The Dying Will Pill is similar to the Dying Will Bullet yet slightly less potent, therefore producing a less powerful Dying Will Mode. It is given to Tsuna by Basil during the Varia Arc for emergency use when Reborn isn't around and cannot use the Dying Will Bullet.
So far, the benefits have outweighed the consequences, as the Dying Will Pills have always been enough for Tsuna to take down whomever he was battling. Tsuna often used them instead of being shot with a Dying Will Bullet by Reborn when they were training or when he was in battle.
To go into Hyper Dying Will Mode, two pills are needed. The appearance of the pills varies: in the anime, they look like candy, while in the manga, they look more like real pills.