Ground cinnamon is very safe, the volatile oils can however cause a skin rash. Small amounts of coumarin can be found in Cassia and other cinnamons, generally only large doses of this compound will cause blood-thinning and liver problems, but it's something to be aware of. Also if you're planning on having surgery you should stop the use of cinnamon at least one week before going in as it has a blood thinning effect. You should also take care to monitor your blood sugar to avoid an unsafe drop in blood pressure.
As I mentioned earlier lavender is a very commonly used for its essential oil; the sedating, soothing and relaxing properties of the lavender oil make it great for headaches. You can add some to homemade soap or put a few drops into your bathtub. I like to use my humidifier and place a few drops into the medicine dish. This is a great way to get the lavender oil into the air and keeps your room more humid too. The lavender oil can also be massaged into the skin to relieve any sort of aches and pains you might have as well. Teas are also a great way get the benefits of lavender, when you're steeping a cup of tea just drop a few sprigs of lavender into the cup and let it steep as well.
CAM therapies include a wide variety of botanicals and nutritional products, such as dietary supplements, herbal supplements, and vitamins. Many of these "natural" products are considered to be safe because they are present in, or produced by, nature. However, that is not true in all cases. In addition, some may affect how well other medicines work in your body. For example, the herb St. John's wort, which some people use for depression, may cause certain anticancer drugs not to work as well as they should.
Toxin theory of cancer: In this idea, the body's metabolic processes are overwhelmed by normal, everyday byproducts. These byproducts, called "toxins", are said to build up in the cells and cause cancer and other diseases through a process sometimes called autointoxication or autotoxemia. Treatments following this approach are usually aimed at detoxification or body cleansing, such as enemas.