Performance enhancement drugs: what they are, what they do, and what they cost

Performance enhancement drugs sit in a strange place in modern medicine: some are legitimate, even life-changing therapies for well-defined diseases, while others are medications repurposed (or misused) to chase an edge in sport, the gym, the classroom, or the workplace. The same molecule can be “treatment” in one context and “doping” in another. That tension is exactly why this topic deserves a careful, non-dramatic explanation.

When people say “PEDs,” they often mean anabolic-androgenic steroids. In clinical practice, the landscape is broader. It includes hormones and hormone-like drugs (testosterone and other anabolic agents), respiratory medicines (beta-2 agonists), metabolic drugs (insulin, some thyroid hormones), stimulants (amphetamines, methylphenidate), and blood-oxygenation drugs (erythropoiesis-stimulating agents). A few are approved for narrow medical indications and monitored closely. Others are obtained online, taken in stacks, and mixed with supplements of unknown quality. Human biology is messy; the outcomes are rarely as clean as the marketing promises.

I’ve interviewed athletes who swear they “only used what a friend used.” I’ve also cared for patients who started with a perfectly reasonable prescription and then drifted into self-experimentation because they liked the way it felt. Those stories tend to begin with optimism and end with lab abnormalities, mood instability, injuries, or a scare that finally forces a pause.

This article walks through the main categories of performance enhancement drugs, their real medical uses, what is known about benefits and limits, and the risks that clinicians actually worry about. We’ll also address myths, common unsafe combinations, how these drugs work in plain language, and why the market for them keeps growing despite rules, testing, and periodic scandals. If you want a primer on the difference between regulated therapy and risky self-medication, start with how prescription medicines are monitored.

Medical applications

There is no single “performance enhancement drug” with one label and one indication. This is a category. So the most honest way to discuss medical applications is to describe the major drug classes that get pulled into performance culture and to separate approved medical use from non-medical performance use.

2.1 Primary indication: treating disease states that impair performance

Primary use (category-level): treating diagnosable conditions that reduce strength, endurance, attention, oxygen delivery, or recovery. In medicine, the goal is not “extra performance.” The goal is restoring function, preventing complications, and improving quality of life.

Here are the most common clinical lanes where drugs later labeled as “performance enhancers” show up:

Testosterone (generic name: testosterone; therapeutic class: androgen/anabolic hormone) is prescribed for male hypogonadism when there is consistent biochemical evidence and compatible symptoms. In the clinic, the conversation is about sexual function, bone density, anemia, body composition, and mood—not turning someone into a superhero. Patients tell me they expect “instant energy.” The reality is slower and more nuanced, and it does not fix sleep apnea, depression, overtraining, or a chaotic diet.
Erythropoiesis-stimulating agents (generic names include epoetin alfa and darbepoetin alfa; therapeutic class: erythropoiesis-stimulating agents) are used for specific forms of anemia, such as anemia associated with chronic kidney disease and certain chemotherapy-related settings. Their medical aim is reducing transfusion needs and improving anemia-related symptoms. Outside medicine, they are misused to raise red blood cell mass for endurance—an entirely different risk-benefit equation.
Stimulants (generic names: amphetamine salts, methylphenidate; therapeutic class: central nervous system stimulants) are prescribed for ADHD and narcolepsy. In a properly evaluated patient, they can improve attention and reduce sleep attacks. They are not a safe “focus hack” for healthy people, and they do not replace sleep. On a daily basis I notice that the people chasing productivity often underestimate how quickly anxiety, insomnia, and blood pressure problems can show up.
Beta-2 agonists (generic names: albuterol/salbutamol, formoterol; therapeutic class: bronchodilators) are core therapies for asthma and COPD. For someone with exercise-induced bronchoconstriction, appropriate inhaled therapy restores breathing capacity during training. That is very different from using high doses or systemic forms in an attempt to alter body composition or stamina.
Insulin (generic name: insulin; therapeutic class: peptide hormone) is essential for type 1 diabetes and used in many cases of type 2 diabetes. In bodybuilding circles it’s sometimes abused for “nutrient partitioning.” In hospital medicine, insulin is a high-alert medication because hypoglycemia can injure the brain or kill. That contrast should make anyone pause.

