Pokémon Red and Blue / GAME HISTORY

Why Does Leech Seed Damage Grow After Toxic in Pokémon Red and Blue?

Toxic’s growing counter can affect the HP taken by Leech Seed.

By Patchlo Editorial Desk · Published October 27, 2026 · Sources checked October 27, 2026

Scope: Original Game Boy Red and Blue; community-documented behavior.

Apply both effects to the same target

The combination needs one target carrying the relevant effects. Toxic badly poisons it; Leech Seed then drains it at the end of the turn. Under the documented interaction, the amount taken by the seed grows instead of remaining separate from Toxic’s escalation.

1. Inflict Toxic on the target.
2. Land Leech Seed on that same target.
3. Compare the seed damage on successive turns.

Rest does not settle the whole question

The account also includes a target that was badly poisoned and then used Rest. Removing the visible poison does not necessarily remove the counter affecting Leech Seed. That explains why checking only the status label can miss what is still influencing the damage.

Do not apply this to every later release

This is a Generation I interaction attributed to community battle research. The source distinguishes Generation II onward. It leaves some Stadium verification incomplete, so this article does not invent a Stadium fix date or extend the result to every console version.