The most effective drugs are free and without any side effects. These are biological drugs prescribed by the brain and synthesized by the endocrine, immune, GI, nervous, cardiovascular, renal, hepatic, and other systems. If one is in perfect health, these endogenously produced drugs are dispensed in exactly the right formula, dose, and schedule and are designed for the unique genetics of each individual. All of this occurs without any conscious awareness of the process. However, mind training can dramatically enhance this process during periods of illness, when some part of the endogenous pharmacy breaks down.
As a retired psychotherapist who worked exclusively with cancer, chronic pain, and chronic illness patients, I discovered that the best pain meds were the endogenous ones. Although self-hypnosis, biofeedback, various forms of meditation, and many other methods with proven efficacy exist, the sad story is that reimbursement is higher for expensive prescription drugs than it is for mind training in how to access the endogenous pharmacy.