In other words: the medical version of “performance” is often just normal function. Walking up stairs without stopping. Finishing a workday without crashing. Having stable blood counts. Sleeping through the night. Those are wins that don’t make headlines.

2.2 Approved secondary uses (selected examples)

Several drugs pulled into performance culture have legitimate additional indications. A few examples that clinicians see regularly:

Testosterone has specific uses beyond classic hypogonadism in tightly defined scenarios (for example, certain delayed puberty contexts under specialist care). The boundaries matter because testosterone affects fertility, hematocrit, lipids, and prostate-related monitoring.
Epoetin alfa/darbepoetin alfa are used in multiple anemia contexts, but the details are not interchangeable. The target hemoglobin range and monitoring approach are designed to reduce harm, not maximize oxygen carrying capacity.
Albuterol (salbutamol) is used for acute bronchospasm relief and prevention of exercise-induced symptoms. Used correctly, it’s a rescue medication. Used as a “pre-workout,” it becomes a different story.

I often see confusion here: people assume that because a drug is FDA-approved, any use is “safe if you’re careful.” Approval is for specific indications, doses, and populations, with known monitoring plans. Outside that box, risk becomes harder to predict.

2.3 Off-label uses (clearly labeled)

Off-label means a clinician prescribes an approved drug for a non-approved indication, based on judgment and evidence that may be limited or evolving. Off-label prescribing is common in medicine, but it is not a free pass for experimentation.

Examples that intersect with performance discussions include:

Clomiphene citrate (generic name: clomiphene; therapeutic class: selective estrogen receptor modulator) is approved for ovulatory dysfunction in women, yet it is sometimes prescribed off-label in men for certain infertility and endocrine scenarios. In performance circles it’s discussed as a way to manipulate hormones after steroid use. Clinically, the goals are fertility and endocrine stability, not muscle gain.
Modafinil/armodafinil (generic names: modafinil, armodafinil; therapeutic class: wakefulness-promoting agents) are approved for narcolepsy and related sleep disorders. Off-label use for fatigue is sometimes discussed, but fatigue has many causes—sleep debt, depression, anemia, thyroid disease, overtraining—and a pill can mask the signal while the underlying problem worsens.
Beta-blockers (therapeutic class: beta-adrenergic antagonists) are prescribed for hypertension, arrhythmias, and migraine prevention. They are also misused in precision sports to reduce tremor and performance anxiety. Clinically, they can worsen asthma and affect exercise tolerance, which surprises people who assume “calmer equals better.”

When off-label prescribing is responsible, it includes documentation, monitoring, and a clear endpoint. The internet version tends to skip all three.

2.4 Experimental / emerging uses

Performance culture loves “the next thing.” Medicine moves slower, for good reasons. A few areas that keep resurfacing:

Myostatin inhibitors and other muscle-growth pathway modulators have been explored for muscle-wasting diseases. Early signals and animal data do not automatically translate into safe human performance enhancement. The body tends to punish shortcuts with tendon injuries, cardiac remodeling, or metabolic surprises.
HIF pathway modulators (drugs that influence hypoxia signaling) have legitimate research and clinical roles in anemia management in some regions. Their appeal for endurance is obvious, and so are the concerns about clot risk and long-term cardiovascular effects.
Gene doping concepts are discussed more than they are documented in real-world sport. The science is real; the predictable safety profile is not. When regulation lags behind innovation, athletes become the test subjects. That is not a compliment.

If you want a grounded overview of how evidence matures from early studies to clinical consensus, see what “good evidence” looks like in medicine.

Risks and side effects

Risk depends on the specific drug, dose, route, duration, and the person taking it. That sounds obvious, yet it’s the part most online advice ignores. In clinic, the red flags are predictable: hidden heart disease, untreated sleep apnea, clotting history, psychiatric vulnerability, and polypharmacy. Add dehydration, intense training, and stimulants, and you get a recipe for the emergency department.

