Final answer:
Herb use is recommended to be approached with caution for pregnant or lactating women, infants, and children under six due to their vulnerability and the lack of definitive safety data.
Step-by-step explanation:
The use of herbs is generally recommended to be approached with caution for pregnant or lactating women, infants, and children younger than 6 years of age. This is because the bodies of these groups may be more vulnerable to the effects of various substances, and less is understood about the safety of many herbs during these critical developmental periods. Official guidance from agencies like the FDA, EPA, and CDC indicates that while people have different sensitivities, such as potential allergies to certain components, the overall safety of herbs for these groups is not fully established, and therefore, caution is advised.