Ant nectar is a naturally occurring substance secreted by giant ants. When consumed the nectar grants +4 Strength, but inflicts a penalty of -2 to Charisma and Intelligence. If taken in excess, you can get addicted to it, though the chance of addiction is very small. Taking 7 doses in a short amount of time is relatively safe, however the eighth dose will have a 100% addiction chance due to the usage monitor effect.
pc Ant nectar addiction used to be incurable due to a bug, but this was fixed in Fallout: New Vegas patch 184.108.40.206x. The console command Player.RemoveSpell 0006DC6E will immediately remove the addiction on the player version. [verified]