3.1 Common side effects

Common adverse effects vary by class, but patterns show up repeatedly:

Anabolic-androgenic steroids / testosterone-related agents: acne, oily skin, hair loss in predisposed individuals, fluid retention, irritability, and changes in libido. Lab changes can include increased hematocrit and unfavorable lipid shifts.
Stimulants: decreased appetite, insomnia, dry mouth, jitteriness, increased heart rate, and anxiety. People are often shocked by how quickly sleep quality collapses, and then they chase that with sedatives or alcohol.
Beta-2 agonists: tremor, palpitations, nervousness, and headaches. Higher exposures raise the chance of rhythm issues, especially with other stimulants.
Erythropoiesis-stimulating agents: injection-site reactions, blood pressure elevation, and flu-like symptoms. The bigger concern is what happens when hemoglobin is pushed beyond safe targets.
Thyroid hormones (levothyroxine/liothyronine): heat intolerance, sweating, tremor, diarrhea, and anxiety when used inappropriately. People chasing fat loss often interpret these as “it’s working.” Clinically, they are signs of iatrogenic hyperthyroidism.

Many of these effects are not dramatic. They’re just persistent. Patients describe feeling “wired but tired,” snapping at family, or noticing their resting heart rate creeping up. Those are not badges of commitment.

3.2 Serious adverse effects

Serious harms are less common than acne or insomnia, but they are the reason clinicians are cautious.

Cardiovascular events: hypertension, arrhythmias, cardiomyopathy, heart attack, and stroke have been associated with multiple classes when misused, especially stimulants and anabolic agents. Risk rises with underlying heart disease, dehydration, and concurrent stimulant use.
Thromboembolic complications: increasing red blood cell mass or thickening blood can raise clot risk. That includes pulmonary embolism and stroke. Endurance athletes sometimes interpret “thicker blood” as “more oxygen.” The body interprets it as “harder to pump.”
Liver injury: certain oral anabolic steroids are particularly associated with liver toxicity and cholestasis. Add alcohol, and the margin of safety narrows fast.
Endocrine and reproductive effects: testicular atrophy, infertility, menstrual disruption, and long-lasting suppression of the hypothalamic-pituitary-gonadal axis can occur with anabolic steroid misuse. I’ve had conversations with young men who assumed fertility would “bounce back” on schedule. Sometimes it doesn’t.
Psychiatric effects: mood swings, aggression, panic, and depressive crashes are reported with several drug classes, especially when cycling on and off. The mental side is often minimized until relationships or work start breaking.
Hypoglycemia (insulin misuse): confusion, seizures, loss of consciousness, and death are possible. There is no “toughing it out” through severe hypoglycemia.

Urgent symptoms that warrant immediate medical evaluation include chest pain, fainting, severe shortness of breath, one-sided weakness, sudden severe headache, new confusion, black/tarry stools, yellowing of the skin/eyes, or a sustained rapid/irregular heartbeat.

3.3 Contraindications and interactions

Because “performance enhancement drugs” are a category, contraindications are best understood as high-risk pairings between drug class and medical history.

Known heart disease, uncontrolled hypertension, or arrhythmia history: stimulants, high-dose thyroid hormone, and beta-agonist misuse increase risk. Even “mild” palpitations can be a warning shot.
Clotting history or high hematocrit: erythropoiesis-stimulating agents and androgenic drugs that raise hematocrit can be dangerous without careful monitoring.
Sleep apnea: untreated sleep apnea plus testosterone therapy is a common clinical tension point, because sleep apnea can worsen and cardiovascular risk can rise.
Psychiatric vulnerability: stimulants and anabolic agents can destabilize anxiety, bipolar disorder, or impulse control problems.

Interactions are often the hidden problem. Stimulants combined with decongestants, high-caffeine “pre-workouts,” or illicit stimulants can push heart rate and blood pressure into unsafe territory. Alcohol plus oral anabolic steroids increases liver strain. Multiple agents that raise sympathetic tone (stimulants + beta-agonists + thyroid hormone) can turn a routine workout into a cardiac stress test. For a practical overview of medication interaction basics, see how drug interactions are assessed.

Beyond medicine: misuse, myths, and public misconceptions

Misuse thrives in the gap between what people want (fast, visible change) and what physiology allows (slow adaptation, trade-offs, side effects). The internet fills that gap with certainty. Real medicine rarely speaks in absolutes, which makes it less catchy and more reliable.

4.1 Recreational or non-medical use

Non-medical use tends to cluster around a few goals: more muscle, less fat, more endurance, more focus, or faster recovery. The pattern I hear again and again is “I’m not competing, so it’s not doping.” That’s a moral argument, not a medical one.

