This round's bullet is made of solid lead with a polymer jacket. It will not disintegrate when it makes contact with a hard or soft target -- in fact, it is designed not to send metal fragments back at its shooter even when it strikes steel. Practically, such a bullet will perform nearly the same as a full metal jacket (FMJ) bullet as it penetrates soft tissue. As the result it will not expand during penetration, which means it will creates a narrower wound channel than a jacketed hollow point (JHP) bullet and may also pass through a target without transferring all of its available energy.
Now, to answer your question. There are better suited rounds for self-defense than this one. That said, this round is certainly capable of inflictlicting serious body injury. Any living thing struck by 124 grains of lead flying faster than 1,000 fps is going to take note of the experience. If this were the only ammunition available to you during a serious self-defense situation, you would indeed do well to take advantage of it.