Oregano is an herb that's commonly used in cooking. Oil extracted from its leaves has a long history of medicinal uses.
Over the centuries, it has been used to treat a variety of ailments, including snake and spider bites, respiratory troubles, and menstruation problems. Today, it is marketed for the treatment of a long list of health conditions.
Chlorella may make it harder for warfarin and other blood-thinning drugs to work.
Some chlorella supplements may contain iodine, so people with thyroid conditions may want to avoid taking chlorella.
Always tell your doctor about any supplements you are taking, including natural ones and those bought without a prescription. That way, your doctor can check on any potential side effects or interactions with any medications.