Expectations are often inflated because early changes can be dramatic: water shifts, glycogen changes, appetite suppression, or the simple confidence boost that comes from feeling “on something.” Then the bill arrives—sleep disruption, tendon pain, blood pressure rise, mood volatility, or lab abnormalities that don’t match how “fine” the person feels.

4.2 Unsafe combinations

If there is one theme that scares clinicians, it’s stacking. People combine agents with overlapping risks and then add training stress, dehydration, and sometimes alcohol.

Stimulants + caffeine + decongestants: additive sympathetic stimulation, higher arrhythmia risk, panic, and severe insomnia.
Anabolic agents + erythropoiesis-stimulating agents: compounding effects on blood viscosity and blood pressure, raising clot and stroke risk.
Thyroid hormone + stimulants: a common “cutting” idea that can provoke tachycardia, anxiety, and dangerous heat intolerance during training.
Insulin + intense training: hypoglycemia risk becomes harder to predict, especially when meals are inconsistent or vomiting/illness occurs.

People ask, “How do I do it safely?” As a physician, I can’t pretend there is a safe DIY pathway here. There are only risk gradients, and online advice routinely understates them.

4.3 Myths and misinformation

Myth: “If it’s prescribed, it’s harmless.” Prescription status reflects regulated manufacturing and defined indications, not universal safety for any goal.
Myth: “Natural supplements are safer than drugs.” Some supplements are benign; others are contaminated, mislabeled, or pharmacologically active. “Natural” is a marketing word, not a pharmacology category.
Myth: “Blood thickening equals better endurance.” Oxygen delivery depends on cardiac output, vessel health, and blood properties. Thick blood can reduce flow and raise clot risk.
Myth: “Post-cycle tricks guarantee recovery.” Endocrine recovery is variable and can be prolonged. Fertility and mood effects can linger.

Patients sometimes laugh and say, “So you’re telling me the body keeps receipts?” Yes. It does.

Mechanism of action (in plain but accurate terms)

Performance enhancement drugs work by shifting one or more limiting steps in human physiology. The body’s limits are not just “motivation.” They’re oxygen delivery, energy availability, muscle protein turnover, neuromuscular signaling, and perception of effort. Different drug classes target different bottlenecks.

Anabolic-androgenic agents (testosterone and related compounds) bind to androgen receptors in muscle and other tissues. That receptor activation changes gene expression and protein synthesis, tilting the balance toward muscle growth and faster recovery from training stress. The same receptor activity also affects skin oil glands, hair follicles, the prostate, and the brain—hence acne, hair changes, and mood effects. Negative feedback to the hypothalamus and pituitary reduces natural gonadotropin signaling, which is why testicular function and fertility can be disrupted.

Erythropoiesis-stimulating agents act on the bone marrow to increase red blood cell production. More red blood cells can increase oxygen-carrying capacity, which is appealing for endurance. The trade-off is thicker blood and higher cardiovascular strain, especially when hemoglobin rises beyond medically targeted ranges.

Stimulants increase synaptic signaling of neurotransmitters such as dopamine and norepinephrine (the exact mechanism varies by drug). That can improve wakefulness and attention in ADHD or narcolepsy. The same pathway increases heart rate, blood pressure, and anxiety in many people, and it can blunt appetite and sleep—two pillars of recovery.

Beta-2 agonists relax airway smooth muscle, opening the bronchi and improving airflow in asthma. At higher exposures, they also stimulate beta receptors in the heart and skeletal muscle, producing tremor and palpitations. That “revved” feeling is not the same as improved conditioning.

Historical journey

6.1 Discovery and development

The history of performance enhancement drugs is really the history of modern pharmacology colliding with human competitiveness. Testosterone was isolated and synthesized in the early 20th century, and its anabolic effects were quickly recognized. What began as endocrine science and legitimate therapy for deficiency states became, in parallel, a tool for physique and strength enhancement. Patients sometimes ask me, half-joking, “So this was always going to happen, right?” Once you can amplify a biological pathway, someone will try to use it for advantage.

Erythropoiesis-stimulating agents emerged from advances in biotechnology and recombinant DNA techniques, designed to treat serious anemia. Their misuse in endurance sports became a defining controversy of late 20th-century and early 21st-century competition. Stimulants have an even longer story, with medical uses for narcolepsy and ADHD alongside well-known patterns of misuse for alertness and appetite suppression.

