Informed consent is at the center of the Rotterdam Convention on Prior Informed Consent and the Cartegena Protocol on Biosafety. Consistent with the idea of a negotiation ``formula,'' it encapsulates the principles underlying parties' demands by balancing the efficiency of unconstrained trade with ethically charged support for autonomy and self-determination. As a negotiated rule, informed consent translates the formula into specific procedural requirements based on risk assessment. Parties' fundamental interest to enhance food security via the two treaties is used to illustrate both the principle and rule aspects of informed consent. In addition, the value of formula analysis in negotiation theory is investigated. The article supports increased attention to informed consent in international relations, to the merits of formula analysis, and to the possibility of better understanding a fundamental objective such as food security through a formula-guided analysis of these and related negotiated outcomes.