Hydra

Hydra is a consumable item in Fallout: New Vegas.

Background
Hydra is a drug developed from Antivenom. Due to the Legion's disapproval of using modern medicine, some Legionaries attempted to develop a different means to help them heal damaged limbs. To do that, they combined Cave Fungus, Nightstalker blood and the poison from a Radscorpion poison gland with Antivenom before use, developing Hydra, a curative agent which both anesthetizes and restores crippled limbs over time.

Despite its origins in the Legion, this drug has since seen extensive use throughout the entire Mojave Wasteland, including NCR field hospitals. Excessive use causes dilated eyes, an increased heart rate and blood pressure, massive sweating and other typical symptoms of drug abuse.

All Hydra in-game use the bottle of a brand of fruit drink called Supa Yum! to hold its contents.

Characteristics
Like a Doctor's Bag, Hydra is used to restore health to crippled limbs making it especially useful in hardcore mode where Stimpaks or sleeping in a bed you don't own (from having rented or being given the room) won't heal these injuries. It has the advantage over Doctor's Bags in that it is weightless and it will continue to slowly heal the crippled wounds over 60 seconds. In a tough fight where you might receive crippling wounds several times a single dose of Hydra can heal them as you receive them. As a bonus, Hydra also benefits from the Chemist and Day Tripper perks.

The down side is that Hydra carries a 10% risk of addiction. If this happens you'll suffer a negative hit to your statistics (-3 Endurance) unless you either use more Hydra or Fixer (to provide temporary relief from the symptoms of withdrawal) or have a doctor cure you.

Locations

 * With and a positive reputation with the Great Khans, you can teach Jack the recipe for Hydra, and he will then stock it for sale at his shop.
 * There are two doses on a desk at the Nevada Highway Patrol station.
 * Sometimes found on dead Powder Gangers.
 * Two are found at the end of Silver Peak Mine.
 * One is found in a bathtub at the bottom of The Devil's Gullet.
 * One can be found in Prospector's Den, somewhere around the generator.
 * One can be found near a bundle of campers in Camp Searchlight.
 * One lies in a sunken shipwreck northeast of Boulder Beach campground and south of the scavenger platform.

Behind the scenes
The origin of the name is of the Lernaean Hydra of the Second Labor of Heracles.