Everyone's body responds differently to beta blockers. For this reason it is important that each person experiment, under medical supervision, to find the ideal dosage for a performance situation. Similarly, it is important to take the beta blocker a few times and under different circumstances before a major performance to be sure the individual has no adverse reactions. Everyone, without exception, must obtain their beta blockers from a physician. It is a violation of federal law in the United States, and many other countries, to give prescription medications to someone other than the person for whom they were prescribed.
Beta blockers are prescription medications for good reason.
There are several conditions, such as slow heart rate, bronchial asthma, and heart failure, which can cause serious medical problems, even death, when taking this medication. In addition, you should know that some psychiatrists and psychologists feel that beta blockers ought only to be used in the context of psychological intervention, and only as a temporary measure. One reference lists 29 different uses, including high blood pressure, angina, irregular heart rhythms, migraines, prevention of a second heart attack, tremors, alcohol withdrawal, anxiety and glaucoma. In the United States, a physician can prescribe medications for uses not approved by the Food and Drug Administration, so long as there is scientific literature to support the use. Usually the pharmaceutical company involved will only research and develop a few uses to submit to the FDA to get the medication approved for marketing.