Internally, the soothing effects of calendula have been used for stomach ulcers and inflammation. A sterile tea has also been applied in cases of conjunctivitis . 3 Calendula also contains carotenoids . Investigations into anticancer and antiviral actions of calendula are continuing. At this time insufficient evidence exists to recommend clinical use of calendula for cancer .
Evidence suggests the use of calendula for some viral infections.
However, the constituents responsible for these actions are not clear. At least 3 cups of tea are generally drunk per day. The tincture can be taken in water or tea. Home treatment for eye conditions is not recommended, as absolute sterility must be maintained. Except for the very rare person who is allergic to calendula and therefore should not use it, no side effects or interactions are known to exist.