In the United States, the three primary uses of chamomile are for inducing sleep, settling an upset stomach and soothing skin inflammation, although there has been little research on the herb to determine its efficacy. Both German chamomile and Roman chamomile are available, and although the two plants differ, their flowers have similar effects, according to Drugs.com.
As of 2014, German chamomile has been the subject of more research studies than the Roman variety. In Germany, chamomile has government approval for topical use to reduce inflammation of the skin, to fight bacterial infection and to reduce stomach cramps. However, in the United States, chamomile is classed as a supplement, and the FDA regulates supplements differently than it does drugs. According to WebMD, the FDA allows the sale of supplements with limited research on whether or how they work.
While both types of chamomile are generally well-tolerated, WebMD reports that they sometimes cause allergic reactions, especially in individuals who are allergic to ragweed or other members of the daisy family. Supplements have the potential to interact with certain medications to make a condition worse. A patient using supplements needs to inform his doctor before the doctor prescribes any new medication. Drugs.com indicates that some patients experience severe reactions to the herb, including contact dermatitis and anaphylactic shock.