6.2 Regulatory milestones

Regulatory agencies approved many of these drugs for narrow medical indications with specific monitoring requirements. Sports governing bodies, in turn, developed banned substance lists and testing programs as misuse became widespread. The regulatory logic in medicine is patient safety and clinical benefit. The logic in sport is fairness and harm reduction. Those goals overlap, but they are not identical, which is why debates about “therapeutic use exemptions” can get heated.

6.3 Market evolution and generics

Over time, brand-name products and generics expanded access for legitimate patients. At the same time, underground markets grew: diverted prescriptions, counterfeit vials, and “research chemicals” sold with a wink. In my experience, the market’s most dangerous feature is not price—it’s uncertainty. You cannot manage risk when you don’t know what you’re taking.

Society, access, and real-world use

Performance enhancement drugs are not just a medical topic; they’re a social one. They reflect cultural pressure, body ideals, and the way social media compresses timelines. A decade of training is hard to photograph. A rapid transformation sells.

7.1 Public awareness and stigma

Some medications—testosterone therapy, ADHD stimulants, asthma inhalers—are widely discussed, and that visibility cuts both ways. Public awareness can reduce stigma and encourage people with real symptoms to seek evaluation. It also creates a shortcut mentality: “If my friend got it, I should get it.” I often see patients arrive already convinced of the diagnosis because they recognize a few symptoms from a podcast. Sometimes they’re right. Often they’re missing the bigger differential diagnosis.

Stigma also pushes use underground. When people fear judgment, they hide side effects, skip monitoring, and avoid disclosing drug use to clinicians. That silence is dangerous, particularly before surgery, during acute illness, or when starting new medications.

7.2 Counterfeit products and online pharmacy risks

Counterfeit and substandard products are a practical, everyday risk in the performance space. Online sellers can offer “brand-name” hormones, peptides, or stimulants that contain the wrong dose, the wrong compound, or contaminants. Even when the active ingredient is present, sterility and storage conditions are unknown. Infections from non-sterile injections are not theoretical; they show up as abscesses, cellulitis, and occasionally bloodstream infections.

Another issue is mislabeling of “supplements” that contain undeclared pharmaceuticals. People think they are taking a benign fat burner or sexual enhancement product and end up ingesting stimulants, PDE5 inhibitors, or thyroid-active substances. If you want a broader safety framework, how to evaluate supplement claims is a useful starting point.

7.3 Generic availability and affordability

Generics generally improve affordability and access for patients with legitimate indications. Clinically, a well-manufactured generic is expected to perform similarly to the brand for the approved use. The bigger real-world barrier is not always cost; it’s appropriate diagnosis, follow-up, and monitoring. People sometimes focus on the product and forget the process. The process is where safety lives.

7.4 Regional access models (OTC / prescription / pharmacist-led)

Access rules vary widely by country and sometimes by state or province. Some medications are strictly prescription-only; others are pharmacist-dispensed; a few are available over the counter in limited formulations. Sports rules add another layer: a drug can be legal to possess and still prohibited in competition. If you travel, compete, or switch healthcare systems, do not assume last year’s rules apply this year.

One last real-world point: many harms come from secrecy. If a clinician doesn’t know what a patient is taking, they can’t interpret labs correctly, can’t anticipate interactions, and can’t recognize a drug-related symptom pattern. Patients sometimes worry, “Will you judge me?” Most clinicians are far more focused on preventing a stroke than scoring moral points.

Conclusion

Performance enhancement drugs include a wide range of medications with legitimate roles in treating anemia, asthma, ADHD, endocrine disorders, and other conditions that genuinely limit function. In those settings, they can restore health and reduce complications. Outside those indications, the same pharmacology becomes riskier: benefits are often overstated, side effects are underplayed, and stacking multiplies uncertainty.

If there’s a single thread running through all of this, it’s that physiology trades in compromises. Boost one pathway and you stress another. The safest “performance plan” is still boring: sleep, progressive training, nutrition, and honest medical evaluation when symptoms appear. Drugs are tools, not shortcuts, and the wrong tool can do real damage.

Informational disclaimer: This article is for general education and does not replace individualized medical advice, diagnosis, or treatment. If you are considering or already using any medication or supplement for performance, discuss it with a licensed healthcare professional who can review your medical history, current medications, and personal risk factors.