Further to when NOT to take certain herbs and supplements, part 1, here are some more conditions which preclude the use of some herbs :
Cayenne pepper is sometimes taken to treat some minor digestive problems, as it is thought that Capsaicin, the active ingredient, may have a protective effect on the lining of the stomach. some of the minor conditions it is used for include loss of appetite and gas. It is also sometimes used to improve circulation. But individuals who suffer from ulcers, gastritis or esophagitis should keep away from using it, as should ashmatics who are on theophylline (taken together, Capsaicin can increase the concentration of theophylline in the blood to dangerous levels by increasing its absorption from the stomach.
Papaya leaves are taken for their Papain content; an enzyme that breaks down proteins and therefore can be used for minor digestive problems such as nausea and bloating, especially those that result from eating a protein-rich meal. But it should not be taken by anyone on blood-thinners such as warfarin or heparin, anyone who has gastric ulcers or pregnant women, as it can cause uterine bleeding and miscarriage.
Camphor is found in such common products as Vicks VapoRub as an 11% solution and no higher, as it is potentially toxic in higher concentrations. The ointment is used on the skin to relieve sore muscles, whereas inhaling the vapor can help relieve chest congestion. Camphor should not be used by pregnant women without consulting a physician as it may affect the unborn foetus or cause uterine bleeding or miscarriage. It may also adversely affect very young newborns, and should therefore not be administered to them without consulting a health care provider.
Eucalyptus oil is used to treat chest congestion, sore muscles and joint pain. It should never be taken orally or internally as it is poisonous when taken that way, and it should be avoided by pregnant or nursing women.
Ginkgo is widely used to improve mental function, circulation, memory and sometimes, in appropriate patients, to treat asthma and other health problems. But if a person is on blood thinners like warfarin and heparin it should be avoided.