The spray's design has changed little over the entire course of the Resident Evil series. It's a silver spray can with a light green label.
Resident Evil (2002)
A First Aid Spray will completely heal the player character. Sometimes they can be found inside of First Aid Boxes.
- Examine: First Aid Spray
"A medicinal spray that can heal wounds completely."
The First Aid Spray is first and foremostly a healing item. It is one of the most effective means of raising a characters Health back to full. However, it cannot cure the Poison status effect. Use of First Aid Sprays in these games can negatively affect the player's final rank for game completion, though other healing methods do not.
- Examine: First-Aid Spray (Resident Evil 0)
"Used to fully restore health."
Resident Evil Survivor
"This spray will fully recover your vitality."
Outbreak and Outbreak File #2
Unlike other games in the series, the First Aid Spray will only cure 3000HP of a character's health (although it cures most of the characters completely, however some 'extra' characters possess more than 3000HP) and it will stop the spread of the virus -of any character- for about 30 seconds. It cannot cure the infection, however. Like previous games it also does nothing to stop Poison although it cures "Bleeding" status.
Starting from the Outbreak series onward, the First Aid Spray is able to heal multiple characters who stay close together by equipping it as a weapon and spraying it on allies. However, this will also ruin the NO WEAPON feat of the player.
Resident Evil 4
"Completely restores health."
In Resident Evil 4, the First Aid Spray is a full heal item. Several of them can be found throughout the game. They can also be bought, although the Merchant will restrict his stocks if Leon has more than one full health restoring item (G+G+G, R+G or R+G+Y, Gold Chicken Egg, and Black Bass (L)). Each costs 5,000₧ and the Merchant has a max stock of 2. Alternatively, they can be sold for 2,500₧. Each spray takes up 1x2 spaces of inventory.
Leon starts the main game with a First Aid Spray in his inventory and Ada also starts with one in Assignment Ada and Separate Ways. Each character in The Mercenaries minigame starts with one in each of their inventories as well.
Resident Evil 5
"A medicinal spray that completely restores one's health."
In Resident Evil 5, the first aid spray is a full heal item that can be purchased for 1,000 gold from Chapter 1-2 and onward, and can also be occasionally found throughout the game. It can restore and refill both characters' health at once, though it requires them to stand close to each other.
Resident Evil 6
In Resident Evil 6, the First Aid Spray heals and restores all 6 blocks of health. Additionally, players can carry up to 3 cans of First Aid Spray at a time. It can revive a dying player without the help of a partner provided that the player has equipped it before being sent into dying state since in this state, it restricts any other actions except for crawling and shooting. It can also revive a partner without resuscitating or wasting your tablets.
In Resident Evil: The Umbrella Chronicles, the first aid spray is an item that appears once per level and will be automatically used when the player's health drops to zero, completely refilling the player's health (similarly to an "extra life" item). Oddly enough, the game's instruction manual says that you can carry up to 3 first-aid sprays at a given time, however there is only one First Aid Spray per-level, and they don't carry over to the next if you manage to survive without using the one you have acquired.
Operation Raccoon City
First Aid Sprays are found scattered around the campaign maps and multiplayer maps of Resident Evil: Operation Raccoon City. You can only carry one at a time unless you are playing as Bertha, Harley, or Ada, and you have the passive ability First Aid Proficiency in which you can carry more depending on your level in that skill. The First Aid Spray has an area of effect, which means you can heal multiple teammates depending on how close they are to you. They only cure about 75% of your health unless you have the passive skill Field Medic in which, depending on your level, you can cure up to 100% of your or your teammates health.
Resident Evil 2 (2019)
"A healing spray that will restore you to full health."
First Aid Sprays in the remake of Resident Evil 2 behave similarly to its past iterations, it can only be used while in the inventory screen.
- In the beta version of Resident Evil 2 and the trial version of Biohazard 2, there existed a purple Antidote Spray that was used like a First Aid Spray, but it also cured poison. This was likely removed in the final version due to the similar effects with the Mixed Herbs (G+R+B).
- In Resident Evil 3: Nemesis, there is a F. Aid Box that can carry up to three First Aid Sprays while only taking up a single item slot. In Easy Mode, Jill will begin the game with one in her inventory. In Hard Mode, two F. Aid Spray Boxes can be obtained by defeating Nemesis-T Type in optional battles - the first is dropped on his third defeat, while the second drops after his sixth defeat.