The purpose of the study is to determine whether pharmacologic delay using minoxidil in patients undergoing bilateral risk reducing mastectomy with reconstruction could achieve improvement in flap perfusion and flap viability at the time of surgery. Patients will undergo randomization of their breasts to determine which breast will receive the experimental intervention and which breast will serve as the internal control (receive placebo). The experimental breast will receive the novel pharmacologic delay treatment, 5% minoxidil, while the internal control breast will receive the current standard of care, which does not include any topical application prior to surgery - a placebo control will be used.

This will be a triple-blind study, where both the participants and investigators will be blinded to which breast will receive the intervention. The patients will receive two bottles "compound A" and "compound B" with directions from the pharmacy for which compound to apply to each breast.

Product will be applied for 2 weeks prior to planned surgery. Surgery will proceed without any changes to standard practice.

Inclusion Criteria:

1. Female sex > 18 years old
2. Genetic predisposition to cancer
3. Undergoing bilateral prophylactic mastectomy with same-day breast reconstruction
4. Capable of giving informed consent

Exclusion Criteria:

1. Diagnosis of breast cancer
2. History of cancer
3. Currently pregnant or planning to be pregnant (for women of child-bearing potential)
4. Male sex

High-risk for breast cancer diagnosis with desire to proceed with breast reconstruction