Drink plenty of filtered or bottled water
You will get dehydrated during your trip to niger at one point. at times it can be hard to find bottled water, but ask for "purewater" pronounced pure-wata that comes in sealed plastic bags for usually 25f 50f in some hard-to-reach places. you will also need to replenish your salts more frequently than you are accustomed.
Keep in mind that drinking alcohol is generally forbidden in Muslim culture, so take extra care to keep drunken inappropriate behavior behind closed doors and out of the public eye.
The national beer is called, appropriately, Biere Niger. The only other locally produced beer is a franchise of the French West-African Flag brewery. While taste is in the eye of the beerholder, Biere Niger is decent. Both are brewed in the same tank from the same ingredients with the slightest variation on how much reconstituted malt they put in each batch. All other beer, boxed wine, and hard liquor is imported.
In rare pockets of the capital you can find millet beer homebrew, brewed by Burkinabe immigrants. This is drunk out of calabash gourd bowls. Some compare the taste to a dry, unsweetened cider. See the Niamey section for directions.
Locally-made non-alcoholic drinks are delicious. Safety depends on the water quality: generally ok in the capital and NOT ok in rural areas. They are either sold by women out of their houses ask around, by young girls from trays on their heads, or by young boys pushing around coolers. These drinks include:
lemu-hari: a sweet lemony-gingery drink
bisap: a dark red kool-aid-type drink made from hibiscus leaves
apollo: a thick, pinkish-brownish drink made from the baobab fruit
degue: sweet yogurt with small millet balls like tapioca
To drink, you bite the corner off the bag.