Despite being sent all the way to Europe to rescue the president’s daughter, Leon arrives vastly underpowered for the job presented to him in the Resident Evil 4 remake. Not only was he sent in alone, but with just a single handgun (with 10 bullets) and a knife. If you want any hope of completing this mission, you will need to get every advantage you can. Aside from expanding and upgrading your arsenal, collecting as many of the game’s Yellow Herbs will be your top priority. Of the three types of Herbs — Green, Red, and Yellow — these are the rarest of them all. In total, you can only grab 17 of them in a single playthrough. You will want as many of them as possible to give Leon a much-needed buff, so here’s what Yellow Herbs do and where you can collect them all in the Resident Evil 4 remake.

Each of the three Herb types in Resident Evil 4 serves a different function. Green Herbs are for healing, Red Herbs enhance the effect of whatever Herb they’re combined with, and Yellow Herbs actually increase Leon’s maximum health. That makes them by far the most valuable of the three since, with enough of them, you can essentially double the amount of damage you can take once you max out his health.

Yellow Herbs can’t be used on their own and must be combined with at least one other Herb to get their effect. The best possible combination is one of each — Green, Red, and Yellow — since it will basically heal you to full, plus extend your life. Combining Red and Yellow is your next best option because, while it won’t heal you, you will still get a slightly larger boost to your maximum health thanks to the Red Herb enhancing the Yellow. Green and Yellow should be avoided if at all possible since you will get the smallest possible increase to your health bar. So long as you combine a Yellow with a Red each time, it will only take you 13 of the 17 to max out Leon’s health, giving you some wiggle room if you missed any.

There are 17 Yellow Herbs to grab in any one run of the Resident Evil 4 remake, but one of them is purchasable from the Merchant for three Spinels as soon as you meet him in Chapter 2. As far as the ones you need to pick up, here they are in order of appearance: