This chapter establishes that offers of compensation are required to enable some plasma donors to give their informed consent to donate. Offers of compensation provide information to prospective donors concerning the economic value of their donation. Once they have this information some donors reconsider their original intention to donate. These empirical claims are then combined with an ethical axiom that is widely accepted by medical professionals, bioethicists, and moral philosophers who work on bioethics: That (if possible) persons should give their informed consent to any medical procedures that they undergo. This combination of claims leads to the conclusion that to protect prospective donors’ ability to give their informed consent to the donation of their plasma, plasma centers should not be prohibited from offering them compensation. In arguing for this conclusion this chapter considers and rejects the “professional standard” of informed consent. It then argues that the two most defensible standards by which the relevance of information could be assessed in the context of securing a person’s informed consent to how she is treated – the “reasonable person standard” and the “subjective standard” – both support the conclusion that the ethical requirement to secure patients’ informed consent to their medical treatment requires that plasma centers be allowed to offer compensation to donors.