You’re talking about XL Candy from Pokémon GO—this item is used to push your Pokémon past level 40 and up to level 50, making them significantly stronger in high‑level raids and PvP.

What XL Candy is for

  • XL Candy is a special currency used to power up a Pokémon from level 40 to level 50.
  • You can’t actually use it until your trainer account is at least level 40.
  • Each species has its own XL Candy (e.g., Squirtle XL Candy for Blastoise), and there is also Rare Candy XL that can turn into any species’ XL Candy.

When and how to use it

Once you’re level 40+, you use XL Candy in almost the same place you use regular Candy:

  1. Open the Pokémon you want to strengthen.
  1. Tap Power Up and look at the required Stardust, regular Candy, and XL Candy.
  1. Spend the resources to push that Pokémon’s CP beyond its old cap, working your way toward level 50.

Some quick strategy:

  • Focus XL Candy on strong “meta” Pokémon you’ll use a lot in Master League or top‑tier raids (for example, strong Legendaries, pseudo‑legendaries, or your best IV shadows).
  • Avoid spending XL Candy on random or weak IV Pokémon you’re likely to replace later.

How to get more XL Candy

  • Catching Pokémon of that species (higher‑level catches tend to give more chances).
  • Walking a Pokémon as your Buddy can sometimes reward XL Candy for that species.
  • Transferring Pokémon to the Professor has a chance to give 1 XL Candy.
  • Converting 100 regular Candy into 1 XL Candy (good only if you’re overflowing with normal Candy).
  • Using Rare Candy XL, which can be turned into any species’ XL Candy and is especially valuable for hard‑to‑find Legendaries and Mythicals.

Simple rule of thumb

If you’re wondering “what to do with XL Candy” in practice:

  • Save it until you’re at least trainer level 40.
  • Invest it only into top‑tier Pokémon you know you’ll use long‑term, especially Legendaries where normal XL Candy is scarce.

If you’re not deep into Master League or hardcore raiding, it’s totally fine to stockpile XL Candy for later rather than spending it right away.

TL;DR: XL Candy is for pushing your best Pokémon from level 40 to 50; stockpile it and use it sparingly on long‑term, powerful picks, especially rare or Legendary Pokémon.

Information gathered from public forums or data available on the internet and portrayed here.