially oral steroids)
• Hormonal suppression (testicular shrinkage, infertility)
• Mood changes, aggression, depression

2. Stimulants may improve alertness and short‑term performance

Drugs such as amphetamines, methylphenidate, and high‑dose caffeine can increase focus, reaction time, and reduce perceived fatigue. Some are prescribed for conditions like ADHD.

In healthy individuals, benefits for sports performance are inconsistent and often modest. Risks include:

• Heart rhythm disturbances
• Elevated blood pressure
• Anxiety and insomnia
• Dependence or misuse

3. Human growth hormone (HGH) has limited proven performance benefit

HGH is approved for specific medical conditions (e.g., growth hormone deficiency). In healthy adults, evidence suggests it may increase lean body mass slightly, but this does not reliably translate into improved strength or athletic performance.

Adverse effects may include joint pain, swelling, insulin resistance, and possible increased cardiovascular risk.

4. Erythropoietin (EPO) increases red blood cell count

EPO stimulates red blood cell production and can improve oxygen delivery to muscles. It is medically used for certain types of anemia.

In endurance sports, it can improve performance. However, it thickens the blood, increasing the risk of clots, stroke, and heart attack—especially when used without medical supervision.

5. Testosterone therapy differs from steroid abuse

Testosterone replacement therapy (TRT) is prescribed for men with confirmed hypogonadism (low testosterone with symptoms). When used appropriately under medical supervision, risks are monitored.

Non‑medical use at supraphysiologic doses (higher than normal body levels) carries substantially higher risks. For more on hormonal health, see our guide to testosterone therapy basics.

6. Many “supplements” may contain hidden PEDs

Regulatory agencies such as the U.S. FDA and the European Food Safety Authority report that some dietary supplements marketed for muscle gain or fat loss are adulterated with undeclared steroids or stimulants. This creates unexpected health risks and potential anti‑doping violations.

What is unclear / where evidence is limited

• Long‑term cardiovascular risk: While observational data link anabolic steroid use to heart disease, precise lifetime risk is difficult to quantify due to confounding factors.
• Mental health effects: Associations with aggression, mood disorders, and dependence are reported, but causality and individual vulnerability vary.
• “Stacking” multiple drugs: Many users combine substances. Controlled studies on combined regimens are lacking for ethical reasons.
• Newer agents (SARMs, peptide hormones): Selective androgen receptor modulators (SARMs) are marketed as “safer alternatives,” but human safety data are limited, and liver injury cases have been reported.
• Female‑specific outcomes: Research in women is more limited, particularly regarding long‑term reproductive and cardiovascular effects.

Overview of approaches

Performance enhancement strategies range from legal and medically supervised treatments to prohibited substances and unregulated compounds.

1. Medically indicated hormone therapy

Includes testosterone replacement, growth hormone therapy, or other endocrine treatments prescribed for diagnosed conditions. These require laboratory confirmation and ongoing monitoring according to clinical guidelines.

Typical dosing information for prescription medicines should only be followed as described in official product labeling and national regulatory guidance (e.g., FDA, EMA, MHRA websites).

2. Non‑medical use of prescription drugs

This includes anabolic steroids, EPO, stimulants, and other agents taken without a diagnosed deficiency. This practice is illegal in many jurisdictions and banned in competitive sports.

3. Over‑the‑counter supplements

Protein powders, creatine, beta‑alanine, and caffeine are legal and widely used. Among these, creatine monohydrate has relatively strong evidence for improving short bursts of high‑intensity performance when combined with training.

However, “natural anabolic boosters” and “legal steroids” often lack strong evidence and may carry contamination risks. Learn more in our evidence‑based supplement safety overview.

4. Non‑pharmacological performance optimization

• Structured training programs
• Sleep optimization
• Balanced nutrition with adequate protein
• Periodized recovery
• Psychological skills training

These approaches have strong evidence for improving performance and carry far fewer health risks. See also our sports medicine and recovery guide.

Evidence table

Practical recommendations

1. Consider health before performance

No short‑term gain outweighs permanent heart, liver, or hormonal damage. Competitive advantage achieved through banned substances can also result in suspension or legal consequences.

2. Seek medical evaluation for symptoms

If you experience low energy, reduced muscle mass, sexual dysfunction, or poor recovery, consult a healthcare professional for proper assessment rather than self‑medicating.

3. Be cautious with online products

Products marketed as “research chemicals,” “legal steroids,” or “rapid muscle builders” may be unregulated. Look for third‑party testing and discuss supplements with your clinician.

4. Prepare for your medical consultation

• List all substances and supplements you take
• Note training intensity and goals
• Report symptoms honestly (including mood changes)
• Ask about evidence, monitoring, and long‑term risks

5. Seek urgent care if you notice:

• Chest pain or shortness of breath
• Severe headaches or vision changes
• Yellowing of skin or eyes (possible liver injury)
• Severe mood swings or suicidal thoughts

For broader public health information, visit our preventive health resources page.

Sources

• World Anti‑Doping Agency (WADA) — Prohibited List and health consequences of doping
• U.S. National Institute on Drug Abuse (NIDA) — Anabolic Steroids and Other Appearance and Performance Enhancing Drugs (APEDs)
• Endocrine Society — Clinical Practice Guidelines on Testosterone Therapy
• U.S. Food and Drug Administration (FDA) — Information on hormone therapies and supplement safety
• International Olympic Committee (IOC) consensus statements on doping and athlete health