Plants that are said to have medicinal properties may be prepared for use in a variety of ways. One plant, known as Arnica montana, or simply arnica, can be put into a conveniently usable form by preparing a solution of its active compounds. These active substances can be extracted into alcohol in a form called a tincture, and one drop of this tincture is mixed with 99 drops of water to make a dilution that is 1 centismal (1c) strong. Repeating this process by taking a drop from the new solution and adding 99 drops of water creates increasingly lower dilutions. After 30 such dilutions, the result is a 30c solution, known in this case as arnica 30c.
Arnica 30c is sometimes found as a liquid solution, and it may also be put into salves, creams, or medicated lotions. The preparations may vary slightly as to their recommended use, but they are generally applied as topical remedies, meaning that they can be rubbed directly onto the skin. Taken other ways, such as orally, some arnica preparations have a likelihood of causing serious, even life-threatening side effects.
Information from the University of Maryland has stated that despite the possible danger from concentrated arnica, more diluted preparations like arnica 30c could be safe for internal consumption. Arnica montana contains compounds like helenalin that could be potentially dangerous when ingested in large amounts. Greatly diluted forms of the plant pose less danger, however. Helenalin is suspected by some researchers to be responsible for having effects like tumor-killing and anti-inflammatory activity.
Studies in the scientific journal, Cancer Chemotherapeutical Pharmaceuticals have identified compounds in Arnica montana that could have tumor-killing and anti-inflammatory properties. It is the anti-inflammatory nature of these compounds that are the primary reason for the use of arnica 30c in homeopathic remedies. Evidence compiled by the University of Maryland shows that insect bites and stings, bruises, muscle aches, rheumatism, and sprains are all conditions that could possibly respond to treatment with preparations containing arnica.
Other aches and pains involving muscle and bone are potential candidates for treatment with arnica 30c. Swiss studies at the Valens Clinic for Rheumatism investigated how men and women afflicted with osteoarthritis in the knee responded to preparations containing arnica. Stiffness and pain that was normally caused by the arthritis significantly decreased after a period of treatment with the medication. Similar pain caused by injury or strenuous activity might also respond to compounds that include this plant.