what are the red herbs used for in the Gamecube version of Resident Evil?

Answer 1

Here is an explanation of all the herbs, so you understand the importance of combining. You can combine up to three herbs, and depending on which herbs you combine the effects will differ.

Green + Red: On its own, a red herb is useless. However, if you combine it with a green herb the mixture will heal you completely, no matter how hurt you are and no matter how large your health bar is.

Green + Yellow: Like the red herbs, yellow herbs are useless on their own. Once you combine a yellow herb with a green herb, the mixture gains the ability to increase your maximum health (it actually makes your health bar longer), as well as refilling a small portion of your health.

Green + Red + Yellow: This mixture combines the effect of both recipes listed above. Not only will this mixture refill your health completely, but it also increases your maximum health capacity.

Green + Green + Green: Combining three green herbs will create a mixture that refills your health completely, exactly like a green/red combination. And while having this combination is great for conserving space, it does have on negative effect. If you mix all of your green herbs, you'll be left with nothing to combine with any red and yellow herbs you find later on. And since both red and yellow herbs are useless on their own, you'll essentially have wasted potential healing power.