Food, plants, live animals, animal products and pharmaceuticals are almost always subject to extra sanitary or phytosanitary controls, because they carry biological risk in addition to ordinary commercial risk. Expect to need a health certificate, a phytosanitary certificate, or an import authorisation from a specific ministry, and expect physical inspection on arrival.
These categories are also the ones where enforcement tends to be strictest and penalties harshest, because the risk to public health is direct. If your product idea falls into one of these categories, budget more time for compliance research than for sourcing.