Medicine - one which goes through natural route or injection, does it's work through Rasa, Virya, Vipak, prabhava, and then leaves the body through urine, feces, sweat, and breath without creating any side effects.
Note that modern medicine does not fit this Ayurvedic definition.
Hence, iatrogenic diseases are created through drugs and are the third leading cause of death according to the American Medical Association. Iatrogenic is a new “branch” of modern medicine.
Ayurveda uses individualized medicines (remedies) that are particular to the unique manifestation of vata - pitta - kapha at the specific stages of samprapti
Herbs - what is present in the Human is present in the plants in an altered form. According to Ayurveda, every plant has Mind, body, soul, consciousness (vijnana). Every herb has Ojas, Tejas, and Prana.
Plants are living breathing sensing beings, that have intelligence. Plants love Human beings.
Food has long sustained action, where as herbs on the other hand, have a shorter acting time.
The Sanskrit word Samvetsar = potency of herbs once powdered is 1 year maximum.
Sam = total, var = life force, sar = spreading.
Herbs create changes in Ojas-Tejas-Prana, in living and nonliving things.
One year after being harvested, the life force diminishes.
It is good to use glass or clay pot for storing and cooking-decocting-boiling herbs.
The intelligence of herbs implies a multi-dimensional action
Every herb has intelligence; and that intelligence operates through the Guna, Rasa, Virya, Vipak, and Prabhava.
Every herb has its field of action, specific taste (rasa), heating (usher) or cooling (shita) energy (vireo), and post-digestive effect (vipaka).
Herbs are intelligent. That is to say that they go to site of the lesion. Herbs are like cellular food.
Nature's Healing Herbs if used correctly in the proper dosage for the proper situation have no side effects . On the other hand, Human created modern drug always have some side effects - sometimes large side effects, sometimes small.
In Ayurveda, the accuracy of treatment depends on the practitioner diagnosing and treating according to:
1. The unique Vata - Pitta - Kapha of the Prakruti (genetic karmic constitution),
2. The Vikruti (specific guna-based imbalance of Vata - Pitta - Kapha doshas), and
3. The Samprapti - the six stages of Vata - Pitta - Kapha dosha disease process etiology - pathology.
The energy in the plant is the energy in the person and vice-versa. Unified as one.
Ayurveda would say that the same aspirin given by three different doctors will have a slightly different placebo effect.
Prabhava is the dynamic action of the herb that makes it unique beyond its specific Rasa, Virya, and Vipak.
The moment you touch the plant, the Prabhava changes in a subtle way, although its basic Prabhava still exists.
There are Mantras that can enhance the Prabhava of a plant.
In a person, what makes them unique beyond their Prakruti - vikruti is their personality (pudgala). In a similar way, for God or Buddha, what makes God or Buddha unique beyond our concept or image of God ot Buddha, includes tGrace or Punya (merit virtue blessings).
Ayurveda classifies herbs according to Doshas, Dhatus, organs, Srotamsi, and Samprapti.