What is a common disadvantage of using spermicides during intercourse?

Spermicides, while providing a means of contraception, have a common disadvantage in that they can cause vaginal or penile irritation. This irritation can be a result of the chemical agents used in spermicides, which may lead to discomfort not only for the female partner but also for the male partner during intercourse. Such irritation can potentially affect sexual enjoyment and lead to issues that may require further medical attention.

In contrast, the other options highlight characteristics that are not disadvantages. Increased pleasure is generally not associated with spermicides as they might create discomfort instead. The effectiveness rate of spermicides alone is not considered high when compared to other contraceptive methods, and they do not provide long-term protection against sexually transmitted diseases, which is a significant limitation of their use in safe sex practices.