Herbal teas are often consumed for their physical or medicinal effects, especially for their stimulant, relaxant or sedative properties. The medicinal effects of certain herbs are discussed under herbalism. The medicinal benefits of specific herbs are often anecdotal or controversial, and in some countries (including the United States) makers of herbal teas are not allowed to make unsubstantiated claims about the medicinal effects of their products.

While most herbal teas are safe for regular consumption, some herbs have toxic or allergenic effects. Among the greatest causes of concern are:

Comfrey, which contains alkaloids that can cause permanent liver damage with chronic use.
Lobelia, which contains toxins similar in effect to nicotine.
Herbal teas can also have different effects from person to person, and this is further compounded by the problem of potential misidentification. The deadly foxglove, for example, can be mistaken for the much more benign (but still relatively hepatotoxic) comfrey.

The UK does not require herb teas to have any evidence concerning their efficacy, but does treat them technically as food products and require that they are safe for consumption.

yeah, tea not only has many health benefits and medicinal effects, it also has a function of relaxation. so drink more tea, be healthier!

What I often say is although liangcha - herbal teas/herbal medicine have been used for hundred's of centuries by people around the world
and have claimed to prevent or cure diseases, human beings are not the same as they were 100 or 1000 years ago they
they lived entirely different lifestyles than those of today. Therefore, for modern day human beings it is very difficult to
ascertain if these herbal treatments will in effect treat, cure or prevent any disease in any person today as they did
for hundred's of centuries.