Generic medications are considered "essentially similar" to the originator, branded product, which is no longer protected by patent. This article reviews issues surrounding the use of generic alternatives. Legislative control of pharmaceuticals commenced in the US in 1906 with the Pure Drug and Cosmetics Act. The Hatch Waxman Act of 1984 allowed the marketing of generic medications with the Biologics Price Competition and Innovation Act of 2009 making access to the US market easier for generic compounds. In the EU, the 1965 Directive 65/65/EEC established prior approval before marketing of medicinal compounds with mutual recognition of medications, by Member States, following Directives 75/318/EEC and 75/319/EEC. Novel products must complete animal studies before Phases I -III human trials and must satisfy regulatory authorities before registration for human consumption. This entails up to 5,000 subject exposure with inherent great expense. They must then also pass economic consideration before formulary inclusion resulting in at least 5 years delay before full access to the market. Following expiry of patent, for branded product, generic (copy) drugs can be marketed. They must satisfy predetermined parameters and be within the 90% confidence interval of a comparative Area Under the Curve (AUC) and maximum concentration (Cmax) of 80 - 125% of parent compound [with the EMA stipulating 90- 111% for drugs with a narrow therapeutic index]. There has been evidence to suggest this is not always the case and the variation may be as great as - 70 - 140%. These studies are performed on less than 100 patients, thereby saving development costs and allowing marketing at greatly reduced pricing, thereby creating economic benefit. There has been recent report of falsified data on generic testing resulting in the suspension of 700 drugs, which may affect confidence in the process. Those who produce parent product may also produce generics, using the identical manufacturing facility but other manufacturers may also produce the generic with the same active ingredient but possibly different excipient within the formulation. There is evidence that use of generics can increase associated health costs with longer hospital stays, higher rate of hospitalisation and greater demand for ambulance services. Others dispute these findings, reaffirming equivalence and reporting a self-fulfilling expectation from doctors and patients who doubt generic compatibility. The rules regarding the dispensing of generic substitution are different in differing jurisdictions, which may, or may not, allow the pharmacist to substitute generic alternative with, or without, the prescriber's agreement. There has been report of branded Lamictal 8 actually being a generic alternative with presumed different excipient causing patient toxicity. There has also been report of a pharmacist ignoring patient and prescriber preference and attempting to coerce a patient to accept the generic alternative. Generic medications must satisfy criteria for bioequivalence with branded product but problems still may arise. Brand substitution is not without risk, necessitating informed consent, on the part of the end user patient, to respect autonomy and avoid litigation in negligence.