Skill transfer could cause side effects on the donor as well as on the consumer. As mentioned in the chapter Transferable Skills  it could affect a person’s psyche. For the donor this could mean some kind of personal suffering through the temporary loss of his or her  skill or even some withdrawal symptoms. For a consumer a side effect could be psychological as well, influencing the personality of him or her. Furthermore, if someone uses skill transfer constantly he or she could develop an addiction.

When Skill transfer isn’t realized by professional companies, but by illegal institutions or unprofessional private individuals the interface could get infected. The donor could also have health problems like weakness of the immune system and dizziness, if the skill transfer isn’t done correctly as in eg “Hard Fall”.

You can find another example of a psychological side effect in the treatment “Wunderkind” where the protagonist loses his empathy.

If you want to learn more about side effects you can also check out the forum where you will find a discussion on side effects.