Guthix rest

Guthix rest is a potion. It is made during One Small Favour from a Clean harralander and a Clean marrentill. To make it use a Clean harralander on a vial of water, then add one clean marrentill. This makes a three-dose Guthix rest. Making Guthix rest gives a total of 59.5 Herblore experience.

After One Small Favour is completed, it can still be made, however the combined cost of all the required herbs would be 445 coins on the Grand Exchange, making it far preferable to purchase there rather than waste time and gold making them yourself. However, since they are rarely sold on the Grand Exchange, you may find that making them yourself is the better option than raising the price for priority and waiting. It still gives Herblore experience and has several useful effects. It reduces damage taken by poison by 10 lifepoints per dose, heals 200 life points per dose, restores 5% run energy and boosts the maximum life points by 50 at full health. A full four dose potion restores a total of 800 LP with the possibility of boosting the player's lifepoints over their maximum level by 200.

When first released, there was a glitch that caused the potion to restore all of the player's health. The glitch was quickly fixed. However, many players were banned for abusing the glitch to gain an unfair advantage in PvP situations.

Attempting to make this potion by adding the herbs to the vial of water before speaking with Sanfew, even partially into the quest, will result in: "You have no idea what effect this would have."

Glitch
The Guthix rest glitch was discovered in the One Small Favour quest.

This item instantly restored 100% of your Hitpoints when a player drank it. It was only supposed to boost the maximum life points if a player was at full health. This glitch was abused to win duels at the Duel Arena and to player kill without dying. This was fixed by Jagex shortly after discovery.

The glitched potion had the following effects:
 * Cure from poison
 * Restore some run energy
 * Fully heal and boost hitpoints by 5.

Trivia

 * The Guthix rest used to be drunk from a teacup.

Guthix rest