Old Medicine is a common item that is used to print/craft consumables such as Strong and Combat Stims to help recover health points in The Cycle: Frontier.
They only net 150 K-Marks and hence, are not worth selling. You will need a lot of Stims to survive against high-level enemies in high-tier areas. That is a good enough reason to hold on to as much Old Medicine as you can find.
Old Medicine is also an item that is attributed to the Osiris faction. You can get 2 faction points for each looted item.
The following guide will mark all of the locations where you can find Old Medicine in The Cycle: Frontier.
The Cycle: Frontier Old Medicine Locations
Old Medicine is commonly found in Medical Cases across all Tier areas. The starting Tier 1 Medical Cases have the highest spawn chance of 50%. The spawn chance keeps dropping as you venture into higher Tier areas.
Bright Sands Old Medicine Locations
Waterfall Lab in the northeast is an excellent farming location for Old Medicine. You will find an abundance of Medical Cases here.
You can also head to the Vaccine Labs on the east of the map for another haul. The Jungle Camp in the fast west and the northern forest areas of the Crashed Ship are good locations to farm Old Medicine as well.
Crescent Falls Old Medicine Locations
The immediate forest area north of Greens Prospect is a nice place to start looking for Old Medicine. Pinnacle Labs in the northeast corner of the map is probably the best location in Crescent Falls to loot Old Medicine.
Furthermore, you can also head to Favela in the south. The other named POIs have a chance of having the item as well. Old Medicine is pretty much scattered all over the map but in few quantities.