A traditional East Asian medicine that has a couple of recent studies to back up its positive effects on the skin.
It seems to have potent anti-inflammatory activity, it's a mild antioxidant and also has strong anti-bacterial effect for acne causing bacteria, Propionibacterium acne.
Show me some proof
- Korean Chemical Engineering Research, Volume 48, Issue 6, 2010, pp.700-703, Anti-acne and Anti-atopic Dermatitis Effect of Plant Extracts Including Eucommia ulmoides Oliv and Phellodendron amurense
- Fitoterapia, Volume 72, Issue 3, March 2001, Pages 221–229, Topical anti-inflammatory activity of some Asian medicinal plants used in dermatological disorders