Inclusion Criteria:

• * Age ≥18 years
• * Self-identify as White or African American
• * Uncontrolled TRH, defined as uncontrolled blood pressure (mean 24-hour ambulatory systolic BP ≥125 mm Hg or diastolic BP ≥80 mm Hg) while being adherent to a stable (no changes in ≥30 days prior) antihypertensive regimen of 3 or more drugs, including an adequately dosed thiazide or thiazide-like diuretic (hydrochlorothiazide ≥25 mg/day or equivalent)
• * The participant agrees to have all study procedures performed

Exclusion Criteria:

• * Known hypersensitivity or contraindication to minocycline or other tetracyclines
• * Recent (≤3 months prior), ongoing, or expected use of oral antibiotics
• * Estimated glomerular filtration rate (eGFR) of \<45mL/min/1.73m2, using the MDRD equation
• * Known secondary hypertension
• * History of antihypertensive crisis, defined as any in-patient hospitalizations for antihypertensive crisis/emergency within the past year
• * History of orthostatic hypotension, defined as two or more episode(s) of orthostatic hypotension (reduction of SBP of \>20 mm Hg or DBP of \>10 mm Hg within 3 minutes of standing) in the past year
• * History of myocardial infarction, unstable angina, syncope, or cerebrovascular accident in prior 6 months
• * Evidence of alcoholism or drug abuse
• * Severe comorbid conditions (i.e., neoplasms or HIV positive or AIDS)
• * Ongoing or expected use of significant BP-interfering medications (excepting oral contraceptives)
• * Current pregnancy or anticipated pregnancy during the study.