|Dr. Simi, the Mexican dancing doctor.|
Pharmacies are very flexible here. With the exception of narcotics and antibiotics, most medications are available. It's not uncommon at all to find products that you'd never associate with a pharmacy, like candy, popsicles, chips, milk, batteries, etc.
Pharmacies come in lots of sizes. You can find a small storefront pharmacy with a clerk or you can go to Sanborns, a luxurious mix of a pharmacy, restaurant and mini-department store. Some offer well-known brand names and some offer generics, and then a few offer you both types of medications.
In addition to selling medications, many pharmacies have a small room called "consultorio." For a very low price, from 25 to 30 pesos (around $1.00 or $1.50 dollars), a doctor that's usually out of medical school will do a quick check-up, like looking at your throat, take your temperature and blood pressure, and the part of your body that is affected. He or she will also write you a prescription. With rare exceptions, the medications can be bought in the pharmacy. The most common of these pharmacies are called "Farmacias Similares" and you can usually identify them because their mascot Dr. Simi, is often seen dancing outside the storefronts.
Mexicans often consult a pharmacist because they it's a much cheaper option than paying a private doctor. Also, pharmacists have some experience with what medications are good for most common problems and their advice is free. The possibility of seeing a doctor for cheap right next door is another advantage.
Obviously, the other side of the coin is that very often people end up self-medicating themselves or with medications that might not be the best for their conditions. One of my friends had several infections: eye, stomach, jock itch as well as common symptoms, like fever and diarrhea. To make matters worse, he had a serious inflammation of the leg. After several treatments at these consultorios, he finally decided to see a private doctor, who immediately diagnosed a thrombosis and had him hospitalized for a week.
The moral of the story is: if you want something like an aspirin or for something very mild, like a cold or a stomachache, one of these pharmacies will do. For anything more serious, go see a real doctor, which is not that expensive for Americans anyway (about 300 or 400 pesos, which is approximately 23 to 30 dollars).
For more information on how to find a good doctor or specialist, I recommend Monica Rix Paxson's The English Speaker's Guide to Medical Care in Mexico.