How Much Friendship Do Berries Give Your Pokemon?
Many activities will increase a Pokemon’s friendship, including walking with it, fighting strong opponents with it and eating friendship-raising berries. However, these methods only increase a Pokemon’s friendship up to 255 points base friendship.
There are also vitamins and items that can increase a Pokemon’s friendship upon consumption. These include the Soothe Bell, which doubles the rate at which a Pokemon becomes friendly.
A number of vitamins will give your Pokemon a boost in friendship, doubling the rate at which they accumulate through walking and battling. These are typically obtained from the Veilstone Department store or Watt Traders and can be purchased for 10,000 Pokebux, though they can also be traded for battle points. In addition to boosting friendship, Vitamins will raise relevant base stats, as well. This is a far more expensive method to increase friendship, but is generally more effective than other methods.
A number of Berries can change the friendship level of a Pokemon on consumption, though these often have a side effect that lowers a specific stat. Grepa, Hondew, Kelpsy, Pomeg, Qualot, and Tamato berries increase friendship but lower HP, special defense, physical attack, and speed respectively. These Berries are bought from the Watt Traders for 100 PokeCoins each. In addition to these, certain Curry items will also decrease friendship. This is especially important since Pokemon will faint in battle if their friendship is too low, which will negate all the progress you made through fighting and cooking.
Keeping a Pokemon around and battling with it is one of the best ways to raise its friendship. This method does not have an upper limit like Vitamins but it should be used in combination with other methods.