Medications

Medications are substances used to diagnose, treat, prevent, or modify physiological functions in humans and animals. They include prescription medicines, over-the-counter drugs, and biologics such as vaccines. They differ from dietary supplements and cosmetics in regulatory oversight and demonstrated safety and efficacy.

Prescriptions require clinician authorization; OTC medicines are sold without a prescription. Biologics include vaccines and therapeutic proteins and often require special handling. Medications come in forms such as tablets, capsules, liquids, injections, inhalers, patches, and topical creams.

Most medications act by targeting receptors, enzymes, or other biological pathways. Pharmacokinetics describes how the body absorbs, distributes, metabolizes, and excretes a drug, shaping onset and duration of effect.

Regulatory authorities evaluate safety and efficacy before market release (for example, FDA, EMA). Labels include indications, dosing, warnings, and adverse effects. Ongoing pharmacovigilance monitors post-market safety and interactions.

Safe use requires correct dosing, adherence, and storage. Many medicines interact with foods, other drugs, or health conditions, so professional guidance is important for certain populations.

Drug development typically proceeds from discovery and preclinical testing to human clinical trials (phases I–III) and regulatory review, with post-marketing studies continuing safety assessment.

Access and equity influence who receives appropriate medications. Advances in pharmacogenomics aim to tailor therapy to individual genetic profiles.