Hypericum perforatum extracts as potential antidepressants.

Extracts of Hypericum perforatum have been used in the treatment of mild to moderate depression for many years in Europe. More recently, these extracts have become available in the USA as dietary supplements and have been popularly used to improve mood. In support of this practice, data from several controlled clinical studies suggest that Hypericum perforatum is better than placebo and as effective as established antidepressant drugs. These data have, however, several limitations that should temper our enthusiasm and argue for more research before accepting Hypericum perforatum extracts into our pharmacopoeia of established antidepressants. Extant data on the possible effects of Hypericum perforatum extracts in depression are here critically reviewed and plans for further research presented.