There are lots of cases of doping in sports. One of the most known cases of doping in Spain is the case of David Meca, the famous swimmer. According to some magazines, in 1999, he took Nandrolone, which is an anabolic steroid. For taking this substance, he was penalized during 4 years
Looking on the Net, I find the following information about EPO, steroids and growth hormone:
EPO: Is a hormone that induces red blood cell production. It is used in treating anemia resulting from chronic kidney disease and myelodysplasia, from the treatment of cancer (chemotherapy and radiation), and from other critical illnesses (heart failure). EPO is associated with an increased risk of adverse cardiovascular complications in patients with kidney disease if it is used to increase hemoglobin levels above 13.0 g/dl. Moreover, early treatment with erythropoietin correlated with an increase in the risk of Retinopathy of prematurity in premature infants who had anemia of prematurity. Lots of cyclists were penalized for taking this substance.
Steroids: Is a type of organic compound that contains a specific arrangement of four rings that are joined to each other. Examples of steroids include cholesterol, testosterone, and the anti-inflammatory drug dexamethasone. Steroids exert a wide variety of effects mediated by slow genomic as well as by rapid nongenomic mechanisms. According the Information I could find on Internet, some well-known baseball players take this substance.
Growth hormone: Is a protein-based peptide hormone. It stimulates growth, cell reproduction and regeneration in humans and other animals. Growth hormone is used in medicine to treat children's growth disorders and adult growth hormone deficiency. In recent years, growth hormone replacement therapies have become popular in the battle against aging and obesity. Reported effects on GH-deficient patients (but not on healthy people) include decreased body fat, increased muscle mass, increased bone density, increased energy levels, improved skin tone and texture, increased sexual function and improved immune system function. Regular application of extra GH may show several negative side-effects such as joint swelling, joint pain, carpal tunnel syndrome, and an increased risk of diabetes. Other side effects can include less sleep needed after dosing.