What Is the Scientific Evidence for Oregon Grape?
Evidence from two double-blind, placebo-controlled studies and one comparative trial suggest that cream made from the herb Oregon grape may help reduce symptoms of psoriasis, although it does not seem to be as effective as standard medications. In a double-blind study published in 2006, two hundred people were given either a cream containing 10% Oregon grape extract or placebo twice a day for 3 months. 15 The results indicate that the people using Oregon grape experienced greater benefits than those in the placebo group, and the difference was statistically significant. The treatment was well tolerated, though in a few people it caused rash or burning sensation. Benefits were also seen in a double-blind, placebo-controlled study of 82 people with psoriasis. 7 However, the study design had a significant flaw: the treatment salve was darker in color than the placebo, possibly allowing participants to guess which was which. Another study found that dithranol, a conventional drug used to t
