Is it OK to Take Echinacea Daily?

Could you please tell me if the herb echinacea can be taken on a daily basis? Some people say is best taken on a short term basis.

Some herbalists advocate taking echinacea on an alternating schedule: one week on echinacea and the next week off. The idea is to prevent the body from developing insensitivities to echinacea. We are not aware of any research that supports this view. Many people are taking it daily as a general immuno-stimulant.
At the onset of cold and flu symptoms it should be taken in small frequent doses every 2-3 hours for the first 2-3 days. Similarly, when other infections occur – canker sores, psoriasis, wounds, etc. – echinacea can be taken more frequently. Once the condition clears, doses can be reduced back to normal levels or stopped altogether.
If you have concerns about taking echinacea continuously, consult your health care professional for advice.