Trade in ivory is prohibited by nearly all countries in the world, with hefty penalties and even jail time for offenders. Many animal products (some commonly found in fetish markets) are also banned by western countries, such as tortoise shells, tusks of any animal, or any part of or item made with an endangered species. Some African countries keen on conservation will prosecute all violators to the fullest extent of the law...so be careful when purchasing animal products unless you want to spend years in an African prison. Keep in mind that even if an item may be exported from an African country it may be illegal to import into a Western country; both the EU and US have strict laws on importing animal products in the name of conservation.
Some medications which may be purchased without a prescription in Western countries or parts of Africa may contain ingredients considered illegal narcotics or controlled substances in some countries. In particular, diphenhydramine is a "controlled substance" in Zambia and several Americans have been fined and jailed on drug-trafficking charges for possession the over-the-counter allergy medicine Benadryl (elsewhere called Dimedrol) and the pain reliever Advil PM whose main active ingredient is diphenhydramine.
Drug trafficking is as common an offense as in most Western countries. The list of what substances are considered drugs varies from country to country. Beware khat which is readily grown and consumed in Ethiopia and the Horn of Africa is considered a drug in most other African countries. Organized drug trafficking is a major problem in Guinea, & Guinea-Bissau en route from South America to Europe.
As with most countries, check local laws concerning antiquities before trying to leave the country with anything that appears to be over 100 years old.