First Aid-Spray:
This spray, will recover you to full HP. They're not an option on Hard and Very Hard mode, as they are hard to come by.
 Recovery Medicine (small)
This blue medicine, will recover you 500 HP. It can be created by using George. Just mix a blue herb.
 Recovery Medicine (large)
Larger than the other, it gives you 2000 HP.
This red medicine, will make you stop bleeding. You can create it by using George. Just mix a red herb.
Herbs are essential in the game. When you're in harder modes, there will be almost no first-aid-sprays. However herbs are still easy to find. You can combine them, into a maximum of 3. Above you'll see the impact the combinations can do.
 Green Herb:
A Green herb by itself recovers 500 HP. Not much, but you can also use George to transform it in an Antidote, though that's not a very good idea.
 Blue Herb:
 Red Herb:
A Red Herb by itself is useless. However, you can use George to transform it into a Renostat, but that's the least you should do.
 2 Green Herbs:
When you combine a Green Herb with another one, you will recover 1000 HP.
 3 Green Herbs:
When 3 Green Herbs are combined the result is a little more than 1500 HP.
 Blue Herb+Green Herb:
By doing this, you will recover from Poison and gain 500 HP:
 Blue Herb+2Green Herbs:
By doing this you will gain 1000 HP and you will recover from Poison.
 Green Herb+Red Herb:
This is the second most powerful mix. When a Green Herb is combined with a Red Herb, you gain 2000 HP.
 Green Herb+Red Herb+Blue Herb:
The most powerful mix. The Blue Herb not only makes you recover from Poison, but it gives a little HP boost. You recover 2200 HP.
 Blue Herb+Red Herb:
This mixture by itself is almost useless. It only recovers you from Poison. You must mix a Green Herb to it.