Antibióticos sin receta are actually a naturally formed, low molecular weight metabolic product of bacteria or fungi. Even in low concentrations, this metabolic product inhibits the growth of other microorganisms or kills them.
In Spain you can legally buy antibiotics without a prescription from your family doctor. You can do it online. The EU directive on patient mobility means that prescription drugs, such as antibiotics, can be ordered remotely from other EU countries.
There are online pharmacies where to place an order for antibiotics without a prescription, you have to complete a small online questionnaire, which is then examined by a real doctor abroad. An online prescription is then made and sent directly to an online pharmacy.