Some limitations of herbal preparations:
(1) Herbs may contain naturally occurring toxins.
(2) Formulations may show wide intra and inter-lot variability.
(3) A single type of herb may show considerable variation depending on sunlight, season, moisture and other environmental factors.
(4) Keeping the preparations free of contaminants (purity) is difficult. These may be toxic (heavy metals, pesticides, mycotoxins) or nontoxic (cockroach parts, rodent feces, etc.)
(5) Commercial production of herbal products is largely unregulated and there is no requirement to demonstrate safety or efficacy.
In general:
(1) Do not take a large quantity of any one herbal preparation.
(2) Do not take any herb on a daily basis.
Investigate what you are taking:
(3) Buy only preparations when the plants are listed on the packet. (Preferrably buy products where there is an attempt to standardize the contents.)
(4) Do not take anything containing comfrey (or other known toxic herbs).
For women of reproductive age:
(5) Do not take herbs if pregnant or trying to become pregnant.
(6) Do not take herbs if nursing.
For infants:
(7) Do not give herbs to a baby.
